Inspecting House Numbers

by Nick Gromicko and Kenton Shepard

Originally published at NACHI.ORG

house numbers inspection

House numbers should be clear enough so that police, the fire department, paramedics, etc., can quickly locate properties in an emergency. House numbers are often the only way that first-responders can identify their intended destinations. A number of jurisdictions have begun enforcing laws through strict fines for homeowners who do not comply with laws that impose requirements for house numbers.

Local Regulations

Many municipalities and counties have implemented ordinances requiring property owners to standardize the display of house numbers on buildings. The city of St. Martinville, Louisiana, for instance, is considering requiring its citizens to display street numbers in block numbering that is at least 4 inches tall and is either illuminated at night or has a reflective finish. If the ordinance is passed, the city will fine offenders $200, plus hundreds more in court fees. In Florida, the cities of Clearwater, Largo and St. Petersburg have begun enforcing their own municipal codes that regulate the visibility of house numbers, imposing fines for violators.

House numbers is normally considered as part of our new construction inspection.

Common Requirements

In order for house numbers to be visible from the street, InterNACHI advises that they should:

  • be large. Jurisdictions that regulate the size of street numbers generally require that them to be 3 to 6 inches tall. Many jurisdictions require that the numbers be of a certain thickness, such as 1/2-inch, as required by New York City;
  • be of a color that contrasts with their background. Reflective numbers are usually helpful because they are easier to see at night than numbers that are not reflective;
  • not be obscured by any trees, shrubs, or other permanent objects;
  • face the street that is named in the house’s address. It does emergency workers no good if the house number faces a different street than the one the workers are traveling on;
  • be clearly displayed at the driveway entrance if the house is not visible from the road.
According to 6.5.12 of the International Standard for Inspecting Commercial Properties, inspectors should:

Inspect the address or street number to determine that it is visible from the street with numbers in contrast to their background.

Future Adjustments

Even if a house number is currently adequate, it might need adjustment in the future. The following are common reasons for future adjustment:

  • The numbers assigned to houses by the municipality occasionally change, and homeowners must adjust their house numbers accordingly.
  • The trees or shrubs in front of the house have grown so much that the number is no longer visible. House numbers installed in the winter may be visible during that season but become blocked by budding vegetation by spring or summer.
  • House numbers will require maintenance when they get dirty. Numbers may not be reflective or contrasting if they are covered in mud.  
  • Snow piles created by snow plows during the winter may be high enough to cover the number. If this happens, the number should be raised so this situation does not repeat.

In summary, house numbers serve a critical function for emergency personnel and should be clearly displayed.

Don’t forget to check out our last blog article about ice dams.


Ice Dams Inspection

by Nick Gromicko

Originally published at NACHI.ORG

ice dams inspection

An ice dam is a ridge of ice that forms at the edge of a roof and prevents melting snow from draining. As water backs up behind the dam, it can leak through the roof and cause damage to walls, ceilings, insulation and other areas.

How do ice dams form?

Ice dams are formed by an interaction between snow cover, outside temperatures, and heat lost through the roof. Specifically, there must be snow on the roof, warm  portions of the upper roof (warmer than 32° F), and cold portions of the lower roof (at freezing or below). Melted snow from the warmer areas will refreeze when it flows down to the colder portions, forming an ice dam.

Although the primary contributor to snow melting is heat loss from the building’s interior, solar radiation can also provide sufficient heat to melt snow on a roof. For example, in southern Canada, enough sunlight can be transmitted through 6 inches (150 mm) of snow cover on a clear and sunny day to cause melting at the roof’s surface even when the outside temperature is 14° F (-10° C), with an attic temperature of 23° F (-5° C).

Gutters do not cause ice dams to form, contrary to popular belief. Gutters do, however, help concentrate ice from the dam in a vulnerable area, where parts of the house can peel away under the weight of the ice and come crashing to the ground.

