Rust Inspection and Prevention

By Bud Coburn

Rusting describes the process of the corrosion of iron and its alloy, steel.  InterNACHI inspectors, homeowners and commercial property owners should understand how rust forms and how to prevent it.  Rust is more than a cosmetic issue; it can lead to serious structural deterioration.A rusted roof with a rusted chimney vent

Rust Formation

Rusting is a common form of corrosion – an electrochemical process leading to the disintegration of a material into its constituent atoms – a category that also includes galvanic corrosion, pitting corrosion, and crevice corrosion. Rust usually appears as a red, brown or orange flaking or pitting of the metal surface.

Rust is formed when oxygen comes into sustained contact with iron in a process called oxidation. Oxygen is delivered to the metal from water, either from liquid water or water vapor. Carbon dioxide in the air combines with water to form a weak carbonic acid, dissolving the water into its component parts – hydrogen and oxygen – as well as causing some of the iron to dissolve. The free oxygen bonds with the dissolved iron to form iron oxide or rust. Oxidation catalysts, such as saltwater and air, acids and acid rain, soils, and airborne sulfur compounds, will accelerate rust formation. Rust formation is also encouraged by architectural crevices that trap liquids.  Once rust forms, its porous surface will trap additional liquids and lead to further corrosion.

Identifying Metals that Can Rust

It may be helpful for inspectors and homeowners to have some rudimentary knowledge about how to differentiate metals that can rust from metals that cannot rust. Iron and steel (including galvanized steel and stainless steel) are magnetic, while aluminum, copper, zinc, brass and silver are not magnetic. Tin is also magnetic, but its use in building construction is uncommon. Iron is typically dark in color. Galvanized steel has a dull appearance, while stainless steel is shiny and bright. Copper, which is commonly used in household wiring, has a bright, reddish color, although it can turn green when exposed to air. Aluminum, a building material commonly used in siding, is silver-colored and shiny. Professionals can perform further tests by exposing the metal to acids, or by measuring the size and color of the sparks produced when the metal is carved.

Other Facts and Figures

  • The only metals that can rust are iron and alloys that contain iron, such as steel. Other metals may become corroded but they do not technically rust. For example, the corrosion of copper and its alloys, bronze and brass, produces a green layer called patina or verdigris.
  • Prime rust conditions occur when iron is regularly exposed to saltwater and humid air. Iron is relatively unaffected by non-saltwater or dry air.
  • In 1998, rust caused an estimated $276 billion in damages, or 3.2% of the U.S. Gross National Product, according to the U.S. Federal Highway Administration.
  • The neurotoxin that causes tetanus, a disease associated with rust, is the second most deadly known neurotoxin (after Botox®). One gram of tetanospasmin can kill 6,000,000 average-size men, making it approximately 1,600,000 times more potent than King Cobra venom.

The Connection between Tetanus and Rust

Tetanus is a potentially lethal medical condition characterized by muscle spasms, difficulty swallowing, and fever. Spores of the bacteria that cause tetanus –  Clostridium tetani – lie waiting in ordinary soil, which can become easily trapped in the rough surface of rust. A dirty protruding nail or barbed wire serves as a vehicle for the bacteria to enter the body, where the spores within the dirt become activated by the lack of oxygen (as do all anaerobic bacteria) and quickly begin producing a potent neurotoxin called tetanospasm.

While rust is associated with tetanus, fears surrounding cuts from rusty metal are exaggerated for the following reasons:

  • Tetanus is extremely rare, amounting to an incidence of 0.15 cases per 1,000,000 people in the U.S., according to the Centers for Disease Control.  This rarity is largely accounted for by tetanus immunization shots. However, people who have not received recent vaccinations, such as older adults, are at increased risk for tetanus.
  • The Clostridium tetani bacteria may be found on any objects exposed to soil, including metal objects that lack any rust. Even non-metal objects can transmit Clostridium tetani.  A study of canine tetanus revealed that a large number of cases originated from cuts caused by sharp spikelets of grass known as foxtails. Any cuts caused by an object made dirty by soil, regardless of whether it is rusted or even metal, should be treated as a potential source of Clostridium tetani.

Rust in Buildings

Rust has considerably less mechanical strength than its originating metal and it will not adhere but will gradually flake off, weakening the structure. It also has a greater volume than iron, and its buildup will force apart adjacent parts, a phenomenon called “rust-smacking.”  Through this process, rust can make a structure more vulnerable to collapse from weather, impact, or even gravity. The Kinzua Bridge in Pennsylvania collapsed in 2003 due to rust smacking when its central base bolts, which held the structure to the ground, simply rusted away.

InterNACHI inspectors should be on the lookout for rust damage in the following locations:

  • concrete-encased steel. Concrete is used to protect reinforcing steel bars from environmental moisture, but the metal will rust where mechanical damage has removed a small piece of concrete and exposed the underlying rebar. Even where the concrete is intact, moisture can penetrate concrete through microscopic stress fractures. As the iron turns to rust, the expanding volume forces the adjacent layer of concrete to fall away, which exposes more metal to moisture, rusting and destructive expansion. If this situation is not detected and remedied, the deterioration will persist and cause serious structural problems. Manufacturing defects that increase the likelihood of moisture penetration include insufficient cover (less than 1-1/2 inches of concrete), insufficient air bubbles to trap moisture, cement that was mixed with too much water, and inadequate time allowed for the concrete to cure before loads were applied. For more information, consult InterNACHI’s article Detecting Corrosion in Concrete-Encased Steel;
  • water pipes. Tap water that is brown, red, orange or yellow indicates rusted water pipes, especially older, unlined cast-iron pipes. While rusty water itself is not a serious health hazard, rusting water pipes may eventually leak and cause structural damage. The corrosion may be occurring within the home’s plumbing system (indicated by discoloration of hot water, discoloration at only one or several faucets, or if the water clears after it has run for several minutes), or at the water main (indicated by discoloration of the cold water, discoloration at all of the water faucets, or if the water does not clear after it has run for several minutes). Further assessment should be conducted by a qualified plumber;
  • roofs. Roofs are exposed to snow and rain, and unprotected roofs that are made from steel are prone to rust. The rust should be scraped off before paint or a rust-resistant sealant is applied. Many rust-damaged metal roofs have been painted over without repair, leading to moisture intrusion into the house. This type of defect may only be detected through the use of an infrared camera, which is why prospective homebuyers should hire an Infrared-Certified® InterNACHI inspector and consult InterNACHI’s article IR Cameras: Inspecting for Moisture Intrusion. Rust stains can also be found on non-metal roofs where rainwater has washed rust from metal roof components, such as chimneys, flashing and antenna mounts. Inspect these Courtesy of InterNACHI member John Gromkoskiitems for rust damage. If the stain is, in fact, rust, and not algae, mold, moss or soot from the chimney, inspect nearby metal components for rust damage;
  • chimneys. Decaying leaves and pine needles create an acidic solution that will eat away at the galvanized coating on metal chimney covers, leaving them exposed to rusting from rain and melting ice and snow. The weakened metal will permit the entry of water inside the chimney, causing further rusting. This condition is less common in newer stainless steel chimneys, which are better suited for rust prevention, as well as chimney covers that slope in a way that prevents water from pooling. Observe the rusted chimney pictured at right, courtesy of InterNACHI member John Gromkoski;
  • fuel oil tanks. Most fuel oil tanks are made from steel and are thus vulnerable to rust, which can damage the tank and cause the oil to leak. Leaked fuel oil is an environmental pollutant and fire hazard.  Oil can also damage building materials. Rain and snow will endanger above-ground tanks, while groundwater will endanger buried tanks. While the presence of rust does not conclusively mean that the tank is unsafe, check for visible leaks, an oily smell, or dying vegetation above buried tanks. For more information, read InterNACHI’s article on Home Heating Oil Tanks and Underground Fuel Storage Tank Hazards and Inspection;This above-ground oil storage tank has severely rusted and can pose environmental hazards as well as threaten the adjacent structure.
  • fences. Steel fences are highly susceptible to rust because they are exposed to rain and snow and their maintenance is often neglected by homeowners.
  • nails. Nails that are not stainless steel or galvanized (or if the galvanized coating has been sanded away or eroded) will rust when exposed to water or humid air. The rusting of nails within wood indicates that the wood is moist or high in tannic acid, which will react with ordinary steel to produce black rust stains. Aside from their aforementioned association with tetanus, rusted nails will not provide adequate support, which increases the chance of collapse of the structure they’re nailed into; and
  • electrical panels. A rusted electrical panel is a serious issue because rust indicates the presence of moisture, which can disrupt power flow, cause heat buildup and lead to a fire, or cause electrocution. Moisture may have entered the panel through worn, frayed, fabric-covered service entrance cables, from the connector at the top of the electrical meter, or the opening where the cable passes through the building wall. Check for rusting on steel service panel components, screw connectors, the wiring connection, and the connection between the service entrance cable to the main breakers. A rusty electrical panel should be inspected by a qualified electrician.

