SpecTips - Minimizing Thermal Loss by Reducing Excessive Plates and Fasteners in Commercial Roofing Systems

Reducing Penetrations Through Metal Roof Decks

Metals decks are one of the most commonly used roof decks in the United States. The roof deck is an important part of every building, as it represents the top side of the building envelope. And while a building may have three or more roofs installed during its lifetime, the roof deck normally remains the same.

Mechanical fasteners through metal roof decks,and the holes they leave behind once removed, not only cause aesthetic issues (as can be seen in the photo to the left below), but they can also lead to thermal performance issues. The picture on the bottom right shows conduction heat loss from thermal bridging of the plates and fasteners on a dew-covered roof.

To address these issues, consider an insulation and cover board composite product that allows you to use a reduced number of fasteners while still providing the same or better performance than products requiring additional fasteners.



SpecTip
Your 3-part specifications should require the following:

• In Part 2 –Product Section, under the roof system products, make sure the system contains a cover board and that it “conforms to ASTM C1289 Type II, Class IV.”
• For Factory Mutual (FM) insured projects,in Part 1 –Quality Assurance Section, verify that the system is using an “FM 1-90 system.” A system with a cover board that meets FM 1-90 can require as few as 6 fasteners or less per4’x8’ board.
• In Part 2 –Product Section, under the roof system products, choose a composite product for the top layer of insulation, such as Carlisle’s SecurShield®HD Composite polyiso.

For more information on SecurShield HD Composite polyiso, visit Carlisle SynTec Systems’ website.

Visit Carlisle SynTec Systems’ Insulation