Problems Associated with Ice Dams

Ice dams are problematic because they force water to leak from the roof into the building envelope. This may lead to:

  • rotted roof decking, exterior and interior walls, and framing;
  • respiratory illnesses (allergies, asthma, etc.) caused by mold growth;
  • reduced effectiveness of insulation. Wet insulation doesn’t work well, and chronically wet insulation will not decompress even when it dries. Without working insulation, even more heat will escape to the roof where more snow will melt, causing more ice dams which, in turn, will lead to leaks; and
  • peeling paint. Water from the leak will infiltrate wall cavities and cause paint to peel and blister. This may happen long after the ice dam has melted and thus not appear directly related to the ice dam.


  • Keep the entire roof cold. This can be accomplished by implementing the following measures:
    • Install a metal roof. Ice formations may occur on metal roofs, but the design of the roof will not allow the melting water to penetrate the roof’s surface. Also, snow and ice are more likely to slide off of a smooth, metal surface than asphalt shingles.
    • Seal all air leaks in the attic floor, such as those surrounding wire and plumbing penetrations, attic hatches, and ceiling light fixtures leading to the attic from the living space below.
    • Increase the thickness of insulation on the attic floor, ductwork, and chimneys that pass through the attic.
  • Move or elevate exhaust systems that terminate just above the roof, where they are likely to melt snow.
  • A minimum of 3″ air space is recommended between the top of insulation and roof sheathing in sloped ceilings.
  • Remove snow from the roof. This can be accomplished safely using a roof rake from the ground. Be careful not to harm roofing materials or to dislodge dangerous icicles.
  • Create channels in the ice by hosing it with warm water. Because this process intentionally adds water to the roof, this should be done only in emergencies where a great deal of water is already flowing through the roof, and when temperatures are warm enough that the hose water can drain before it freezes.

Prevention and Removal Methods to Avoid

  • electric heat cables. These rarely work, they require effort to install, they use electricity, and they can make shingles brittle.
  • manual removal of the ice dam using shovels, hammers, ice picks, rakes, or whatever destructive items can be found in the shed. The roof can be easily damaged by these efforts, as can the homeowner, when they slip off of the icy roof.
In summary, ice dams are caused by inadequate attic insulation, but homeowners can take certain preventative measures to ensure that they are rare.
We invite you to check out our last blog article about rubber flooring.

Rubber Flooring Inspection

by Nick Gromicko

Originally published at NACHI.ORG

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.

Rubber flooring is normally considered as part of our new construction inspection.

A Brief History of Rubber

interlocking 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.speckled rubber tiles

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… Some 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.

Check out our last article about roof underlayment.

Roof Underlayment Inspection

by Nick Gromicko and Kenton Shepard

Originally published at NACHI.ORG

When a roofer first walks onto a job, unless he’s tearing off an old roof-covering material, he’s faced with a bare roof deck. The first component to be installed on the roof is underlayment.

Underlayments are manufactured with different properties designed to meet the needs of homes in different climate zones. An underlayment that works well under metal roofing in a hot, humid place like New Orleans, Louisiana, may not work well beneath wood shakes in a cold, dry climate like Jackson, Wyoming.

The different types of roof-covering materials may also have specific underlayment requirements.

As an inspector, you will not be responsible for confirming that the proper type of underlayment was used, but if you see problems with the roof, understanding the basic properties and general installation requirements of underlayment may give you a clue as to the source of the problem.

Although underlayment is typically required in new construction by building codes, in the past, roof-covering material manufacturers haven’t always required it on slopes of 4:12 and steeper.


Moisture Barrier

Most roof-covering materials are not waterproof, but water-resistant, and are designed to be installed over a waterproof or water-resistant membrane of some type. “Underlayment” is the general term used to describe these membranes.

Even though the underlayment is the first material to be installed on the roof deck, the roof-covering material – the shingles, tiles, metal or slate – is the primary barrier against roof leakage. Underlayment is a secondary barrier.

