Water in wood frame in Basement
Hi, I have an old cottage that was on pillars. We couldnt get ICF forms so we have had a poured concrete basement. The cottage is on a hill. Hill wall is all concrete and part wood on sides and bottom wall all wood. I asked for r10 XPs on the outside unfortunately they filled it in when I was back on site. It has water proof coating. Up to the sloping gravel than a couple of inches of bare concrete. To match the top it is vinyl, 1 inch EPs, house wrap and wood boards . On the inside I have some weeping walls so I am using water tight and 2 inches Xps, 2 inches Eps, 1 inch mineral wool (thermal break) and then another 2by4 stud wall with mineral wool. The concrete floor has XPS underneath and I am putting in EPS floor trays that I will do 2 sheets of ply wood for a floating floor. It is all taped and foam (no air leakage). Headers have XPS an mineral batt in ceiling. I am adding no vapour because of the basement. My question is at the bottom of the full wood wall there is inch of moisture (photo attached). When I reach my hand up I think the issue is it is a concrete footer, foam gasket (very small), and wood wall, which is exposed to the air underneath the vinyl. They didnt bring the house wrap from the footer up into the frame or have flashing. My concern is if I spray foam the outside at this joint I might cause problems and if I dig down a foot or two I could put in 1 inch XPS up to this joint would this do anything. My thought is my design is to have it dry to the exterior given all the insulation on the inside. I also have a brand new triple pane window installed and it is leaking in one corner. Thank you
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Replies
That looks more like condensation has run down that wall and pooled a bit at the bottom. If the water was coming up from the foundation, I would expect that sill plate to be more evenly damp, and not just damp on the side facing what I assume is the exterior side of the wall. If I'm right here, then you have moisture getting into the wall from inside, then condensing out on the cold interior face of the exterior sheathing (looks like planks). You need a vapor retarder on the interior to deal with this.
Can you describe the wall assembly from inside out for the specific area where you're seeing moisture problems?
Bill
Thanks Bill, The inside of the basement wall is wood boards, then house wrap, 1 inch EPS, and vinyl. I have already started to insulate one side with first 2 inches of XPs then EPS then mineral batt. I wanted to make sure I was doing this right with XPS as the first layer in the cavity and then I tape the XPS so there is not air leakage
So these are BELOW GRADE walls? Is there any earth in contact with the exterior of the wood portion of the walls? As Walta mentioned below, you want the soil below the level of the wood. I like to say "at least once course of block above grade" for the foundation wall, which ends up being 6-8 inches or so.
Bill
Just to be 100% clear the soil outside of the wall in your photo needs to be at least 6 inches below the lowest bit of wood!
If you allow dirt or mulch to come on contact with that wall it will rot away very quickly.
Do you think the required capillary brake sill gasket was installed under this wall? Generally, it is pink foam that peaks out from under the wall every so often.
Walta
Hi no these walls are not below grade. There is no soil on this side. The only gasket I see is a very thin piece of membrane. Not pink.
You have an unusual assembly and I'm not quite clear what it is yet. Could you share more photos, from farther back and from outside? A sketch would also be helpful.
A pic showing up close and in detail (NOT BLURRY!!!) of the side of that sill plate and whatever membrane is under it might help us to understand what is going on too. If you have something that can act as a capillary break under the sill, that's a big plus, but not all materials are going to work as capillary breaks.
Bill
Hi the cottage was lifted and put on a new foundation. We are on a hill. The backwall is all concrete. The side wall (picture included) is half concrete half wood. Inside I am using xps as the first layer on the concrete (did watertite coating) and also XPS inn the wood cavities. Then for the wood EPS to finish stuffing the wood cavity. Then I was going to add a 2by4 frame with mineral wool. No vapour membrane on ceiling or walls. I am half done. Most of the bottom of the wood wall cavities are not wet but one or two have small amounts of condensation (more pictures) attached. I had water leak from a window so ripped out XPS (can see area in picture) and letting it dry make sure it is fixed before putting it back.
Here is the quick drawing of the orientation of the walls