Rust Prevention Techniques

The following techniques may be used to enhance corrosion resistance in iron and steel:

  • Bluing is a technique that changes iron’s atomic structure from Fe into Fe3O4, which is more corrosion-resistant than iron.
  • Galvanized steel is steel that has been coated with a layer of zinc (or cadmium for saltwater applications) to provide resistance against rusting. However, this layer can wear away, typically at seams and joints or where the layer has been pierced.
  • Stainless steel is another rust-resistant material.  The chromium in stainless steel serves the same purpose as zinc in galvanized steel, except the chromium is mixed throughout the metal, rather than as a coating. As a result, the chromium cannot be worn away, making stainless steel comparatively more corrosion-resistant than galvanized steel.
  • Coatings and paint can form a barrier between iron or steel and environmental moisture. Slushing oil is a common wax-based product applied to metal to minimize corrosion. Concrete and other alkaline coatings will slow down the rusting process.
  • Cathodic protection is a technique used to prevent rusting and is often used in concrete-encased steel and storage tanks by supplying an electrical charge that suppresses the electro-chemical reaction that causes rusting. A sacrificial anode that can be more easily corroded – commonly made of zinc, aluminum or magnesium – is attached, making the steel or iron act as the cathode in the electrochemical reaction.
  • Weathered steel, also known as COR-TEN® or Corten® steel, is steel that has been altered to gradually develop a rust-resistant coating in response to the effects of weather. Ironically, the coating resembles rust and is used in building facades to convey a rustic appearance. One downside of its use is that older weathered-steel formulations can stain nearby sidewalks and buildings where rainwater has drained from the steel, although manufacturers have since remedied this defect.
  • Rusting is slowed significantly when the relative humidity is brought below 50%, which may be accomplished through the use of a dehumidifier or silica desiccant, or by other means. Also, increasing the metal’s surface temperature can control condensation.
  • Saltwater is a better electrolyte than non-saltwater, as the presence of salt will accelerate the rusting process. Houses in coastal areas or near roads salted by snowplows are at heightened risk. Homeowners should scrub salt-laden water spray from their homes.
  • Keep the metal surfaces clean. Common hydroscopic contaminants, such as zinc chloride and sodium nitrate, will suck moisture from the air and trap it on the metal surface to accelerate rusting.  Metal surfaces should be periodically cleaned of accumulated dirt and other debris.

Rust Removal Techniques

Homeowners should follow the aforementioned rust prevention techniques because rust can be very difficult to remove once it has formed. Rust removal techniques do exist, however, and InterNACHI inspectors may recommend the following methods to clients in situations where their implementation is cost- and labor-effective:

  • Mechanical scraping is scraping by hand using a wire brush.  This is the most common and least expensive way to remove rust. Paints or rust-inhibitive primers may then be applied to protect the metal surface against future corrosion.
  • Low-pressure sand-blasting uses high-velocity sand, iron slag or copper to remove rust and other debris. Pressure should not be so high as to damage the metal surface.  Surrounding materials should be protected against damage. Wet sand-blasting is not recommended because it can penetrate joints and cause instantaneous rusting.
  • Rust can be dissolved from iron and steel components by submerging them in vats of phosphoric, sulfuric, hydrochloric or oxalic acid. Larger or permanently installed metal cannot be treated in this way because items must first be removed and transported to a shop.
  • Rust can be powdered or flaked off by flame cleaning, which involves the use of an intensely hot oxyacetylene torch. While effective, this method is dangerous, expensive, and must be performed by skilled operators.
In summary, rust is the product of an electrochemical reaction between carbon dioxide, oxygen and iron. A variety of rust prevention techniques are available to prevent unsightly rust from developing and damaging building components.  InterNACHI inspectors can educate their clients on how to identify metal components that are at risk, how to prevent rust from forming, and how to address the damage caused by rust.

Rubber Flooring Inspection

By Bud Coburn

Rubber flooring is flooring made from either natural tree rubber or recycled rubber from vehicle tires. Long-touted for its slip-resistant qualities and durability in gyms, hospitals, factories, and other commercial buildings and establishments, rubber flooring is increasingly being installed in kitchens, Installation of interlocking rubber tiles; photo courtesy of Best Garage Floor Tilesgarages, playrooms and other residential applications.  InterNACHI inspectors who perform residential and commercial inspections are likely to encounter rubber flooring at a diversity of venues, so knowing how to inspect for their condition and common defects can help them properly advise their clients.
A Brief History of Rubber
The ancient Mayans made rubber balls from plant and tree sap as long ago as 1600 BC.  In the early 19th century, inventors Charles Goodyear and Nathaniel Hayward mixed sulfur and gum plastic with rubber under high heat in a process called vulcanization to create a more resilient product. Material shortages and demand for an even more durable rubber in the early 20th century led to the creation of synthetic rubber made entirely from man-made ingredients. Today, rubber used to make floors may be synthetic, recycled primarily from used car and truck tires, or natural, formed from extracted sap from the rubber tree Hevea brasiliensis.
Rubber Flooring Types and Applications

Manufacturers generally offer rubber flooring in the following two forms, which can be selected based on the desired location, installation requirements and appearance:

  • tiles, which are easier to install than sheets because they come in smaller, individual pieces that can be moved and adjusted with less difficulty. Homeowners can choose a patterned look to make the seams less noticeable; and Speckled rubber tiles; photo courtesy of
  • sheets, which boast greater moisture resistance because they have fewer seams, but they require  more precise installation than rubber tiles. A professional installer may be required.