Water-resistant underlayment may allow the passage of moisture vapor, but will prevent the passage of water in its liquid form. Waterproof underlayment will prevent the passage of both liquid water and water vapor.

Waterproof underlayment is typically used on parts of the roof that are more likely to leak or suffer moisture intrusion. This includes penetrations in areas where roof-covering materials change or end, and low-slope sections of roof. It’s not unusual to use combinations of underlayment on a home’s roof.

The permeability of underlayment is the extent to which it allows the passage of water vapor. Although all underlayments are designed to prevent the passage of moisture in its liquid form, they can have different levels of resistance to the passage of water vapor.

Underlayment permeability ratings are provided by the manufacturers, and are less important in roof underlayment than they are in housewrap. Underlayments with a perm rating of 1 or less are moisture barriers. Underlayments rated above 1 are moisture retarders.

Temporary Protection

Underlayment provides temporary protection of the building interior and the roof deck before the roof-covering material is installed.

Ideally, the roof-covering material would be installed as soon as possible, but in the real world, the roof may be protected by only the underlayment for days, weeks, or sometimes months.

Protecting the building interior is especially important when an old roof-covering material is being replaced and the home interior is finished. During that time, the underlayment may be under attack from weather elements such high winds, UV radiation, and precipitation. It also needs to resist the wear and tear that occurs when the roof-covering material is being installed.

Preventing Chemical Degradation

Underlayment also provides a layer of separation between the roof sheathing and the roof-covering material.

Newer homes use plywood or an engineered panel called oriented strand board (OSB) for roof sheathing

For many years, pine and fir boards were used as sheathing, and many older homes still have these boards in place. Resin pockets in these boards can react chemically with some roof-covering materials, such as asphalt shingles. In these situations, missing underlayment can cause accelerated deterioration and premature failure of the roof-covering material.

Fire Resistance

Underlayment materials are available for wood roofs which increase their resistance to fire. In fact, without special underlayment, wood shakes and shingles cannot achieve a Class A fire rating, which is the highest available.


A number of factors can affect the performance of underlayment and determine which types are appropriate:

Climate Types

For purposes of determining optimum roofing material, depending on location, climates in North America can be separated into two basic categories:

  • hot or cold dry climates and;
  • hot or cold humid climates.

Hot and dry climates will affect bituminous underlayment by accelerating the loss of volatiles.

In humid climates, older felt underlayment will absorb more moisture which, in turn, can be absorbed by the substrate, causing it to expand. In cold climates, underlayment will become brittle and more easily damaged by footfall and impact.

Each of these climate types should have underlayment installed which has performance characteristics compatible with that particular climate.

Roof Design

Some designs shed runoff quickly. Some have design features which may actually trap runoff and expose the underlayment to more moisture.

Roof-Covering Material

Manufacturers produce underlayment of different types for use with the different types of roof-covering materials. The use of underlayments that are not compatible with the roof-covering material with which they’re installed can cause problems.

Roof-covering materials in poor condition which expose underlayment to weather, especially to UV radiation from sunlight, can accelerate deterioration.

Missing Underlayment

Although underlayment is typically required in new construction by building codes, in the past, some manufacturers have not required it on roofs of 4:12 and steeper. Unless you know for certain that the roof-covering material on the home you’re inspecting required underlayment, you should refrain from calling missing underlayment a defective installation.

Determining whether underlayment was required means finding the manufacturer’s installation instructions for that particular roof-covering material, and also finding out what jurisdictional requirements were in place at the time the home was built.

Since this research falls well beyond InterNACHI’s Standards of Practice, you might better serve your client by making them aware of the steps needed to confirm proper installation, and recommending a qualified roofing contractor.


Installation methods vary with the pitch of the roof, with the requirements of both the underlayment and roof-covering material manufacturers, and with jurisdictional requirements.

headwall flashing condition

At headlaps and sidelaps, all underlayments should extend up the wall for at least several inches.

