Wow, the ultra-rare sextuple octuple-post!

Ugh it keeps saying failure to create post!

Building a shed in the backyard. Got it dried in and after first rain see this water on the floor. The studs are dry and the sawdust sitting on top of bottom plate is also dry. No signs of roof leaking.

I used ZIP sheathing and ZIP liquid flash at the joint of concrete slab and sheathing. The wall is concrete / sill sealer foam / pressure treated bottom plate.

Where is the water from? enough to wet your finger when you drag across it. Could that much water wick up thru the concrete?

Thanks for all advice!

Do you have a curb on that foundation?

No I do not. It is flat.

I'm not an expert, but very interested in what the answer is from those who are. It sure seems like it could be capillary action in the concrete slab from water in the soil. It is a real thing, but not sure if it's a thing in your case.

Jason_InfinityRoofer said:

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It could be just wicking through your zip system somewhere. But I think it's most likely wicking under where the zip meets the foundation. You could water test it but I think I would side that thing and get it past the foundation floor and then see how it does. I don't think you have a problem.

But this is obviously not my area of expertise so standby for other commentary.

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Yep, siding needs to go past the top of the foundation, and should solve that problem. This is for a basement, but you get the idea:

Liquid flash has to be done perfectly to work right. You can try applying it again to that side if you want and spay it down with the hose, but siding allows an imperfect installation to still be rainproof.

Will be glad to learn the problem/solution
We usually require an overhang of both sheathing board & siding
as I think I see in this video that may help
https://www.finehomebuilding.com/project-guides/insulation/installing-zip-system-sheathing-sheathing-to-foundation-connection
or
https://rebrand.ly/t5wz1iu

Is any part of the back of the zip damp to touch? From the picture it looks wet behind the stud. The zip system has a pretty thorough process of sealing at the joints. I'd be sure all those steps were done to the book (liquid flash at all fastening points, roll tape with that special press tool, proper sequence of flashing tape, etc.). Also, proper care of how that zip is base flashed at the bottom. No wood should be touching the concrete. Even the sill plate should have a gasket. Rain hitting the ground could also splash up the side of your slab and get soaked up by the osb portion of the zip. Lots of possible causes but my wild ass guess is a leak at the joint seams but that would show a pretty obvious damp mark at the base area. Maybe send the photos to Huber and get their two cents.

Good luck

Where is the water inside in relation to the window and door wall ?

Is the bottom window flange taped with zip tape ?

Did you roll all the tape ?

Did you flash the inside of the window and door jamb Before installing the window and door ?



Did you caulk the top window opening and 2 sides with silicone where the flange touches before installing the window ?

On your bottom plate , does it sit flush with the concrete or past it ?


What I like to do here is have the plate sit just past the slab, then have the sheathing dropped down about 1/4 to 3/8 on the edge of the slab, then the final siding hanging another 1/4 to 3/8 inch below the bottom of the sheathing

lower dirt away and give more a drop from slab to dirt, if possible.

You could then put a through wall flashing on top the zip wall and liquid flash that would go from sheating to concrete.

Put a silicone bead along the plate inside.

Solved?
No? Have one last idea ....

Not resolved yet. Won't be able to get back to the shed for another week or two.

Thanks everyone for the suggestions I will report back when I get back to it.