BASF Paint on WRB air sealing and tyvek transition
New construction climate zone 6b. I have a mix of boral siding and BASF EIFS planned. We have 3” polyiso over OSB, then tyvek (outtie windows) rain screen gap then the boral. The EIFS is planned with 3.5” of EPS in the BASF Senerflex Channeled Insulation Design.
The transition between the tyvek and roll on/spray on senershield is proving troublesome. BASF tech support said the senershield must not be applied over 3m 8067 tape or tyvek tape.
I was planning to use the 8067 tape to air seal my primary air barrier, the OSB sheathing. BASF tech support said senershield is a suitable air and water barrier.
1) How good a job will senershield do in air sealing the sheathing? Outside corners, larger gaps and flexibility would be my concerns.
2) What is the best way to transition between tyvek and the senershield considering the senershield shouldn’t be applied on top of tyvek tape and neither should the senergy adhesive coating be applied on top of tyvek?
Cheers
Steve
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Replies
I would check with BASF, lot of EIFS can be installed over a polyester-faced peel and stick. You can use strips of this to seal your sheathing or just wrap the whole section in it.
+1 on what Akos said. Looks like BASF calls theirs "Sheathing Fabric". Maybe this fabric will stick to other tapes? Or, with the fibers, work well alone (replacing the 8067).
Polyester-faced peel and stick, is that the roofing tape stuff? That will be a good method for sealing the OSB joints instead of the 3M 8067?
What are your thoughts on the senershield as a primary air barrier to seal the OSB. The BASF rep said that it should seal joint gaps in OSB well. I'm not convinced that you can get the film thickness needed at external corners to effectively bridge a gap and accommodate thermal shift and settling.
I should add that one of the options I'm looking at is doing away with the Tyvek on the outside of the polyiso and just going with the senershield over the whole house as the wrb/air barrier.
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I used 3m 8067 tape and can understand why you would not want to coat over the tape. I has a smooth glossy feel on the back of the tape. I think you could apply the tape over senershield coating to stick it to the tyvek. do a test and see how it sticks to the coating.
I used Henry's Blueskin VP100 on my project as the WRB and air seal, no application or thickness problems.
Tim did you use the 8067 and the Blueskin VP100? What sort of ACH numbers did you get? Do you think a spray on paint on process is robust and flexible enough over the life of the house?
I would only trust fiber reinforced mastic for panel seams for long term air sealing, not sure I would trust a spray applied sealants.
You'll have to search for what polyester faced peel and stick you can find locally. Something like this:
https://www.master-builders-solutions.basf.us/en-us/products/air-barriers/masterseal-awb-970-fib-flexible-flashing
https://foursevenfive.com/tescon-vana-200/
https://www.soprema.ca/product/sopragrip-f-471/
The roofing stuff usually polyester reinforced, not what you want.
Steve,
I did a remodel so, no blower door testing needed. I seemed to make the house ant proof in my remodel process. I used the blueskin as the WRB & air barrier. It is a peal & stick and could be done incrementally as I progressed on my project. I used the 8067 for window & door flashing.
Check out https://www.youtube.com/user/MattRisinger on youtube - he has some videos on liquid applied WRB. I don't know about your long term performance question on the liquid applied. But, like all waterproofing it comes down to careful installation.