Fastening Methods

Unless the underlayment is self-adhering, it’s attached to the roof with fasteners, which are a disadvantage because they make holes in the underlayment.

One of two fasteners is usually used.  Staples are the most common, but in high-wind areas and with synthetics, underlayment is often fastened with plastic caps.

plastic caps

“Plastic caps” is the industry term for nails that come with plastic gaskets attached. They are typically used for conditions where wind damage to underlayment is a possibility.  They also help seal against moisture intrusion.

In high-wind areas, it’s not unusual for roof-covering materials to be blown off while the underlayment remains in place. In these situations, the remaining underlayment can make a big difference in limiting interior water damage. Underlayment fastened with plastic caps instead of staples is a lot more likely to remain in place.

Ice Barriers

In areas where there is a history of ice forming along the eaves, causing melt-water to back up under the shingles (or ice dams), the ice barrier underlayment should be installed at the roof edge. An ice barrier is typically a self-sealing, self-adhering waterproof underlayment.

ice barrier

The International Residential Code (IRC) is the residential building code most widely adopted in the U.S. According to the IRC, the ice barrier should extend from the lower roof edge to a point at least 24 inches in from the outside of the exterior wall, measured level.

All other roofing industry organizations specify that the 24 inches be measured from the inside of the exterior wall.

On roofs with steep pitches, this may require up to four courses of underlayment. Depending on the roof-covering material and the installation method, you may not be able to confirm proper ice barrier installation. Ice barrier requirements are the same no matter what roof-covering material is installed.

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.

We invite you to check out our last blog article about ceiling fan.

Inspecting Ceiling Fan

by Nick Gromicko

Originally published at NACHI.ORG

A fan attached to a room’s ceiling is known as a ceiling fan. Like other fans, it is used to provide comfort for building occupants by circulating air within a room.

Fun Facts About Ceiling Fans

  • An adult human cannot be decapitated by a ceiling fan, according to the TV show “MythBusters.”  A powerful, industrial-strength fan might be able to damage a skull or slice a person’s neck, however.
  • Ceiling fans were first used in the United States in the 1860s. They were powered by a system of belts driven by a stream of running water.
  • Unlike air conditioners, fans do not actually cool the air, which is why they merely waste electricity when they circulate air in an unoccupied room.

Ceiling Fan Components

A ceiling fan is comprised of the following parts:ceiling fan

  • electric motor:  varies with the size of the fan and its application;
  • blades:  typically, two to six spinning, precision-weighted blades made from metal, wood or plastic; industrial fans typically have three blades, while residential models have four or five;
  • blade irons:  connect the blades to the motor;
  • safety cable: on heavy fans, these are required to hold the fan in place in case the support housing fails;
  • flywheel:  connects the blade irons to the motor;
  • ceiling mount:  designs include ball-in-socket and J-hook;
  • downrod:  used where ceiling fans are suspended from high ceilings;
  • motor housing:  protects the fan motor from dust and its surroundings; may also be decorative; and
  • lamps: may be installed above, below or inside the motor housing.