Additionally, rubber flooring may be attached to the floor in the following ways:

  • glued down, in which the tiles or sheets are glued to the subfloor. Glued rubber flooring will stay in place and offers excellent durability;
  • loose-lay, in which rubber flooring is attached to a smooth and clean flooring material with double-sided carpet tape; and
  • interlocking, in which tiles lock into each other’s pre-cut grooves. Installation is easy because no glue or tape is required, allowing them to be installed over many types of existing flooring.
Advantages of Rubber Flooring
Available in a huge array of patterns — from speckled and interlocking to an inexpensive imitation of marble — and in myriad colors, rubber affords homeowners great design flexibility. Designs may even be tailored to their application, such as the incorporation of bold lines to define pathways in a hospital.
Some other advantages of rubber over other types of flooring are as follows:
  • Glue may not be required. Unlike most other flooring options, rubber tiles (depending on installation requirements) often require only carpet tape or no adhesive at all. This makes installation easier and protects indoor air quality from the odor and toxic compounds released by the glue required for installing other types of flooring products.
  • Rubber flooring beats many other types of flooring in terms of longevity.  When properly maintained, it can last the entire lifetime of a building. A urethane can be applied on top of the rubber to increase its durability and adds a glossy finish to the end product.
  • Easy on the joints and comfortable to stand on for long periods of time, the inherent elasticity of rubber floors protects dropped breakables, unlike ceramic tiles and other alternatives. This quality also protects the floor against items that are dropped on it, while wooden, ceramic and linoleum floors are more easily chipped and scratched. Gym floors are generally made of rubber, which can protect users as well as absorb the impact from dropped dumbbells and other athletic equipment.
  • Environmentally speaking, rubber flooring is low-impact. According to the U.S. Environmental Protection Agency, the U.S. generates approximately 290 million scrap auto tires per year, which accounts for 2% of all solid waste. Millions of scrap tires are buried or burned, filling the air and water with benzene, styrene, phenols, butadiene, and other toxic chemicals. Re-forming them into new tires is limited by product quality constraints, but they can easily be reused for rubber flooring, mitigating one of the largest and most problematic sources of waste. Rubber flooring can also be removed many years later and reinstalled in new buildings, thus eliminating the need to expend energy and deplete resources to manufacture new flooring material. Natural rubber is taken from trees, which are harvested responsibly and are a renewable resource.
  • It is acoustically insulating. Rubber provides much better sound dampening than vinyl, tile, and other hard surfaces. It can even be installed beneath wooden floors to eliminate creaking.
  • It is anti-static, so it won’t create static shocks during dry winters.
  • Probably its greatest asset is that it’s naturally slip-resistant. Rubber has a high coefficient of friction in wet and dry conditions relative to flooring alternatives, which makes it a good material around pools and other slippery areas. A surface textured in knobs will further increase slip resistance. To further illustrate this quality, consider the Olympics, where billions of eager eyes watch gymnasts leap and land on the sweat-laden floor. A slip under these circumstances could be disastrous, which is why Olympic floors are made of rubber.
Disadvantages of Rubber Flooring
InterNACHI inspectors, homeowners and commercial site managers should be aware of the following disadvantages and hazards associated with rubber flooring:
  • flammability. All rubber is flammable, although various grades of fire-retardant rubber flooring are available, but the more flame-resistant materials are more expensive;
  • lack of versatility. Carpet and wood floors may better suit traditional home décor, such as living room and bedroom applications;
  • oxidation. Interactions with light, heat or certain metals will cause rubber to oxidize and become brittle;
  • chalking. Exposure to inorganic fillers will deteriorate rubber flooring and cause it to become dull;
  • softening and staining. This can be caused by interactions with oil, fatty acids, petroleum-based products, copper and solvents;
  • loosening and lifting of seams. Rubber tiles are prone to moisture damage at the seams, which may allow additional moisture to penetrate into the subfloor. Rubber sheets protect better against moisture due to their lack of seams;Tire landfill; photo courtesty of Electronic Recyclers International
  • odor. Rubber floors made from recycled tires have a characteristic smell that, while harmless, is found by some users to be unpleasant. The smell will lessen over time but will never go away completely. Problematic odors are especially prevalent in rubber floors manufactured outside the U.S. under low-quality standards, and they’re glued together with strong-smelling urethane adhesives rather than the using the process of vulcanization. Some manufacturers recommend their recycled rubber floors not be installed in enclosed, unventilated spaces. Homeowners and commercial site owners can choose virgin rubber made from rubber trees, which is more expensive but lacks the odor associated with other rubber products; and
  • off-gassing of volatile organic compounds (VOCs). While the Internet is flush with claims that the off-gassing from rubber flooring is limited to the harmless aforementioned odor, we at InterNACHI reviewed the only controlled study that attempted to measure the VOCs released by recycled rubber in floors. The 2010 study performed by California’s Public Health Institute titled Tire-Derived Rubber (TDR) Flooring Chemical Emissions Study presented the following findings:
    • TDR and new rubber (NR) flooring products still emit a myriad of VOC chemicals, and their release is not uniform among the different products. A minority of products released excessive amounts of chemicals; and
    • Xylene, butylated hydroxytoluene, ethylbenzene, toluene, formaldehyde and acetaldehyde were found in a range of products. Benzene and carbon disulfide were above the health threshold in one or two samples… [S]ome of the identified chemicals do not yet have health-based standards, making their health impacts difficult to assess. 

Based on their findings, the study’s authors make the following suggestions:

    • TDR and NR flooring may be acceptable for indoor use, although products designated for exterior or exterior-interior use should generally be avoided indoors.
    • Ample pre-occupancy “flush out” (or off-site pre-conditioning) is appropriate when TDR and NR flooring products are used indoors.
    • Further refinement and testing of rubber-based products are necessary before these products can be promoted for wide use in most indoor environments.

Care and Maintenance

InterNACHI inspectors can pass along the following care and maintenance tips to their clients:
  • Apply a protective finish coat soon after the floor is installed because the rubber surface will more readily scuff and attract soil during the first six to 12 months following installation. Do not apply an excessive number of coats of finish on soft rubber floors, as they can cause cracking and peeling. To ensure that this coating adheres to the newly installed flooring, it should be scrubbed with a mild pH stripper to remove any mold releases, paraffin, waxes, and other debris that may be left over from the manufacturing process. As the floor ages, it will harden and become easier to clean.
  • Daily vacuuming is encouraged to keep dust to a minimum. Never clean a rubber floor with grit brushes or soiled cleaning pads. If the flooring cannot be fully cleaned with a vacuum, a damp mopping with a solution of mild soap and water will usually be sufficient. Never use acidic solvents or acetone because they may cause discoloration.  Avoid the use of turpentine or petroleum-based cleaners, as they are likely to make the rubber sticky and can permanently damage the chemical composition of the floor. Do not let the cleaning solution stand on the rubber floor for long periods of time.
  • Avoid the use of high-speed burnishers on rubber floors because they can cause burning, scalping or melted floor tiles.
  • In a kitchen application, quickly clean spilled grease, and ask your flooring contractor about the grease-resistant properties of the floor.
In summary, rubber flooring is a durable flooring material commonly used in commercial venues that is increasingly being used in residential settings for its ease of installation, decreased maintenance requirements, and eco-friendliness. InterNACHI inspectors, homeowners and commercial site managers can make informed decisions regarding the qualities that make the material attractive or possibly unsuitable, depending on the application.

