Low slope roof penetrations can be a source of problems if not done correctly. Pipe, vent, and conduit penetrations through low slope roof assemblies can cause problems for an otherwise tight membrane, insulation, and deck design. With many intermediate layers in roof assemblies, such as a vapor retarder and cover board, there are opportunities for things not to be done correctly somewhere in the assembly. It gets even more complex when we consider that in order to use a vapor retarder, there might be an additional cementitious board above a steel deck.

Vapor retarders are increasingly being specified for inclusion in low slope roof assemblies. They can help manage humid air migration from the building interior up to the underside of the roof membrane. Also, they can help limit the amount of moisture migrating from a concrete deck up into the roof assembly. In fact, we offer the GAF SA Vapor Retarder, a self-adhering sheet product, to help reduce this risk. If you are designing a new roof and want to reduce possible moisture risks or are replacing a roof assembly where there's evidence of moisture issues, this article may help you to understand more about the use of vapor retarders.

When Bobbi Jones, 26, of Roxbury, MA, and Yeren "Jay" Rivera Cruz, 19, of Jamaica Plain, MA, were chosen from an impressive pool of applicants to join This Old House's team on Season 42's Dorchester project, they also got the chance to learn about the roofing trade from the pros.

Liquid-applied roof membranes (LAM) and roof coatings (aka, maintenance coatings) are not only here to stay, their use is on the rise. This blog takes a look at how the building code and the roofing industry generally differentiate between liquid-applied roof membranes and roof coatings. There is confusion because the intended use of each is different, yet many of the materials are the same for both applications. Here's what you need to know to help understand and differentiate between the two.