Common Fan Defects

  • The fan falls. A ceiling fan that breaks free from its ceiling mount can be deadly. Fans must be supported by an electrical junction box listed for that use, according to the National Electric Code, and a fan brace box will need to be installed. While a particular junction box might support a fully assembled fan, during operation, it will exert additional forces (notably, torsion) that can cause the support to fail. Homeowners often overlook this distinction by carelessly replacing light fixtures with ceiling fans without upgrading the junction box, which should clearly state whether it’s rated to hold a ceiling fan.
  • The fan wobbles. This is a common and distracting defect that is usually caused when fan blades are misaligned from one another. Specific problems stem from minute differences in the size or weight of individual blades, warping, bent blade irons, or blades or blade irons that are not screwed in tightly enough. The ceiling mount may also be loose. Wobbling is not caused by the ceiling or the particular way that the fan was mounted. Wobbling will not cause the fan to fall, and there have been no such reports. Wobbling can, however, cause light fixture covers or shades to loosen and potentially fall. These items should be securely attached, with all screws tightly set in place. An easy way to tell if the blades are not on the same plane is to hold a yardstick or ruler against the ceiling and measure the distance that the tip of each blade is from the ceiling by manually pushing the blades. A homeowner can carefully bend the misaligned blade back into place. Blades can also be corrected in this way if measurement reveals that they are not equidistant from one another. 
  • There is inadequate floor-to-ceiling blade clearance. No part of the fan blades of a residential ceiling fan (usually having four or more blades) should be closer than 7 feet from the floor in order to prevent inadvertent contact with the blades. Downward air movement is maximized when the fan blades are around 8 or 9 feet from the floor. For high ceilings, the fan may be hung to a desired height. Low-profile fan models are available for ceilings that are lower than 8 feet from the floor. Also, fan blades should be at least 18 inches from walls. For commercial ceiling fans (usually having three blades), no part of the fan blades should be closer than 10 feet from the floor in order to prevent inadvertent contact with the blades.  Underwriters Laboratories UL 507 Section 70.2.1 says:

    “The blades of a ceiling-suspended fan shall be located at least 3.05 m (10 feet) above the floor when the fan is installed as intended.”

Underwriters Laboratories makes exceptions if the fan blade edges are thick and the fan is turning slowly.
  • Blades are turning in the wrong direction. In the winter months, the leading edge of the fan’s blades should be lower than the trailing edge in order to produce a gentle updraft, which forces warm air near the ceiling down into the occupied space below. In the summer, the leading edge of the fan’s blades should be higher as the fan spins counter-clockwise to cool occupants with a wind-chill effect. On most models, the fan direction can be reversed with an electric switch located on the outside of the metal housing, but the same effect can be achieved on other models by unscrewing and remounting the fan blades.
  • An indoor fan is not designed for exterior use. Ordinary indoor ceiling fans are unsafe to use outdoors or in humid environments, such as bathrooms.  They will wear out quickly. Fans that are rated “damp” are safe for humid environments, but they, too, should never be used where they might come into contact with liquid water. Only fans that are rated “wet” are safe for such use, as they incorporate features such as all-weather, UV-resistant blades, sealed motors, rust-resistant housing, and stainless steel hardware.
In summary, properly installed and maintained ceiling fans can inexpensively cool or warm building occupants.
Don’t forget to check out our last blog article about water damage in your home.

Preventing Water Damage in your Home

Originally published at NACHI.ORG

Water may be essential to life, but, as a destructive force, water can diminish the value of your home or building. Homes as well as commercial buildings can suffer water damage that results in increased maintenance costs, a decrease in the value of the property, lowered productivity, and potential liability associated with a decline in indoor air quality. The best way to protect against this potential loss is to ensure that the building components which enclose the structure, known as the building envelope, are water-resistant. Also, you will want to ensure that manufacturing processes, if present, do not allow excess water to accumulate. Finally, make sure that the plumbing and ventilation systems, which can be quite complicated in buildings, operate efficiently and are well-maintained. This article provides some basic steps for identifying and eliminating potentially damaging excess moisture.

Identify and Repair All Leaks and Cracks

The following are common building-related sources of water intrusion:

  • windows and doors: Check for leaks around your windows, storefront systems and doors.
  • roof: Improper drainage systems and roof sloping reduce roof life and become a primary source of moisture intrusion. Leaks are also common around vents for exhaust or plumbing, rooftop air-conditioning units, or other specialized equipment.
  • foundation and exterior walls: Seal any cracks and holes in exterior walls, joints and foundations. These often develop as a naturally occurring byproduct of differential soil settlement.
  • plumbing: Check for leaking plumbing fixtures, dripping pipes (including fire sprinkler systems), clogged drains (both interior and exterior), defective water drainage systems and damaged manufacturing equipment.
  • ventilation, heating and air conditioning (HVAC) systems: Numerous types, some very sophisticated, are a crucial component to maintaining a healthy, comfortable work environment. They are comprised of a number of components (including chilled water piping and condensation drains) that can directly contribute to excessive moisture in the work environment. In addition, in humid climates, one of the functions of the system is to reduce the ambient air moisture level (relative humidity) throughout the building. An improperly operating HVAC system will not perform this function.