Roofing Underlayment Types

By Bud Coburn

There are three basic types of underlayment used beneath roofing materials:
  • asphalt-saturated felt;
  • rubberized asphalt; and
  • non-bitumen synthetic.
One of the most common types of underlayment used in residential, steep-slope applications is black, ashphalt-saturated felt paper.  Felt underlayment may be made from either organic or fiberglass substrate, although the organic is much more common.  It’s called “organic” underlayment because it has a cellulose base.
Felt underlayment is water-resistant, but not waterproof.  It’s available in two thicknesses:  15-pound and 30-pound.  Fifteen-pound felt has a perm rating of about 5, although this number can rise in high-humidity conditions.
Thirty-pound felt is more resistant to damage during installation of the roof-covering material, and will protect the roof longer if it should somehow become exposed to weather. The difference is obvious, once you see them together. Thirty-pound felt is much thicker and stiffer.


Underlayment: overlap comparison


Slope Limitations


In low-slope roofs, which include 2:12 up to 4:12, felt courses should overlap a minimum of 19 inches. This will provide a double layer of underlayment across the entire roof.
In steep-slope roofs (4:12 and steeper), the upper courses of felt underlayment should overlap lower courses by at least 2 inches. You can see the difference between the underlayment overlapped 19 inches on the roof to the right and overlapped 2 inches on the roof to the left. In Figure 1 the lower roof is low slope with a 19-inch overlap and the upper roof is steep slope with a 2-inch overlap.


windstrip installed
Felt is usually fastened with staples, but in high-wind areas, plastic windstrips may be used along the edges to prevent tearing.


Felt may also be attached in high-wind areas using plastic caps. Plastic caps offer better wind resistance than staples, and help prevent leakage through the holes made by the fasteners.


Edge Metal Laps


Felt underlayment should overlap the edge metal at the eaves and be overlapped by edge metal on the rakes. This is also the case for rubberized asphalt underlayment, but not necessarily for synthetics.




Asphalt-saturated felt may fail for a number of reasons:

Poor Quality
A number of ASTM standards exist which offer specifications for asphalt-saturated felt.


Many manufacturers produce asphalt-saturated paper labeled “Underlayment,” “15-lb.” or “30-lb.,” which do not comply with any standards, and which are often saturated to a lower level than an ASTM-compliant underlayment. These underlayments typically absorb water more readily, and fail sooner. Water absorption can cause wrinkling as the product expands. These wrinkles may telegraph through to roof-covering products, such as thinner asphalt shingles.


Water from the felt may be absorbed by the roof deck, which can cause problems with expansion and contraction of the deck.


You won’t be able to tell by looking whether a product complies with any standards, but if you see what looks like premature failure or distortion of the underlayment, it may be caused by sub-standard underlayment.
Loss of Volatiles


Over time, volatile compounds in the asphalt will dissipate, and the underlayment will become more fragile and moisture-absorbent. This will happen more quickly when felt is exposed to heat. The source of heat may be a warm climate, a particular type of roof-covering material, or poor roof-structure ventilation.
UV Exposure
Anywhere felt underlayment is exposed directly to sunlight, UV radiation will accelerate its deterioration. These poorly-bonded shingles were attached with staples on a home located in a high-wind area.


Installation Damage


When the roof-covering material is being installed, the underlayment takes a beating and may be damaged by footfall or other materials.




In the future, asphalt-saturated felt underlayment will probably be used less and, by 2014, it will likely no longer be installed at all.  Asphalt is basically the residue left over from the process of refining crude oil.  As the price of oil has increased, refining techniques have been developed that extract the maximum amount of high-quality products from the crude.


These techniques, involving the use of  coker units, result in a residue of powder instead of the sludge from which asphalt is normally produced. With less asphalt being produced, an allocation program has been established for which the asphalt produced each year is allocated in limited amounts to manufacturers of asphalt shingles and underlayment.


Since shingles produce a higher profit margin than underlayment for the amount of asphalt used, most manufacturers are phasing out asphalt-saturated underlayments in favor of synthetic underlayments.   Although they fluctuate with raw material prices, as of 2010, prices for felt and synthetic underlayments were similar.


Various types of rubber-like materials are also used as underlayment and are generally referred to as “rubberized asphalt.” These typically have adhesive on one side, which is protected by a peel-off membrane, making them self-adhering. The rubber-like qualities of these underlayments make them self-sealing, meaning that they seal well around fasteners, such as staples and nails.

Rubberized asphalt underlayments are manufactured to meet different requirements:

  • They may have polyethylene or polyester bonded to the upper surface to provide non-skid and weather-resistant qualities.
  • They may have a polymer film bonded to the weather surface to improve moisture resistance.
  • They may be fiberglass-reinforced.
  • They may have a mineral coating on the weather surface.

They may be formulated for use in high-temperature situations.  Some underlayments are designed to resist heat up to 250° F without degradation of the adhesive.  This allows them to be installed under metal roofs an in harsh environments.

The asphalt may be polymer-modified.

Polymer-Modified Bitumen


The terms “modified bitumen” is often used when referring to asphaltic roofing materails.  Sometimes, this term is shortened to “mod-bit.”  The term “bitumen” is a generic name applied to various mixtures of hydrocarbons.  One of these mixtures is the asphalt used in underlayment, asphalt shingles, and built-up roofing.  It’s a common term in the roofing industry.


To improve various characteristics such as strength and elasticity, bitumen is sometimes modified using polymers which give it plastic-like or rubber-like properties, depending on which process is used.


Polymers are materials made of molecules which are custom-designed to give the material specific properties. Polymers are used in many different types of roofing products to increase their resistance to damage and deterioration.


You may also hear the term “cross-linked polymer” used.  Molecules in cross-linked polymers actually bond to each other at the atomic level; they actually share atoms, which greatly increases the strength of the material.

Selvedge Edge


Rolls of rubberized asphalt underlayment may come with a selvedge edge along one side of the roll. The selvedge edge is designed to create a strong, watertight seal along the edges where rolls overlap. The selvedge edge should always be along the top edge when the underlayment is installed in courses across a roof.


selvedge edge



Non-bitumen synthetic underlayments are made from polypropylene or polyethylene. These synthetic polymers are also used to make a huge variety of other types of products, from food-storage containers and rope, to long underwear.




Like other underlayment materials, the use of synthetics has both advantages and disadvantages.


Among their advantages include their light weight and high strength.  They are also typically non-skid.


Synthetics are resistant to fungal growth and are wrinkle-free, since they don’t absorb moisture. Although they can be designed as moisture-permeable, they are typically considered moisture barriers.


They’re also very resistant to UV damage and can be left exposed to weather for periods from six months to a year, depending on the manufacturer’s recommendations.




As of 2010, there are some concerns with synthetic underlayment. According to the National Roofing Contractors Association:

  • To date, there are no applicable ASTM standards for these products.
  • Many synthetic underlayments don’t meet current building code requirements
  • Use of these underlayments may void some manufacturers’ material warranties for certain roof coverings (such as asphalt shingles).
Concerns from other sources include the following:
  • Wicking can be more of a problem than with felt underlayment. Installation along the roof eave is different with some types of synthetics.
  • If the installer fails to read and follow the manufacture’s installation instructions and instead installs it like they would if they were using felt, they may create moisture problems.


synthetic underlayment


As an inspector, you are not responsible for identifying the type of underlayment, but it’s a good idea for you to know what types exist and some of their properties.
Although companies who manufacture synthetic underlayment may also manufacture similar-looking housewrap, housewrap does not meet roofing underlayment requirements. Housewrap installed as underlayment is a defective installation. Underlayment is usually thicker than housewrap. In the photo above, you can see the difference between the two.


Slope Limitations 


Slope limitations will vary by manufacturer. Some specify a greater overlap for low-slope roofs, and some don’t.


