Performance standards prescribe levels of acceptability or approved modes to be used in building construction -including roofs – as bases of comparison. Test standards prescribe test methods and, sometimes, minimum acceptable results. Rating standards establish measurement methods to ensure similar products can be compared on the same bases. Design standards are minimum criteria that are applied to particular aspects of building and/or roof system design. The standards organizations that maintain standards affecting the roofing industry include American Society for Testing and Materials (ASTM), Factory Mutual Research (FMR) and Underwriters Laboratories (UL). Performance standards help assure you that what you are purchasing conforms to an acceptable pre-established standard of performance for your application. They are not the law but can in some situations have a dramatic affect upon insurability and insurance rates.

Modified Bitumen membranes are thicker and the sheets installed farther apart than conventional BURs. The distance between the seams in an MB roof should be 33”. Many MB roofs have a granule surface similar to the granules on a roofing shingle. Asphalt flow should typically be observed at the seams of these membranes.

Single Ply membranes are comprised of two major types of membranes. EPDM rubber is the predominate type of single ply. Thermoplastic membranes are the other types of single ply membranes. All EPDM roofs installed within the past 15 years should be black in color. White or gray membranes are typically thermoplastic. The sheet sizes of single ply membranes range from smaller sheets which would be 5’ wide to some that can be 100’ wide. There are three ways to install these roofs and they include ballasted, fully adhered, and mechanically fastened. Ballasted is the easiest to identify since the ballast for these roofs should be approximately 2” in diameter. Mechanically fastened single ply membranes can be one of several types. Older roofs of this type may have a plastic knob or multiple patches over fasteners within the field of the membrane. These are both visible on top of the membrane. Most newer single plies have the fasteners in the seams. These roofs may billow up on a windy day and/or you can move the membrane with your foot in the center of the panels. Finally fully adhered membranes will be smooth surfaced. Many Single Ply membranes are installed using this method. These membranes are typically adhered over a mechanically fastened insulation so the insulation fasteners may be visible under them membrane but they will not penetrate the membrane.

Identification using these factors will assist you when discussing your roofing system with others. There are reasons why certain roofing systems may deviate from these descriptions but the majority of roofing systems conform and can be identified with these techniques.

What does this mean to you? If your building is in an urban environment you will soon (if you haven’t already) begin hearing about energy efficient roofs. In Chicago there is already a new Chicago Energy Code which includes requirements for newly installed roofs pertaining to reflectivity. The Indianapolis area may not be far behind. Some of the factors to consider will include the use of light colored coatings over roof membranes or the use of white membranes. This will present a new set of challenges for the performance of new roofing systems and design considerations to keep new roofing systems both cost competitive and performance oriented. The decision by a building owner to switch from proven technology to something new should not be made without proper study and evaluation. The early days of single ply membrane roofing in the United States should serve as a reminder that ALL new technology doesn’t always work.

Mold requires three elements to exist: 1) A moisture source 2) a warm humid environment 3) a food source. Molds and mildews take time to grow and spread since they are microscopic spores which develop into root hairs that expand when the proper environment for them to grow exists. Moisture is a key element in this environment and since moisture is frequently a common element with storm damage the question must be answered – What is the extent of the moisture contribution from the storm?

More typical causes of mold in buildings involve leaks in roofs, windows, walls and foundations in buildings. Improper ventilation is the second most common contributing factor to mold and mildew growth. Moisture introduction through other building components such as HVAC or plumbing units are other substantial contributing factors for moisture and mold in buildings.

Certainly the results of a severe storm can contribute to moisture in buildings but buildings themselves are typically the greatest source of moisture gain. Mold and mildew develop when moisture continues to enter without provisions and/or no attempts to remove it are/can be made.

Further information can also be found on the National Association of Mutual Insurance Companies website – www.moldupdate.com )

The temperature at which the air/water vapor mixture no longer retains its water vapor in the gaseous state is called the dew point temperature of the mixture. The ratio of the amount of water vapor in air compared to the maximum amount air can hold at a specific temperature is called the relative humidity. When air is absolutely dry, its relative humidity is 0 %. When an air mixture has reached its dew point temperature, its relative humidity is 100%; the higher the relative humidity, the greater water vapor content of the air at that temperature.