Prevent Water Intrusion Through Good Inspection and Maintenance Programs

Hire a qualified InterNACHI inspector to perform an inspection of the following elements of your building to ensure that they remain in good condition:
  • flashings and sealants: Flashing, which is typically a thin metal strip found around doors, windows and roofs, are designed to prevent water intrusion in spaces where two building materials come together. Sealants and caulking are specifically applied to prevent moisture intrusion at building joints. Both must be maintained and in good condition.
  • vents: All vents should have appropriate hoods, exhaust to the exterior, and be in good working order.
  • Review the use of manufacturing equipment that may include water for processing or cooling. Ensure wastewater drains adequately away, with no spillage. Check for condensation around hot or cold materials or heat-transfer equipment.
  • HVAC systems are much more complicated in commercial buildings. Check for leakage in supply and return water lines, pumps, air handlers and other components. Drain lines should be clean and clear of obstructions. Ductwork should be insulated to prevent condensation on exterior surfaces.
  • humidity: Except in specialized facilities, the relative humidity in your building should be between 30% and 50%. Condensation on windows, wet stains on walls and ceilings, and musty smells are signs that relative humidity may be high. If you are concerned about the humidity level in your building, consult with a mechanical engineer, contractor or air-conditioning repair company to determine if your HVAC system is properly sized and in good working order. A mechanical engineer should be consulted when renovations to interior spaces take place.
  • moist areas: Regularly clean off, then dry all surfaces where moisture frequently collects.
  • expansion joints: Expansion joints are materials between bricks, pipes and other building materials that absorb movement. If expansion joints are not in good condition, water intrusion can occur.
Protection From Water Damage
  • interior finish materials: Replace drywall, plaster, carpet and stained or water-damaged ceiling tiles. These are not only good evidence of a moisture intrusion problem, but can lead to deterioration of the work environment, if they remain over time.
  • exterior walls: Exterior walls are generally comprised of a number of materials combined into a wall assembly. When properly designed and constructed, the assembly is the first line of defense between water and the interior of your building. It is essential that they be maintained properly (including regular refinishing and/or resealing with the correct materials).
  • storage areas: Storage areas should be kept clean.  Allow air to circulate to prevent potential moisture accumulation.

Act Quickly if  Water Intrusion Occurs

Label shut-off valves so that the water supply can be easily closed in the event of a plumbing leak. If water intrusion does occur, you can minimize the damage by addressing the problem quickly and thoroughly. Immediately remove standing water and all moist materials, and consult with a building professional. Should your building become damaged by a catastrophic event, such as fire, flood or storm, take appropriate action to prevent further water damage, once it is safe to do so. This may include boarding up damaged windows, covering a damaged roof with plastic sheeting, and/or removing wet materials and supplies. Fast action on your part will help minimize the time and expense for repairs, resulting in a faster recovery.

We invite you to check out our last blog article about attic insulation.

Installing Attic Insulation

by Nick Gromicko and Barry Fowler

Originally published at NACHI.ORG

According to the EnergyStar™ Program, heating and cooling costs can be slashed by up to 20% per year by properly sealing and insulating the home. Insulating the attic should be a top priority for preventing heat loss because as heat rises, a critical amount of heat loss from the living areas of the home occurs through an unfinished attic.  During the summer months, heat trapped in the attic can reduce a home’s ability to keep cool, forcing occupants to further tax the home’s cooling system.