Roof Edges


To avoid problems from wicking moisture, many synthetic underlayments are designed to wrap around the roof edge and protect the edges of the roof sheathing. The edge metal is installed over the underlayment at both the eaves and rakes.




Fastening is generally done with plastic caps or roofing nails. The use of staples is discouraged because synthetics are not self-sealing.
In summary, roofing underlayment is an essential component to the roofing materials’ ability to withstand the elements, protect a home’s interior, and prolong its service life.  The more an inspector understands about a roof’s components, the better he can spot problems and deficiencies during an inspection.


By Bud Coburn


Roofs play a key role in protecting building occupants and interiors from outside weather conditions, primarily moisture. The roof, insulation and ventilation must all work together to keep the building free of moisture. Roofs also provide protection from the sun. In fact, if designed correctly, roof overhangs can protect the building’s exterior walls from moisture and sun. The concerns regarding moisture, standing water, durability and appearance are different, reflected in the choices of roofing materials.
Maintaining Your Roof
Homeowner maintenance includes cleaning the leaves and debris from the roof’s valleys and gutters. Debris in the valleys can cause water to wick under the shingles and cause damage to the interior of the roof. Clogged rain gutters can cause water to flow back under the shingles on the eaves and cause damage, regardless of the roofing material. including composition shingle, wood shake, tile or metal. The best way to preserve your roof is to stay off it. Also, seasonal changes in the weather are usually the most destructive forces.
A leaky roof can damage ceilings, walls and furnishings. To protect buildings and their contents from water damage, roofers repair and install roofs made of tar or asphalt and gravel; rubber or thermoplastic; metal; or shingles made of asphalt, slate, fiberglass, wood, tile, or other material. Roofers also may waterproof foundation walls and floors.
There are two types of roofs:  flat and pitched (sloped). Most commercial, industrial and apartment buildings have flat or slightly sloping roofs. Most houses have pitched roofs. Some roofers work on both types; others specialize. Most flat roofs are covered with several layers of materials. Roofers first put a layer of insulation on the roof deck. Over the insulation, they then spread a coat of molten bitumen, a tar-like substance. Next, they install partially overlapping layers of roofing felt, a fabric saturated in bitumen, over the surface. Roofers use a mop to spread hot bitumen over the surface and under the next layer. This seals the seams and makes the surface watertight. Roofers repeat these steps to build up the desired number of layers, called plies. The top layer either is glazed to make a smooth finish or has gravel embedded in the hot bitumen to create a rough surface. An increasing number of flat roofs are covered with a single-ply membrane of waterproof rubber or thermoplastic compounds. Roofers roll these sheets over the roof’s insulation and seal the seams. Adhesive mechanical fasteners, or stone ballast hold the sheets in place. The building must be of sufficient strength to hold the ballast.
Most residential roofs are covered with shingles. To apply shingles, roofers first lay, cut, and tack 3-foot strips of roofing felt lengthwise over the entire roof. Then, starting from the bottom edge, they staple or nail overlapping rows of shingles to the roof. Workers measure and cut the felt and shingles to fit intersecting roof surfaces and to fit around vent pipes and chimneys. Wherever two roof surfaces intersect, or where shingles reach a vent pipe or chimney, roofers cement or nail flashing strips of metal or shingle over the joints to make them watertight. Finally, roofers cover exposed nailheads with roofing cement or caulking to prevent water leakage. Roofers who use tile, metal shingles or shakes follow a similar process. Some roofers also water-proof and damp-proof masonry and concrete walls and floors. To prepare surfaces for waterproofing, they hammer and chisel away rough spots, or remove them with a rubbing brick, before applying a coat of liquid waterproofing compound. They also may paint or spray surfaces with a waterproofing material, or attach a waterproofing membrane to surfaces. When damp-proofing, they usually spray a bitumen-based coating on interior or exterior surfaces.
A number of roofing materials are available…


Asphalt is the most commonly used roofing material. Asphalt products include shingles, roll-roofing, built-up roofing, and modified bitumen membranes. Asphalt shingles are typically the most common and economical choice for residential roofing. They come in a variety of colors, shapes and textures. There are four different types: strip, laminated, interlocking, and large individual shingles. Laminated shingles consist of more than one layer of tabs to provide extra thickness. Interlocking shingles are used to provide greater wind resistance. And large individual shingles generally come in rectangular and hexagonal shapes. Roll-roofing products are generally used in residential applications, mostly for underlayments and flashings. They come in four different types of material: smooth-surfaced, saturated felt, specialty-eaves flashings, and mineral-surfaced. Only mineral-surfaced is used alone as a primary roof covering for small buildings, such as sheds. Smooth-surfaced products are used primarily as flashing to seal the roof at intersections and protrusions, and for providing extra deck protection at the roof’s eaves and valleys. Saturated felt is used as an underlayment between the roof deck and the roofing material. Specialty-eaves flashings are typically used in climates where ice dams and water backups are common. Built-up roofing (or BUR) is the most popular choice of roofing used on commercial, industrial and institutional buildings. BUR is used on flat and low-sloped roofs and consists of multiple layers of bitumen and ply sheets. Components of a BUR system include the roof deck, a vapor retarder, insulation, membrane, and surfacing material. A modified bitumen-membrane assembly consists of continuous plies of saturated felts, coated felts, fabrics or mats between which alternate layers of bitumen are applied, either surfaced or unsurfaced. Factory surfacing, if applied, includes mineral granules, slag, aluminum or copper. The bitumen determines the membrane’s physical characteristics and provides primary waterproofing protection, while the reinforcement adds strength, puncture-resistance and overall system integrity.

Most metal roofing products consist of steel or aluminum, although some consist of copper and other metals. Steel is invariably galvanized by the application of a zinc or a zinc-aluminum coating, which greatly reduces the rate of corrosion. Metal roofing is available as traditional seam and batten, tiles, shingles and shakes. Products also come in a variety of styles and colors. Metal roofs with solid sheathing control noise from rain, hail and bad weather just as well as any other roofing material. Metal roofing can also help eliminate ice damming at the eaves. And in wildfire-prone areas, metal roofing helps protect buildings from fire, should burning embers land on the roof. Metal roofing costs more than asphalt, but it typically lasts two to three times longer than asphalt and wood shingles.


Wood shakes offer a natural look with a lot of character. Because of variations in color, width, thickness, and cut of the wood, no two shake roofs will ever look the same. Wood offers some energy benefits, too. It helps to insulate the attic, and it allows the house to breathe, circulating air through the small openings under the felt rows on which wooden shingles are laid. A wood shake roof, however, demands proper maintenance and repair, or it will not last as long as other products. Mold, rot and insects can become a problem. The life-cycle cost of a shake roof may be high, and old shakes can’t be recycled. Most wood shakes are unrated by fire safety codes. Many use wipe or spray-on fire retardants, which offer less protection and are only effective for a few years. Some pressure-treated shakes are impregnated with fire retardant and meet national fire safety standards. Installing wood shakes is more complicated than roofing with composite shingles, and the quality of the finished roof depends on the experience of the contractor, as well as the caliber of the shakes used. The best shakes come from the heartwood of large, old cedar trees, which are difficult to find. Some contractors maintain that shakes made from the outer wood of smaller cedars, the usual source today, are less uniform, more subject to twisting and warping, and don’t last as long.

