Capillary break at mudsill and girder.
We ordered Conservation Technology’s epdm gasket for sill for better air sealing on a rough foundation wall (crawl space). Long story we ended up deciding to increase the size of the mudsill from 2×6 to 2×8.
so now the epdm gasket will not span the full width- it’s not practical to return/exchange it. What cost effective product should/could we use as capillary break that could also be used with epdm gasket?
thinking capillary break right above foundation wall, then edpm gasket, then pt mudsill.
could the generally used foam sill sealer be used as capillary break with epdm then placed on top for better air sealing?
Or what is a better alternative?
(Is Drylock effective as capillary break at top of crawl space foundation wall?)
Similarly, what is best practice for capillary break under pt girder beam resting on concrete?
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Replies
LtB,
Since you already have the gasket, I would apply it to the sill-plate, and use a strip of regular foam sill-seal on the interior to cover the rest of the underside.
Use the same foam sill-sealer, or a piece of waterproof membrane like Grace I&WS, under the end of the beam.
Perfect thank you for your reply.
I wouldn't trust Drylock as a vapor barrier. The foam sill sealers are known to work, but aren't the best (too easy to puncture). My preference would be strips of EPDM roofing membrane on a new build, but that stuff can be difficult to buy in small quantities sometimes. An alternative would be to use the same HDPE material that I often recommend for retrofitting capillary breaks onto existing structures. You can get HDPE cut into strips from any commercial plastic supply house. Just get strips maybe 1/2"-1" wider than the gap your EPDM gasket misses, then place the HDPE strip in that area so that the gasket overlaps it a bit and can seal to it. You can use 1/32" or 1/16" HDPE here, it doesn't need to be super thick.
Bill
Thanks for your input. I’ll look into the HDPE.
If you are in a termite prone area, PolyGuard makes a product called TermBarrier that functions as both a termite barrier AND a vapor barrier/ capillary break. I don't work for them, just a satisfied customer. Note that the substrate does need some prep and you need to use their primer to make it adhere well.
Thank you. I think I have seen that. Will take another look.