[RE-wrenches] Flashing vs Sealant... again (is sealant code defensible?)

[Troy Harvey]

1. I'm interest in a poll of installers who are using flashings vs sealant. Now that the flashing market has evolved, what are you using today? When did you switch to flashings (if you did). And why not, if you still prefer sealant.

2. Is there a any code defense for sealant systems ? (L-foot sealed down to shingles). Does anyone know of a scientific shootout between sealants and flashings?

Here is my view: The construction industry is slow to evolve. Sealants, clauks & adhesives are not trusted in general, due to the legacy of code, and we have a mechanical vs. chemical industry bias. 

There is something about seeing a flashing that says, that is a "professional job", it must comply with code. And yet, my experience says I'd trust a 50-year silicone over a flashing that depends on gravity. Gravity should be dependable right? But anyone in snow country can tell you in spring, water can go uphill after ice dams form. There are high-rise buildings that use "structural glazing" which is just glass and silicone. These systems are now getting to be 50 years old without issue.

The cost of flashings have come down in the last few years, but so has the cost per watt of installs. With 50 feet in a typical install around here that is $150 in feet, lags & silicone. Or $1500 in flashings, and extra labor. That can be a large part of a bid, and make you more expensive in a competitive landscape. That is fine, if it adds value... but I personally don't see the proven value, other than the "appearance" of code defensibility. Anybody have proof?

thanks,

Troy Harvey
---------------------
Principal Engineer
Heliocentric
801-453-9434
taharvey at heliocentric.org
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