Each component of the air mixture is driven by the partial pressure of each component. Even though water vapor can move independently of air, when air is heated or cooled, the water vapor should be considered as part of the air-vapor mixture. If air is exposed to changing temperatures, the air will be driven from an area of higher partial pressures to an area of lower partial pressures. One of the components of air, water vapor, is also impacted by partial pressure. It is this natural phenomenon which moves water vapor though the air or any porous material.

Condensation has an impact on our daily lives and the buildings that we live and work in. This can be a significant factor in generation of mold growth but also results in saturation and deterioration of building materials – especially roofing systems.

As you hear the dew point or humidity reports this summer perhaps you will better understand how they impact your daily life. At least you can better understand why the outside of a cold beverage glass is wet this summer.

After a short period of less than a year in some cases, problems began occurring with corrosion of the fasteners and metals that were used in conjunction with these new preservatives. As a result new fasteners and precautions with metal contact began to surface in 2005. It has been clearly identified that the use of carbon steel, aluminum, and electroplated galvanizes steel fasteners and connectors should not be used in contact with these new wood preservatives. These components made up the majority of the fasteners and metals previously used with treated lumber!

New fasteners and metals now recommended for use with treated lumber include some but not all types of hot dipped galvanized fasteners and connectors. There are now specific ASTM standards which fasteners and metals must meet to be appropriate for use with treated lumber. Certain types of stainless steel fasteners are recommended for maximum corrosion resistance.

Care must now be taken when dealing with treated lumber in all types of construction projects. The first question should be is treated lumber really necessary? If so the type of wood treatment used should be verified and the type of fasteners and metal to be involved confirmed to assure that corrosion of the metal will not create a significant problem in the future.

For more information regarding roofing or leak analysis please give us a call at 1-877-770-8131.

Since building codes are the law, adherence to the building codes is not optional. Model building codes are codes developed on a “national” level to give specific guidance to construction methods. These national codes are then adopted by State code officials for their areas of responsibility. Local code bodies then adopt the State code and can add local requirements. Thus building codes are backwards from what many assume them to be. The local codes can supersede the State and National codes if local code officials desire more stringent regulation. Miami Dade is an example of a local area with stricter codes as would be codes in California. In these areas where hurricanes or earthquakes are more frequent the local codes more specifically address these requirements.

There have been three major national building codes from which states could base their codes upon. Consolidation of these three national codes (BOCA, ICBO, & SBCCI) is a welcome transition for those seeking to understand and or enforce codes in their areas.

A roofing system is comprised of a roof membrane, typically installed over some type of insulation or hard board. These insulations range from wooden roof decks, wood fiberboard, perlite, fiberglass, high density gypsum board, poly isocyanurate, or Styrofoam. The most prominent roof membranes include asphalt and cedar shake shingles, roofing tiles of various forms, slate, metal roofing, asphalt built up roofing, single ply membranes, sprayed polyurethane foam, and modified bitumen membranes. All of these membranes have different physical properties and their resistance to hail impact differs greatly. The roofing system includes all parts of the roofing system on top of the roof deck.

A roof assembly includes the roofing system and the structural roof deck assembly.

Bridging of older EPDM roofs is a prime example. The bridging issue is one that does not result in moisture entering the building until a seam is pulled loose or the EPDM is torn. This can take many years but when the failure occurs it can result in large amounts of water entering the building. Material manufacturers typically don’t pay for repairs of this condition since the building is not leaking so the condition continues until catastrophic failure occurs. This can take a longer period of time than the material manufacturer’s warranty covers. As a result, the costs to replace the damaged roof are higher plus there is the additional damage to the interior of the building.

A proactive approach involves roof inspections by an independent source to identify these problems while they are still minor repairs that can be fixed. This approach can prevent major replacement thus prolonging the useful service life of the roof.