Tyvek detail at concrete/ply interface

[matt_i]

I'm to the point where I home-wrapped my shop building, after passing framing inspection.

The homewrap is done, but I have extended it below the concrete and plywood interface, far enough that it will stick out if left unattended, and needs to be trimmed back. If its important I have a concrete perimeter wall, 8" above the finished floor, and the sheathing ply butts directly to the crete, all in the same outer surface plane.

Part of me is thinking I should seal the bottom edge of the wrap to the wall to prevent air infiltration. The other part of me says leave it open to let any internal moisture drain away (they make purpose-built wraps with corrugations, or beads of hardened resin that create drip channels, etc for this very issue), or, a hybrid system of alternating open gaps and sealed strips.

Just curious what others have done. Thanks for any input.

 

[Kaizen]

i'd staple it well at the sill and use seam tape as far down as you can on the crete so it will be covered. not sure how well the sticky tape will adhere to the concrete though. another option is to run a piece of rubber tape like you seal windows with. when it gets hot that will get stickier to whatever its on.
the other system you are talking about I have seen on cedar shingles mostly. that is more of a living breathing wall covering.

 

[Bluedodge]

Your plywood (OSB?) should not physically touch the concrete. Water will wick into your wood. This will cause delamination and/or rot in the future. You should have a membrane, silicone caulk, or air gap between the two materials.

 

[matt_i]

Your plywood (OSB?) should not physically touch the concrete. Water will wick into your wood. This will cause delamination and/or rot in the future. You should have a membrane, silicone caulk, or air gap between the two materials.

The existing building I'm attaching to has a detail exactly like this, not even housewap, just the vinyl siding over the osb, which directly touches the 8" concrete wall (vinyl is lapped over so the wood is under the siding). 18 years after it was built, I can detect no soft spots or rot in the 30' or so I've opened up. One benefactor is that a full gutter system is used, so there is not much splash. I did consider for a short time latex painting the bottom edge and lower couple of inches of the ply, but it wasn't to be with the freezing temps as I was sheeting.

If there was some sort of double-sided butyl (ice & water sticky on both sides) I would probably consider that. But I haven't found that product yet.