Navigating the Challenges for a Better Performing Wall Assembly

Presented by Hunter Panels – October 7, 2020

Session Recording

Session Questions and Responses

Q: What kind of vapor barrier can be installed over mineral wool?

A: Typically you will be looking at a permeable sheet good.  Something that lets water vapor out, lets the wall dry but does its best to prevent bulk water from entering. 

Q: If I wanted to eliminate stud cavity insulation within a wall and just use continuous insulation, can I still use the Prescriptive R-value method to meet the code, or do I have to use the U-value method? 

A: If you are going to take the stud cavity insulation out of the wall, you will need to use the U value method and certainly comply with the code by doing so.  It might actually reduce the amount of insulation you have in the wall.

Q: Is there an R-value of continuous insulation that will universally meet the code requirement in order to eliminate cavity insulation?

A: There is not necessarily a universal number, but in the US, I think it is around 15.6 R-value that will get you to where you meet or exceed the U-value requirements of a steel wall assembly.  There's a website called continuosinsulation.org that has a calculator to determine whether you are code compliant and does moisture analysis as well.  

Q: Where can I find the best information on nfpa 285 fire tested assemblies?

A; If you are building a wall that incorporates foam plastic insulation, you will need to go to their website, and it is incumbent on those manufacturers to provide you with test data.  There are a number of requirements to trigger nfpa 285 fire testing.  It seems like the insulation manufacturers have the most comprehensive testing and broadest information about the other products in the wall assembly because they trigger the requirement for the test.  

New to BIMsmith Coffee Club?

Stuck at home? BIMsmith Coffee Club is bringing continuing education credits to wherever you are. Join the Club to receive weekly invitations to free virtual CEU sessions provided by building product manufacturers.

• – Get AIA CEU credit for each session
• – Join once, attend unlimited sessions
• – Completely virtual
• – Free now and forever

--

BIMsmith is a free cloud platform for architects, designers, and building professionals to research, select, and download building product data. Search, discover, compare, and download free Revit families on BIMsmith Market, or build complete, data-rich Revit wall, floor, ceiling, and roof systems faster with BIMsmith Forge.