![metal roof attachment through insulation metal roof attachment through insulation](https://www.aescurb.com/files/2016/03/skgi_4079159_15297.jpg)
(Indiana still adheres to the 2009 IECC.) The billowing roof membrane can also create a sound issue for the owner as it flaps up and down.īecause of the billowing effect, a mechanically attached roof membrane does not count as an air barrier a separate air barrier would need to be installed below the membrane (likely below the insulation layer as well).
METAL ROOF ATTACHMENT THROUGH INSULATION CODE
For states that have adopted the 2012, or later, International Energy Conservation Code (IECC) an air barrier is required on the roof and walls. (For more information, see the Oak Ridge National Laboratory 2013 study: Condensation Risk of Mechanically Attached Roof Systems in Cold Climate Zones).īeyond that, the billowing action is not energy efficient because the building loses conditioned air above the roof membrane. Since the membranes are typically white, they do not gain enough heat to warm the top layer of insulation and drive the moisture back down into the building. Over time, this can wet the insulation which reduces the R-value and can lead to mold. In the winter, this warm conditioned air cools and can condense on the underside of the cold membrane. There are two primary options for attaching the TPO membrane: mechanically attached and fully adhered. For example, if the owner expects workers to routinely service rooftop mechanical units, a thicker roof membrane should be considered. The thicker the membrane, the better the long term durability. In Indiana, we typically see 45 mil and 60 mil specified. TPO is typically sold in thicknesses of 45 mil, 60 mil and 90 mil. No matter which option is chosen below the membrane, this is how all TPO roofs are sealed at the seams. While it is still plastic, a roller is used to fuse the top and bottom membranes together, forming the watertight seam, typically 1 ½" wide if done by robot or 2" wide if done by hand. A hot air welder is used to heat the membrane above and below, turning it to plastic and making it moldable. Thermoplastic means that it becomes plastic upon heating and hardens upon cooling, and this is how it seals at the seams.