Concrete and Tile

Concrete tiles are made of extruded concrete that is colored. Traditional roofing tiles are made from clay. Concrete and clay tile roofing systems are durable, aesthetically appealing, and low in maintenance. They also provide energy savings and are environmentally friendly. Although material and installation costs are higher for concrete and clay tile roofs, when evaluated on a price-versus-performance basis, they may out-perform other roofing materials. Tile adorns the roofs of many historic buildings, as well as modern structures. In fact, because of its extreme durability, longevity and safety, roof tile is the most prevalent roofing material in the world. Tested over centuries, roof tile can successfully withstand the most extreme weather conditions including hail, high wind, earthquakes, scorching heat, and harsh freeze-thaw cycles. Concrete and clay roof tiles also have unconditional Class A fire ratings, which means that, when installed according to building code, roof tile is non-combustible and maintains that quality throughout its lifetime. In recent years, manufacturers have developed new water-shedding techniques and, for high-wind situations, new adhesives and mechanical fasteners. Because the ultimate longevity of a tile roof also depends on the quality of the sub-roof, roof tile manufacturers are also working to improve flashings and other aspects of the underlayment system. Under normal circumstances, properly installed tile roofs are virtually maintenance-free. Unlike other roofing materials, roof tiles actually become stronger over time. Because of roof tile’s superior quality and minimal maintenance requirements, most roof tile manufacturers offer warranties that range from 50 years to the lifetime of the structure.

Concrete and clay tile roofing systems are also energy-efficient, helping to maintain livable interior temperatures (in both cold and warm climates) at a lower cost than other roofing systems. Because of the thermal capacity of roof tiles and the ventilated air space that their placement on the roof surface creates, a tile roof can lower air-conditioning costs in hotter climates, and produce more constant temperatures in colder regions, which reduces potential ice accumulation. Tile roofing systems are made from naturally occurring materials and can be easily recycled into new tiles or other useful products. They are produced without the use of chemical preservatives, and do not deplete limited natural resources.


Single-ply membranes are flexible sheets of compounded synthetic materials that are manufactured in a factory. There are three types of membranes: thermosets, thermoplastics, and modified bitumens. These materials provide strength, flexibility, and long-lasting durability. The advantages of pre-fabricated sheets are the consistency of the product quality, the versatility in their attachment methods, and, therefore, their broader applicability. They are inherently flexible, used in a variety of attachment systems, and compounded for long-lasting durability and watertight integrity for years of roof life. Thermoset membranes are compounded from rubber polymers. The most commonly used polymer is EPDM (often referred to as “rubber roofing”). Thermoset membranes make successful roofing materials because they can withstand the potentially damaging effects of sunlight and most common chemicals generally found on roofs. The easiest way to identify a thermoset membrane is by its seams, which require the use of adhesive, either liquid or tape, to form a watertight seal at the overlaps. Thermoplastic membranes are based on plastic polymers. The most common thermoplastic is PVC (polyvinyl chloride) which has been made flexible through the inclusion of certain ingredients called plasticizers. Thermoplastic membranes are identified by seams that are formed using either heat or chemical welding. These seams are as strong or stronger than the membrane itself. Most thermoplastic membranes are manufactured to include a reinforcement layer, usually polyester or fiberglass, which provides increased strength and dimensional stability. Modified bitumen membranes are hybrids that incorporate the high-tech formulation and pre-fabrication advantages of single-ply with some of the traditional installation techniques used in built-up roofing. These materials are factory-fabricated layers of asphalt, “modified” using a rubber or plastic ingredient for increased flexibility, and combined with reinforcement for added strength and stability. There are two primary modifiers used today: APP (atactic polypropylene) and SBS (styrene butadiene styrene). The type of modifier used may determine the method of sheet installation. Some are mopped down using hot asphalt, and some use torches to melt the asphalt so that it flows onto the substrate. The seams are sealed by the same technique.

Are You at Risk?

If you aren’t sure whether your house is at risk from natural disasters, check with your local fire marshal, building official, city engineer, or planning and zoning administrator. They can tell you whether you are in a hazard area. Also, they usually can tell you how to protect yourself and your house and property from damage. It is never a bad idea to ask an InterNACHI inspector whether your roof is in need of repair during your next scheduled inspection. Protection can involve a variety of changes to your house and property which that can vary in complexity and cost. You may be able to make some types of changes yourself. But complicated or large-scale changes and those that affect the structure of your house or its electrical wiring and plumbing should be carried out only by a professional contractor licensed to work in your state, county or city. One example is fire protection, accomplished by replacing flammable roofing materials with fire-resistant materials. This is something that most homeowners would probably hire a contractor to do.
Replacing Your Roof

The age of your roof is usually the major factor in determining when to replace it. Most roofs last many years, if properly installed, and often can be repaired rather than replaced. An isolated leak usually can be repaired. The average life expectancy of a typical residential roof is 15 to 20 years. Water damage to a home’s interior or overhangs is commonly caused by leaks from a single weathered portion of the roof, poorly installed flashing, or from around chimneys and skylights. These problems do not necessarily mean you need a new roof.
Fire-Resistant Materials

Some roofing materials, including asphalt shingles, and especially wood shakes, are less resistant to fire than others. When wildfires and brush fires spread to houses, it is often because burning branches, leaves, and other debris buoyed by the heated air and carried by the wind fall onto roofs. If the roof of your house is covered with wood or asphalt shingles, you should consider replacing them with fire-resistant materials. You can replace your existing roofing materials with slate, terra cotta or other types of tile, or standing-seam metal roofing. Replacing roofing materials is difficult and dangerous work. Unless you are skilled in roofing and have all the necessary tools and equipment, you will probably want to hire a roofing contractor to do the work. Also, a roofing contractor can advise you on the relative advantages and disadvantages of various fire-resistant roofing materials.


Hiring a Licensed Contractor
One of the best ways to select a roofing contractor is to ask friends and relatives for recommendations. You may also contact a professional roofers association for referrals. Professional associations have stringent guidelines for their members to follow. The roofers association in your area will provide you with a list of available contractors. Follow these guidlines when selecting a contractor:
  • get three references and review their past work;
  • get at least three bids; 
  • get a written contract, and don’t sign anything until you completely understand the terms; 
  • pay 10% down or $1,000 whichever is less; 
  • don’t let payments get ahead of the work; 
  • don’t pay cash; 
  • don’t make final payment until you’re satisfied with the job; and 
  • don’t rush into repairs or be pressured into making an immediate decision.
You’ve Chosen the Contractor… What About the Contract?
Make sure everything is in writing. The contract is one of the best ways to prevent problems before you begin. The contract protects you and the contractor by including everything you have both agreed upon. Get all promises in writing and spell out exactly what the contractor will and will not do.
…and Permits?
Your contract should call for all work to be performed in accordance with all applicable building codes. The building codes set minimum safety standards for construction. Generally, a building permit is required whenever structural work is involved. The contractor should obtain all necessary building permits. If this is not specified in the contract, you may be held legally responsible for failure to obtain the required permits. The building department will inspect your roof when the project has reached a certain stage, and again when the roof is completed.
and Insurance?
Make sure the contractor carries workers’ compensation insurance and general liability insurance in case of accidents on the job. Ask to have copies of these policies for your job file. You should protect yourself from mechanics’ liens against your home in the event the contractor does not pay subcontractors or material suppliers. You may be able to protect yourself by having a “release of lien” clause in your contract. A release of lien clause requires the contractor, subcontractors and suppliers to furnish a “certificate of waiver of lien.” If you are financing your project, the bank or lending institution may require that the contractor, subcontractors and suppliers verify that they have been paid before releasing funds for subsequent phases of the project.

