Double Wall Construction Inspection & Possible Issues

(John Talanian) #1

Hi All,
I’ll be inspecting a double wall construction home soon. The client did some reading on the internet about some potential issues with condensation forming on the outer sheathing (due to improper air sealing). He’s very concerned that the home was built properly.

Home was built in 2013, 2"spray foam on outer wall with blown in cellulose adding the additional wall R value.

I explained to the client that a home inspection is a visual inspection only and we won’t necessarily be able to see inside the walls for proper construction or damages. While I am not currently trained in or using a FLIR camera I did explain that having a trained professional use one on the home may allow you to see signs of improper air sealing and potential heat signature variances that might point to an issue with sheathing.

My question to you all is, what additional things can I look for while inspecting this home given that some double wall has had condensation/water issues on the exterior sheathing? Seems to me that I’d be looking for all the same outward defects I might see on a single wall construction but with a double wall. Any additional advice for me on this inspection?

Many thanks for any input you may have!
John

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(Barry Adair, TREC#4563 EIFSTX#39) #2

when the industry gurus have doubts & after fact proof of failure
especially with the poor quality of most construction/trades these days
what else does your client expect/need from you a generalist
i’d write hard of the damaged or absent materials & mold that can be seen & stress what can’t be seen with invasive/destructive testing by others
Lstiburek’s Ideal Double-Stud Wall - Fine Homebuilding

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(Barry Adair, TREC#4563 EIFSTX#39) #3

when the industry gurus have doubts & after fact proof of failure
especially with the poor quality of most construction/trades these days
what else does your client expect/need from you a generalist
i’d write specific concise narratives, no boilerplate comments, of the damaged or absent materials & mold, wdi, wdo that can be seen & stress what can’t be seen with invasive/destructive testing deferred to others
High R-Value Wall Assembly: Double Stud | Building Science
any materials exposed to moisture for over 24 hrs are suspect for mold even if dry the day of inspection

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(Barry Adair, TREC#4563 EIFSTX#39) #4

when the industry gurus have doubts & after fact proof of failure
especially with the poor quality of most construction/trades these days
what else does your client expect/need from you a generalist
i’d write specific concise narratives, no boilerplate comments, of the damaged or absent materials & mold, wdi, wdo that can be seen & stress what can’t be seen with invasive/destructive testing deferred to others
High R-Value Wall Assembly: Double Stud | Building Science
any materials exposed to moisture for over 24 hrs are suspect for mold even when moisture metered acceptable the day of inspection

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(Barry Adair, TREC#4563 EIFSTX#39) #5

when the industry gurus have doubts & after fact proof of failure
especially with the poor quality of most construction/trades these days
what else does your client expect/need from you a generalist
i’d write specific concise narratives, no boilerplate comments, of the damaged or absent materials & mold, wdi, wdo that can be seen & stress what can’t be seen with invasive/destructive testing deferred to others
High R-Value Wall Assembly: Double Stud | Building Science
any materials exposed to moisture for over 24 hrs are suspect for mold even when moisture metered acceptable the day of inspection

did an eifs over brick veneer, design change, that was a petri dish & cost $XXX,XXX.00s to tear off & remediate
you can’t just willy-nilly slap up insulation, air, vapor, moisture barriers & expect good results
bldgs need to divert or dry all moisture beyond normal ambient conditions

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(John Talanian) #6

Great insights, thank you!

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(Jeff Zehnder) #7

I build a few back in the 1970s and 1980s, the key we learned was humidity controls inside the home & double wall since in the methods we used it acted as a plenum.

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