REMOTE retrofit: Mudsill air seal?
I’m working on a REMOTE retrofit one wall at a time. I have the siding stripped to the board sheathing and replaced the bottom ~2′ with osb sheathing for future seismic retrofit. I’m using Grace Select as the air/vapor barrier and lapping it over the mudsill (then heating to increase the bond) to the concrete foundation.
My question is how redundant is enough for air sealing? My plan to lap the Grace over the potential air leak will work but for how long? Should I take the extra step of applying liquid flashing over this joint then lapping the self sealing membrane over for double protection?
In Seattle if that matters for this.
Thanks!
Pat
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Replies
Pat,
To be honest, I'm not sure about the durability of the bond when Grace Ice & Water Shield is applied to concrete. The durability of the bond depends in part on the width of the overlap, as well as the dustiness and cleanliness of the concrete.
The answer to the question, "Is this a good enough method of air sealing?", depends in part on your goal. Some homeowners are aiming for Passivhaus-level airtightness; others have less stringent goals.
Clearly, there is no harm (other than the added expense and labor time), and a possible benefit, to caulking the joint between your mudsill and the concrete foundation before you install the Ice & Water Shield.
"Should I take the extra step of applying liquid flashing over this joint then lapping the self sealing membrane over for double protection?"
Be careful--I have come across many comments about tapes/membranes not sticking to liquid flashings, particularly the STPE formulations (Prosoco, Tyvek WB+, etc.)