Rodent Inspection

By Bud Coburn

Rodents are a problem not just because they can destroy personal property and create problems with a home’s structure, but also because they can spread serious diseases to humans and their pets. Rodent-borne disease may be spread directly — by touching rodents or their Rat in a PVC pipeurine, feces or saliva — or indirectly — by coming into contact with fleas or other insects that have fed on an infected rodent host. Inspectors should use extreme caution and wear appropriate personal protective equipment when entering a home that is known to be infested with rodents.
Some diseases resulting from direct contact with mice and rats include:
  • hantavirus pulmonary syndrome;
  • hemorrhagic fever with renal; syndrome;
  • Lassa fever;
  • leptospirosis;
  • lymphocytic chorio-meningitis;
  • plague;
  • rat-bite fever;
  • salmonellosis;
  • South American arenaviruses; and
  • tularemia.
Some diseases resulting from indirect contact with mice and rats include:
  • babesiosis;
  • Colorado tick fever;
  • human granulocytic anaplasmosis;
  • lyme disease;
  • murine typhus;
  • scrub typhus;
  • rickettsialpox;
  • relapsing fever; and
  • Rocky Mountain spotted fever.

Rodents also pose a danger to the integrity of the structures they inhabit. They have strong teeth and they may chew through structures to gain access to food sources. The best method for preventing exposure to rodents is to prevent rodent infestation in the first place, according to the Centers for Disease Rodent trapControl (CDC) and the U.S. Environmental Protection Agency (EPA).

How can you tell that a home is infested?
Actual rodent sightings in the home are a good indicator that a severe infestation may be in progress.  Mild cases of infestation might not result in actual rodent sightings.
Indicators of an infestation are:
  • chewing or clawing sounds that come from inside or outside a home. Noises may even come from the roof, as tree-dwelling rodents may try to gain access to a home from above the living space;
  • stale smells coming from hidden areas;
  • evidence of structural damage that can provide entry points into the home;
  • evidence of gnawing and chewing on food packaging;
  • nesting material found in small piles, such as shredded paper, fabric or dried plant matter; and
  • rodent droppings anywhere in the home, especially near food packages in drawers and cupboards, and under the sink.
How can rodent infestation be prevented?
The following measures can be taken to eliminate rodents’ food sources, according to the CDC:
  • Keep food in thick plastic or metal containers with tight-fitting lids.
  • Clean up spilled food right away, and wash dishes and cooking utensils soon after use.
  • Keep outside cooking areas and grills clean.
  • Always put pet food away after use and do not leave pets’ food or water bowls out overnight.
  • Keep bird feeders away from the house.  Utilize squirrel guards to limit access to the feeder by squirrels and other rodents.
  • Use thick plastic or metal garbage cans with tight-fitting lids.
  • Keep compost bins as far away from the house as possible.
  • Dispose of trash and garbage on a frequent and regular basis, and eliminate clutter in and around the property to discourage nesting.
Mice can squeeze through a hole the size of a nickel, and rats can squeeze through a hole the size of a half dollar, according to the CDC. Consequently, smaller gaps may be filled cheaply and easily with steel wool and caulk may be used to seal it in place. Larger gaps and holes may be filled with lath screen or lath metal, cement, hardware cloth or metal sheeting.
Common places where gaps may be found inside the home are:
  • inside, under and behind kitchen cabinets, refrigerators and stoves;
  • inside closets near the floor’s corners;
  • around the fireplace;
  • around doors;
  • around plumbing pipes under sinks and washing machines;
  • around the piping for hot water heaters and furnaces;
  • around floor vents and dryer vents;
  • inside the attic;
  • in the basement or crawlspace;
  • near the basement and laundry room floor drains; and
  • between the floor and wall juncture.
Common places where gaps may be found outside the home are:
  • in the roof among the rafters, gables and eaves;
  • around windows;
  • around doors;
  • around the foundation;
  • near attic vents and crawlspace vents;
  • under doors; and
  • around holes for electrical, plumbing, cable and gas lines.
Any potential nesting sites outside the home should be eliminated. Elevate hay, woodpiles and garbage cans at least 1 foot off the ground. Move woodpiles far away from the house. Get rid of old trucks, cars and old tires that mice and rats could use as homes. Keep grass cut short, and keep shrubbery within 100 feet of the home well-trimmed.
What should be done if a house is found to be infested with rodents?
It is important to stay away from rodents, and to protect children and pets from direct and indirect contact if they are found in the home. Droppings should be handled only with extreme caution, even if they have dried. A face mask and gloves should be worn if handling and cleaning up these droppings because disturbing fecal particles may precipitate airborne contaminants. Affected areas should be sterilized after the droppings have been removed.All holes, cracks, and gaps in a home should be sealed to keep out rodents
In mild cases of infestation, homeowners may choose to eliminate the rodents themselves. They should make sure to take preventative measures while doing so.  To remove rodents, homeowners will need to use traps or rodenticides.
Some different types of traps include:
  • lethal traps, such as snap traps, that are designed to trap and kill rodents;
  • live traps, such as cage-type traps, that capture rodents alive and unharmed, requiring that the rodents then be released or killed; and
  • glue boards, which are low-cost devices that use sticky substances to trap rodents, requiring a further decision regarding disposal, since such traps are not lethal.
Traps should be set in any area where there is evidence of frequent rodent activity. Some rodents, particularly rats, are very cautious and several days may pass before they approach the traps. Other rodents, such as house mice and deer mice, are less cautious and may be trapped more quickly. Glue traps and live traps may scare mice that are caught live, causing them to urinate. This may increase a homeowner’s risk of being exposed to diseases, since the rodent urine may contain germs or disease-borne pathogens.

Rodenticides are products intended to kill rodents, and are typically sold as powders in bait and tracking form.  Some rodenticides include:

  • baits, which combine rodenticides with food to attract rodents.  They may be formulated as blocks or paste and may be enclosed in a bait station;
  • tracking powders, which are rodenticides combined with a powdery material.  The powder sticks to the rodents’ feet and fur and is swallowed when the animals groom themselves.  After consuming the chemical poison contained in the bait or tracking powder, the rodents die.  Some rodenticides (including tracking powders) may be legally applied only by certified pesticide applicators because they may pose a risk to human health.
The following measures should be observed when an infestation is being eliminated:
  • Traps and baits should be placed in areas where children and pets cannot reach them.
  • Products should be used according to the label’s directions and precautions.
  • Only traps that are appropriate to the type and size of the targeted rodent should be used.
  • Glue boards should be placed in dry, dust-free areas, as moisture and dust will reduce their effectiveness.

It is advisable to contact a professional exterminator to deal with more severe infestations, since rodents reproduce constantly and quickly.

In summary, rodent infestation poses a serious risk to human health, and extreme caution must be taken when eliminating the problem.


By Bud Coburn

Rockwool refers to a type of thermal insulation made from actual rocks and minerals. A wide range of products can be made from this Rockwool blanketmaterial because of its superior ability to block heat and sound. Rockwool insulation is commonly used in building construction, industrial plants, and in automotive applications.
The term “rockwool” is sometimes used interchangeably with “mineral wool,” although the latter term is, in fact, a larger category of thermal insulators that includes rockwool, slag wool and fiberglass.
Rockwool is produced naturally during volcanic eruptions when high winds flow upon lava streams of basalt or diabase. This was the case when, in the early 1900s, Hawaiian volcanologists found an unusual, wool-like rock fiber hanging from trees near Mount Kilauea, and it wasn’t long before the fiber’s exceptional qualities were discovered.

