What is the generally accepted method for sealing vertical stud assemblies - locations where studs lie up against each other at corners, windows and other special locations?

Just as leaky as double top plates, but haven't heard much about what is typically done to seal those areas.   What do you do?

I don't think anything is typically done in those situations or for double top plates.

If you detail the exterior as your air barrier from foundation to truss bearing, (such as using ZIP sheathing) and tape off the joint of the sheathing to the top of the top plate, this helps to eliminate the issue. Same is true around corners. If your corners are taped off around them, it should seal them off.
Or you can use air tight drywall and gasket around the edges and plates.

The conventional way to seal them is to apply a bead of acoustic caulking to them. In Alberta with typical 2x6 exterior wall construction, the insulator installs the bats than applies a bead of acoustic caulk to all face joint of multiple studs including the double top plate. Also a bead in the angle between bottom plate and the floor. Than a bead around all windows and doors, hang the poly and push it into the caulk. Better than nothing!

Is "air tight drywall" a product? Or a method?

hang the poly and push it into the caulk

I'm convinced that MemBrain is a better choice than poly. Even more so when I see all this foil covered foam being sold (which I assume is non-vapor permeable).

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Posted By ICFHybrid on 08 Dec 2011 08:48 AM
Is "air tight drywall" a product? Or a method?

Air tight drywall is a technique.
http://www.buildingscience.com/documents/information-sheets/air-barriers-airtight-drywall-approach/

Air tight drywall is a technique.

Aha. Thanks.

From a framer's point of view, how hard is it to apply the sealant while you are framing?

And, I guess I'm also wondering how drywallers feel about this technique from a production standpoint.

From what I have read on other boards drywallers are not the biggest fans of the "goop" method of airsealing. It is rather messy when putting up the drywall, and I would suspect that in many areas it is "forgotten". There are manufacturers of gasket-type air seals (www.conservationtechnology.com is one I hear of often). Obviously these are less messy. And there are spray-type air sealing products (Knauf EcoSeal and Owens Corning EnergyComplete). These would be effective if your air barrier is to be at the outer sheathing. I personally plan on building with air sealing of both the sheathing and the drywall (belts and suspenders). Lots of good information available at BuildingScience and GreenbuildingAdvisor.

Posted By ICFHybrid on 08 Dec 2011 11:01 PM

From a framer's point of view, how hard is it to apply the sealant while you are framing?

Simple, unless your talking about airtight drywall in which case a framer would not be doing that with sealant, gaskets maybe.

Framers have the best access to critical joints during construction and thus are the most qualified to complete air sealing, not to mention they are physically creating the thermal boundary.  It's critical it gets done before later stages of construction block or conceal what needs to be addressed for a complete job.

Framers have the best access to critical joints during construction and thus are the most qualified to complete air sealing

It was discussed beforehand and sealant and guns were provided and loaded, unfortunately, they just didn't do it. I'm going to put 2" of spray foam up against the sheathing, so that reduces the number of places I'll need to seal.

At this point, I'm thinking a bead of sealant at the crack between all doubled 2X's.

I personally plan on building with air sealing of both the sheathing and the drywall

Makes sense to me.