Joint sealant
cord12
| Posted in General Questions on
Hello all,
We are in zone 6 Wisconsin and wondering which product is best for sealing joints in studs, OSB sheathing seams and occasionally concrete foundation to treated lumber. I have on hand Great Stuff spray foam and GE Silicon II caulk.
With the current low temps and high winds we have been having, we got fed up with one of our cold walls so we ripped out the drywall to take a look. Lots of 2×6 framing butted up (length wise) to each other. Air was pouring through every wood stud joint and OSB seam.
We like to get it corrected with a trusted long-lasting product.
Thanks,
David
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Replies
Great stuff probably won’t work well for the small gaps, it tends to fall off and not penetrate gaps too small for the straw to fit inside. I’d go with the silicone caulk. You can get an “extra stretchy” kind of caulk that’s good for bigger gaps, and anything that might move slightly. My guess is the stretchy stuff might stay adhered longer to things like framing and sheathing too, but I don’t have any evidence to back that up.
You may find the caulk won’t adhere properly in these very cold temperatures we’ve been having. If you’re making an emergency patch it’s worth a shot, but you might have to redo the work when it’s warmer to get a good seal. Make sure to get the caulk squished into the gaps and not just spread on the surface.
Bill
Order some 3M 8067 tape for the OSB seams(or zip tape, or Tescon Vana, or Siga Wigluv) and some liquid flash for the gaps in wood(Prosoco FastFlash or Joint and Seam Filler, or Zip Liquid Flash)
Right on Kevin -
I don't think this is the right application for caulk or sealant (see this blog series I wrote called Sticky Business, including several on sealants: https://www.buildinggreen.com/search/site/sticky%2520business).
PSA tapes and high performance flashing/mastic that Kevin recommends work.
Peter
Thanks to all for commenting. I have read about the liquid flashing and European tapes, I guess now my time has come to try them.
We did spray foam some of the larger gaps right after removing the drywall. Prior to foaming, I took surface temps with an IR thermometer and most were in the 5 - 8 degree Fahrenheit range. The foam of course just crystallized instantly, crumbling to powder if touch. Interesting, now days later, it has resumed a near normal form and texture other than off in color. I will eventually replace it, but found it amazing that the foam "tried" so hard to work in extreme conditions.
David