Q: What is ANSI?
A: The American National Standard Institute (ANSI) is a non-profit organization that administers and coordinates a voluntary standardization system.
Q: What is SPRI?
A: The Single-Ply Roofing Industry (SPRI) is a sheet membrane and component supplier to the commercial roofing industry. SPRI has worked with the roofing industry to develop consensus industry standards.
Q: What is FM Global?
A: Factory Mutual Global (FM) provides commercial and industrial property insurance and engineering-driven risk management solutions.
Q: What are ICC and IBC?
A: The International Code Council (ICC) is a non-profit organization that works to develop a single set of comprehensive and coordinated national model construction codes. The International Building Code (IBC) provides a consensus standard for construction codes.
Q: How and when did all these organizations get involved in setting roofing industry standards?
A: Prior to 1980 there were no roofing edge standards by which manufacturers could hold themselves to. FM then created a system of standards and approvals to use on FM insured properties. The design community adopted this because there were no other available standards at the time.
In 1998, SPRI developed a series of three tests for judging the quality and durability of fascia and coping. These tests result in ES-1 approval.
In 2003, the IBC wrote the ES-1 guidelines into their updated code. The majority of states and municipalities have adopted the 2003 IBC or a subsequent version, making ES-1 compliance crucial.
Q: How can I find code-compliant products?
A: Metal-Era has developed an easy-to-use ANSI/SPRI/FM 4435/ES-1 calculator. Enter a few basic facts about your building project, such as building height and location, and receive the basic wind speed, needed design pressure, and Metal-Era products which meet the design pressure.
Q: What does the IBC require of roof edge systems?
A: The 2007 IBC, §1504.5: "Edge securement for low-slope roofs. Low-slope membrane roof system metal edge securement, except gutters, shall be designed and installed for wind loads in accordance with Chapter 16 and tested for resistance in accordance with ANSI/SPRI/FM 4435/ES-1, except the basic wind speed shall be determined from Figure 1609."
The ANSI/SPRI/FM 4435/ES-1 document can be downloaded in its entirety for free from SPRI.
Q: Why has Metal-Era become involved in ES-1 testing? Which Metal-Era product lines have been tested?
A: Metal-Era’s commitment to long-lasting, quality products has made it vital that we ES-1 test all product lines. The testing provides customers the peace of mind to know they are not liable for a building code violation. Specifically, the following product lines have been ES-1 tested: Anchor-Tite, Perma-Tite, Systems 200, 300, 400 and 500 fascias, Anchor-Tite coping, Perma-Tite coping, Edge Systems One coping, and Metal-Era's private label partners’ (Carlisle, FiberTite, Firestone, GenFlex, Johns Manville, Koppers, Sika Sarnafil, Stevens, US Ply and Versico) full system warranty product lines. If you have a specific building project, you may use Metal-Era's ANSI/SPRI/FM 4435/ES-1 calculator. It quickly calculates the basic wind speed, the needed design pressure, and Metal-Era products which meet the design pressure.
Q: What are the benefits of proper ventilation?
- Extends the life of shingled roofs by minimizing the temperature differential between attic air and outside air, keeping the roof system cool during the hot summer months and preventing premature deterioration (less shingle replacement).
- Extends the life of metal roofs systems by preventing moisture from condensation that develops on the underside of the roof, ultimately causing rust and other structural problems.
- Prevents ice damming caused when the heat from inside the building and the sun melts the snow at the ridge. This causes water to run to the eaves and refreeze, a process that is repeated and eventually causes ice dams.
- Provides energy savings in the summertime by cooling the roof sheathing, preventing premature roof deterioration, premature roof replacement, and increased servicing of cooling units due to their excessive use. It prevents heat build-up in unvented systems which radiates downward and increases the demand on cooling systems.
- Prevents the interaction between hot and cold air which causes moisture from condensation (which in turn causes soaked insulation, corrosion, and water infiltration).
Q: How do thermal effects impact ventilation?
A: Warm air rises and cool air descends, therefore, cool air will naturally enter the system through lower eave vents and warm air will naturally exhaust through high ridge vents. A well circulated and balanced system takes advantage of this natural thermal effect.
