Building Science

FEATURED
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.
LATEST NEWS
Cool roofs can help save you money on cooling costs in the North as well as the South. Here are some cool truths to ponder when planning a new roof.* TRUTH 1: It's All About Reflectivity A cool roof reflects the sun's rays away from the roof, helping to reduce rooftop temperatures. While a sunlight-absorbing black roof can reach up to 190°F in the summer, a reflective roof's temperature can be as much as 55°F lower. Dark surfaces also contribute to the urban heat island effect. (SOURCE: heatisland.lbl.gov/coolscience/cool-roofs)
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.
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.
Don't Miss
Another Post
A common question being asked in the roofing industry is whether or not the 2016 version of ASCE 7 is going to increase the design wind pressures acting on a building. The answer is "yes" in many cases. So, the follow up question is "by how much?" And, that leads to the next question, "how much more capacity will roof systems be required to have when wind design follows ASCE 7-16?"
What are the key material properties?In a previous article the use of thermal inertia to slow down heat flux through a roof assembly was discussed. In buildings where air conditioning costs dominate and heating use is relatively low, higher thermal inertia assemblies can potentially improve energy efficiency. This is particularly the case of buildings such as offices that are only occupied during daylight hours. Thermal inertia could delay the transmission of heat into a building towards the end of the day, increasing thermal comfort and allowing facility managers to reduce cooling during the day.
Thermal insulation is an important part of commercial roofing assemblies. As with anything, there are ways to design with and install polyiso insulation — a better way, a best way, and many variations in-between! What may be best in terms of lowest up-front costs, may prove only good or worse over the long-term life of the building.
Showing page of
VIDEOS FROM GAF
VIDEO ARTICLE
Air Barrier vs. Vapor RetarderWelcome to Episode 4 of The Building Science FAQ series.The Building Science FAQ video series explores some of the technical questions that crop up when specifying a low-slope roof.
VIDEO ARTICLE
Air Barrier vs. Vapor RetarderWelcome to Episode 4 of The Building Science FAQ series.The Building Science FAQ video series explores some of the technical questions that crop up when specifying a low-slope roof.
VIDEO ARTICLE
Air Barrier vs. Vapor RetarderWelcome to Episode 4 of The Building Science FAQ series.The Building Science FAQ video series explores some of the technical questions that crop up when specifying a low-slope roof.
This blog contains information created by a variety of sources, including internal and third party writers. The opinions and views expressed do not necessarily represent those of GAF. The content is for informational purposes only. It is not intended to constitute financial, accounting, tax or legal advice. GAF does not guarantee the accuracy, reliability, and completeness of the information. In no event shall GAF be held responsible or liable for errors or omissions in the content or for the results, damages or losses caused by or in connection with the use of or reliance on the content.

Interested in sharing or republishing our content? We kindly ask you to adhere to our guidelines.