Today, this process is replicated in commercial furnaces where minerals and other raw materials are heated to roughly 2,910° F (1,600° C) and subjected to a current of steam or air. Oil is also added during production to decrease the formation of dust. More advanced techniques require rotating the molten rock at high speeds in a spinning wheel, resembling the way that cotton candy is made. Finished rockwool is a mass of fine intertwined fibers that are bound together with starch and used as loose fill or assembled into blankets (batts and rolls). The main producers of rockwool in the U.S. are located in North Carolina, Texas, Washington and Indiana.

Rockwool’s Performance as an Insulator

The individual fibers that compose rockwool insulation are good conductors of heat on their own, but sheets and rolls of this insulation are efficient at blocking the transfer of heat. They are often used to prevent the spread of fire in buildings, in light of their extremely high melting point of 1,800° F to 2,000° F. With an R-value of 3.10 to 4.0, rockwool can play a significant role in reducing energy consumption in homes and businesses. Problems sometimes arise because rockwool can retain a large amount of water, although gravity will allow it to drain, as long as it has a path to escape.Rockwool fiber

Common Applications

  • In loose-fill form, it can be used for insulating equipment, tanks, pipelines, ovens and furnaces.
  • It is used in the manufacture of acoustical ceiling tiles.
  • It is used as for residential, commercial and industrial insulation. Rockwool is very effective for use as insulation behind and around electrical boxes, wires and pipes. It can fill most wall cavities, leaving virtually no voids.
  • It is also used as spray-on fireproofing material.


While many man-made mineral fibers are considered dangerous to humans, the danger is limited mostly to biopersistant materials, such as special-purpose glass wools and refractory ceramic fibers. The more common types of rockwool used as insulation are considered by the International Agency for Research on Cancer to be “not classifiable as carcinogenic in humans.” Rockwool can cause skin irritation, although this condition is a temporary mechanical irritation, rather than a more serious chemical irritation. Regardless, it is always good practice for homeowners, inspectors and contractors to wear quality gloves and other personal protective equipment while handling rockwool, or any other insulation.
In summary, rockwool is a type of thermal insulation made from heated, naturally-occurring minerals. It is generally considered to be safe and effective.

Reverse Mortgages

By Bud Coburn

Reverse mortgages are a means to convert part of the equity in a home into cash without having to sell the home or take on additional monthly bills, as required by home equity loans and second mortgages. Reverse mortgages are among the fastest-growing financial products today, as many older Americans who own their homes outright are learning to use these particular loans for a variety of purposes, from financing home improvement projects or paying off a current mortgage, to healthcare expenses or supplemental income. Reverse mortgages are a way tap your home's equity without taking on extra monthly bills

In fact, the National Reverse Mortgage Lenders Association estimated in 2008 that there would be well over 200,000 such loans that year, up from just 157 in 1990. The reason for this increase is partly due to the enormous reservoir of potential funds in the form of equity ($4 trillion among seniors, in 2008), balanced against rising medical costs and daily living expenses.

What is a reverse mortgage?

A reverse mortgage is essentially what it sounds like:  instead of borrowing money from the bank to purchase a home, a homeowner borrows money against the equity of their current home. The amount available to the homeowner depends upon their age, how much their home is worth, and current interest rates. Reverse mortgages can pay out in one or more of the following three ways:

  • a single, lump sum of cash;
  • a regular, periodic payout; or
  • a credit line to be accessed whenever it is needed.

Also, reverse mortgages are offered in the following three forms:

  • Home Equity Conversion Mortgages (HECMs), which are insured by the U. S. Department of Housing and Urban Development (HUD). These generally provide larger loan advances at a lower total cost compared with other reverse mortgages. Approximately 90% of reverse mortgages are HECMs;
  • single-purpose reverse mortgages, which are offered by some state and local governmental agencies and nonprofit organizations. These are generally inexpensive, but they are not available in all areas, and they can be used only for one purpose specified by the lender; and
  • proprietary reverse mortgages, which are private loans that are backed by the companies that develop them.

What’s the difference between a reverse mortgage and a home equity loan?

While reverse mortgages and home equity loans, also known as a second mortgages, are both based on home equity, reverse mortgages are distinct in the following critical ways:

  • There are no income or credit requirements. These proofs that the borrower can repay the loan are unnecessary when requesting a reverse mortgage, as the proof is solely the tangible equity of the house itself. Thus, reverse mortgages are popular for senior citizens who are house-rich but income- or credit-poor.
  • There are no required monthly payments. Only when the borrower dies, sells the home or moves away does the money become due. Of course, borrowers are still required to pay real estate taxes, utilities and other expenses.
  • A reverse mortgage provides home security.  The lender cannot remove the homeowners from their properties, as is done in foreclosures, as long as they stay current with their property taxes, insurance, and home maintenance fees.
  • The homeowner cannot outlive their equity. The accrued principal and interest come due when the borrower either moves out of his or her home for longer than 12 months, sells it, or dies.
  • The reverse mortgage provides a “nursing home clause” that guarantees that if the borrower has to move into a nursing home or other medical facility, he or she has up to 12 months before the loan becomes due.
  • HECMs, which account for the majority of reverse mortgages, require applicants to meet with an independent counselor who will explain the loan’s costs, financial implications and alternatives. This requirement improves the chances that the borrower will make an informed decision.

However, reverse mortgages have the following inherent risks:

  • There are substantial upfront fees, such as closing costs (appraisal, title and escrow), origination fee and a servicing fee. These charges can be paid years later when the loan is due, however, resulting in no immediate burden to the borrower.
  • Eligibility for state and federal government assistance programs, such as Medicare, may be jeopardized because the money received from the reverse mortgage counts as income.
  • Once equity is withdrawn from the home, there will be less money to pass on to heirs once the home is sold and the loan is repaid.
  • The interest rate for reverse mortgage may be tied to a volatile financial index, as are FHA loans and traditional mortgages.


To be eligible for a reverse mortgage, you must:
  • be a homeowner 62 years of age or older;
  • own your home outright, or have a low mortgage balance that can be paid off at closing using proceeds from the reverse loan; and
  • live in the home. To receive an HECM, the homeowner must live in a one- to four-unit home with one unit occupied by the borrower.

Eligibility for HECM and other reverse mortgages might require that your home be in structurally good condition and free of major problems, such as termite damage and roof leaks. An InterNACHI inspector should be hired to check for these and other defects.

A word about misinformation…

Cash-strapped and uniformed seniors should be wary of brokers and advertisements that claim that reverse mortgages as tax-free. Make no mistake — reverse mortgages are loans that must eventually be repaid, with interest, which is essentially a lender-imposed “tax.” Recipients of FHA loans, for instance, are also free from government taxes on their loan, but they are “taxed” by the broker who lent them the money.

Reverse mortgages offer a particular set of cash-strapped seniors an alternative, but they are not right for everyone. Seniors should educate themselves about reverse mortgages and other loan products so they can avoid manipulation by predatory lenders. While counseling on the pros and cons of a reverse mortgage is a requirement for federally insured loans — which account for the majority of loans today — this is not always adequate, and the help of a trusted friend or relative may be needed.  Always be sure to read and understand every clause before you enter into a contract.

In summary, senior citizens who require extra income should consider reverse mortgages, as well as their alternatives.