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Focus on Roofing Applications for Adhesives and Sealants

Posted on 8/23/2012 8:23:06 AM By Bob Braun
  

This is the tenth blog in the ASC Building Products series and is beginning a journey into the many uses and functions for both sealants and adhesives in roofing applications.  In earlier blogs I focused on the roof from the view of air sealing which is one major use of sealants for roofing…

  1. Seal the wall roof connection
  2. Seal all wall, roof, and attic or roof penetrations e.g. conduit and pipes, windows and doors, chimneys and roof vents etc.
  3. Seal all gaps and joints in the exterior roofing material at parapet walls
  4. Seal the many air leakage paths that interconnect within roof cavity and between ceiling or within attic spaces. These paths are related to the routing of many utilities like HVAC, electric, plumbing…

In addition, there are many additional roofing sealant/adhesive requirements and applications for both commercial and residential roofing.  In fact, it hard to imagine how modern roofing could be wind and weather proofed without adhesives and sealants.

There are numerous adhesive and sealant products that are utilized in the above…elastomeric sealants, foam sealants, adhesive tapes and mastics, spray applied, trowel applied, and roller applied adhesives as well, etc.  Some elastomeric roll-on products even double as adhesives and coatings combined.

Now I would like to categorize several functions for both roofing adhesives and sealants so that we can then drill down on the details later related to the practical use as well as the test standards for these products.  Those involved in roofing know that there are many classes of roofs and most require that very specific standards are met to assure compliance to the building code.  In general a roof covering assembly can be classified according to:

  1. wind uplift requirements
  2. fire resistance level
  3. insulation requirements
  4. weather and water-proofing
  5. and more

We will focus on standards and applications related primarily to a-d above.  And we will begin with wind uplift testing standards in this blog.  Since an adhesive is one component of many in a roof covering assembly (outer membrane/material, insulation, substrate) it is nearly always tested as a partial roofing assembly.  The code will specify what wind uplift is required and there are many test labs which can perform these relatively large scale tests.  Below I list standards related to roofing sealants and adhesives:

View 51 active ASTM Standards and 4 Work Items for “roofing sealants.”

View 92 active ASTM Standards and 7 active Work Items for “roofing adhesives.”


Here is a negative pressure test assembly being used on a newly installed roof section:

negative pressure test assembly being used on a newly installed roof section


Related videos:

EFI Global Negative Pressure Testing Demonstration.

VIEW WIND UPLIFT TEST VIDEO.


Large scale roof assemblies ready for laboratory uplift:

large scale roof assemblies for laboratory uplift

In the next Blog #11, I plan to discuss the use of several specific wind uplift standards related to testing roofing adhesives and how they are used by various codes. Later I will drill down on b, c, and d items from the above list as we develop the story for roofing adhesives and sealants. Then I plan to focus closely on the critical role of sealants in a successful roofing assembly.   



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