With taped exterior sheathing, is there any benefit to caulking each stud bay?
I have 1/2 cdx sheathing taped with zip tape. I takes the sheathing to all window rough openings as well. I was planning on caulking or applying acoustic sealant to the crack between the sill plate and the bottom of the sheathing and again at the top plates. The sheathing was not glued or gasketed at these joints.
Since all of the other sheathing joints are securely nailed to blocking and taped with ZIP tape I presume there is no point to caulking the stud bays?
As a side question, is it possie to substitute roofing tar in place of acoustic sealant? I am referring to the large tubes of roofing tar that can be used in caulk guns. Seems like it would work at a much cheaper price point. If not, please share your thoughts. Does anyone has a decent source for acoustic sealant? I can’t find it at the box stores and it’s very expensive online.
Finally, I just wanted to say how great the zip tape is. While plowing snow I damaged a section of sheathing (backed into it with trailer hitch) and had to replace a section in the cold of winter. The zip tape I had applied three months prior was stuck so well to the cdx plywood that it literally pulled the wood off the plywood! This was in cold weather. I’m impressed.
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Rick, to answer your second question. Acoustical sealant shares one attribute with roofing goo: they both somehow manage to adhere to clothing, tools and the seat of your truck. Where they differ is that roof goo hardens and becomes brittle over time. Acoustical sealant stays soft for decades.
Malcolm, thanks for that clarification. I have never used acoustic sealant before.
Rick,
No, you don't have to caulk the seams that are already sealed with tape.
Tremco acoustical sealant may seem expensive, but it's a good product and is worth the price.
for acoustical sealant. Try to locate USG brand in the Giant Size tubes (28oz?) Real cheap compared to using the small tubes. I get it from my commercial drywall supplier.
While not as flexible and elastic as say Dap Sidewinder (oil based, but awesome flex) the USG stuff is pretty much on par with Dap premium lines of latex caulk.
Dirk, Is the USG an apples to apples swap for Tremco? I've used it in sound attenuation projects. It seems more like caulking to me.
Thanks everyone for your suggestions. If anyone else can comment on the effectiveness of the DAP or OSI latex based acoustic sealants, I would be appreciative.