The aim should be to insulate the living space of the house while allowing the roof to remain the same temperature as the outside. This prevents cold outside air from traveling through the attic and into the living area of the home. In order to accomplish this, an adequate venting system must be in place to vent the roof by allowing air flow to enter through soffit-intake vents and out through ridge vents, gable vents or louver vents.

ridge vent

If there is currently a floor in the attic, it will be necessary to pull up pieces of the floor to install the insulation. In this case, it will be easier to use a blower and loose-fill insulation to effectively fill the spaces between the joists. If you choose to go with blown-in insulation, you can usually get free use of a blower when you purchase a certain amount of insulation.

When installing fiberglass insulation, make sure that you wear personal protective equipment, including a hat, gloves, and a face mask, as stray fiberglass material can be inhaled and cause irritation to the lungs, eyes and exposed skin.

Before you begin actually installing the insulation, there is some important preparation involved in order to ensure that the insulation is applied properly to prevent hazards and to achieve maximum effectiveness.

Step 1: Install Roof Baffles

In order to maintain the free flow of outside air, it is recommended that polystyrene or plastic roof baffles are installed where the joists meet the rafters. These can be stapled into place. 

attic eave

Step 2: Place Baffles Around Electrical Fixtures

Next, place baffles around any electrical fixtures (lights, receptacles, etc.), since these may become hot while in use. Hold the baffles in place by cross-sectioning the rafters with 2x4s placed at a 3-inch clearance around the fixture.  Cut the polystyrene board to fit around the fixture and inside the wood square you have just created.

Step 3: Install a Vapor Barrier

If you are installing insulation with a vapor barrier, make sure it faces the interior of the house. Another option for a vapor barrier is to take sheets of plastic and lay them between the ceiling joists.  Then, using a staple gun, tack them to the sides of the joists.

Step 4:  Apply the Insulation

Begin by cutting long strips of fiberglass to measure, and lay them in between the joists. Do not bunch or compress the material; this will reduce the insulative effect.

If you are not planning to put in an attic floor, a second layer of insulation may be laid at 90º to the first layer. Do not lay in a second moisture barrier, as moisture could potentially be trapped between the two layers. This second layer of insulation will make it easier to obtain the recommended R-value. In colder climates, an R-value of 49 is recommended for adequate attic insulation. In warmer climates, an R-value of 30 is recommended. Fiberglass insulation has an R-value of roughly 3 per inch of thickness; cellulose  has an R-value of roughly 4 per inch, but it doesn’t retain its R-value rating as well as fiberglass.


If an attic floor is in place, it will be easier to use a blower to insert cellulose insulation into the spaces. The best way to achieve this is to carefully select pieces of the floor and remove them in such a manner that you will have access to all of the spaces in between the joists. Run the blower hose up into the attic. A helper may be needed to control the blower. Blow the insulation into the spaces between the joists, taking care not to blow insulation near electrical fixtures. Replace any flooring pieces that were removed.

Loose-fill insulation, either fiberglass or cellulose, is also a good option in cases where there is no attic floor. In such circumstances, you won’t need a blower, and can simply place the insulation between the joists by hand. You may also wish to even out the spread with a notched leveler.


When inspecting an attic, ensuring that there is a free flow of outside air from the soffits to the roof vents is key to a well-functioning insulation system. The lack of adequate ventilation in insulated attics is a common defect. When inspecting the attic, look behind the baffles to see if there is any misplaced insulation obstructing the natural air flow, and check the roof vents to make sure that outside air is exhausting properly. Check for a moisture barrier under the insulation.  Also, look for spots where the insulation is compacted; it may need to be fluffed out.  In the case of loose-fill insulation, check for any thinly spread areas that may need topping up. Finally, look for dirty spots in the insulation where incoming air is admitting dust into the material.

Don’t forget to check out our last blog article about ICFs and termites.