Q: How does wind impact ventilation?
A: Wind speed as it moves against and over a building is key rather than the wind’s velocity. This creates high and low pressure zones (Bernoulli’s Principle). High pressures force air into the attic at the eave, while ridge vents create a baffle, causing low pressure to draw air from the ridge and prevent rain and snow from entering the attic.
Q: What is NFA?
A: Net free area (NFA) is the portion of the opening in the vent that actually ventilates; the total unobstructed area through which air can enter or exhaust. To calculate the needed NFA for your attic system, use our Attic Ventilation Calculator.
Q: What challenges are typical in venting?
- Larger structures
- Longer runs (eave and ridge)
- Larger surface area of the roof
- Lower pitches
- Larger heating and cooling systems, often placed in the attic
Q: What attic ventilation recommendations do you suggest?
A: Install vents with a balance system of net free vent area. Take into consideration the stack effect, air movement caused by wind and by temperature differences. As a requirement, for every 1” of exhaust air have greater than or equal intake and ensure that you have a balanced system.
Q: What ventilation product recommendations do you suggest?
A: Ventilation is only as good as the amount of airflow allowed in and out of the system. Most products on the market are designed for residential homes which require lower NFA ratings, which are inadequate for large, commercial roof systems. Most of these products provide inadequate ventilation after a 30’ run and most products provide inadequate ventilation after 75’ widths. Make sure that the products you select will provide proper ventilation for longer runs and widths. To help determine the amount of airflow required in your ventilation system, use our Nailbase Ventilation Calculator or our Attic Ventilation Calculator for attic ventilated systems.
Q: What are the problems associated with ice damming?
A: Ice damming can cause damage to roof coverings, fascia and gutters. Structural damage can occur as a result of the weight from the ice and water pooling inside the dam infiltrating under the shingles, damaging or destroying the shingles. The insulation can absorb water that has pooled from openings caused by ice dams, which causes the R-value to drop and creates an environment for mold, mildew, spores and fungi which can cause health problems.
Q: How can I guard against ice dams?
A: A proper defense against ice dams is critical. Metal-Era suggests utilizing:
- Proper insulation / adequate R-value
- Uses a waterproofing shingle underlayment
- Provides a waterproof barrier under the shingles
- Prevents water infiltration from pooled water from the ice dams
- Proper Ventilation
- Creates a cold roof system so the temperature of the roof sheathing is close to the outside temperature
- Adequate and balanced amounts of outside air need to be taken into the roof system at the eave and exhausted at the ridge
Use our Nailbase Ventilation Calculator to help determine the amount of airflow required in your ventilation nailbase system, or use our Attic Ventilation Calculator to determine the proper NFA for attic ventilation.
Q: How do I specify a full system warranty?
A: Specification of a total system warranty requires consultation with a membrane manufacturer’s representative during the specification process. Care should be taken to ensure all components included in the specification are supplied and installed in accordance with the manufacturer’s instructions for a total system warranty. When it comes to roof edge specifically to be included in a total system warranty:
- Roof edge must be approved through your membrane company
- Roof edge must be purchased through your membrane company
- Roof edge for these projects may carry a separate brand name, labeling, or FM rating than materials not intended to be used in system warranted projects
- Roof edge ES-1 or FM testing must exceed the required pressures to comply with the system warranty requirements, i.e. wind speed, uplift pressures, or FM requirements
Q: Which membrane manufacturers utilize Metal-Era products within their warranted systems?
A: Metal-Era supplies products to most all of the major membrane companies in the US and Canada, and some partners’ products can be found on our website. As identified above, often these products carry differentiating markings or unique features which enable their use at higher wind speeds or for longer durations in longer warranted systems. We strongly recommend that you consult with your local representative from the membrane company you are selecting, and consider the benefits of both the Metal-Era warranty and the various total system warranties available in the market today.
Q: What does Miami-Dade approval mean?
A: For a product to be Miami-Dade approved means that the Miami-Dade Building Code Compliance Office has reviewed and tested the product and it meets specific criteria for construction in Miami-Dade County, Florida. More info can be found on the official Miami-Dade County website.