Sill plate moisture

[aventino68]

So in four places we have sill plate moisture. We're about to start finishing walls and we've noticed moisture sitting on the sill plate. In three areas it's just on top like the first photo which is looking down into the wall framing. Floor is well above surrounding grade, how do we get rid of what I'm thinking is the moisture condensing on the sill plate thats been cooled by the concrete floor. Second and third photo is where the bottom of the sill plate is wet which we think is maybe the plastic membrane torn underneath and letting the water in up through into the Sill Plate. Humidity is at 31% so it's pretty dry relatively speaking. We've checked and rechecked and checked again and there's nothing leaking in through the outside wall anywhere.

 

[BillK]

If you vacuum it clean and dry, how long does it take for the moisture to come back ? I would get it totally clean and then cut a piece of clear plastic to sit in the spot. Then wait and see if the moisture comes back under the plastic or on top of it. Maybe wait for a good rainstorm and go out and watch it ?

 

[PCustoms]

That's not condensation, that's a leak somewhere, and by the looks of the staining (rusted nails?) it's been getting wet for a bit.

 

[billconner]

That's not condensation, that's a leak somewhere, and by the looks of the staining (rusted nails?) it's been getting wet for a bit.

That was my thought too.

 

[PCustoms]

Also that sill should be pressure treated.

How old is this building?

 

[aventino68]

Building is 6 months old. When you all say leak you're talking 2nd and 3rd photos? thats a different spot from the 1st photo. I think 1st photo is maybe condensation. 2nd and 3rd photos I think are leak, we're struggling to find where from.

 

[PCustoms]

Building is 6 months old. When you all say leak you're talking 2nd and 3rd photos? thats a different spot from the 1st photo. I think 1st photo is maybe condensation.

1st photo looks like a puddle

3rd photo looks like the incorrect material was used. The wood has been exposed to a lot of moisture, either during the build or from contact with concrete.

 

[aventino68]

Ok so from further investigation the sill plates are attached to the concrete through metal straps that were put in the floor when the concrete was poured. Everywhere these straps are used we are getting the condensation on the sill plate.

 

[cgrutt]

That's really odd possible cracks in concrete wicking up ground moisture from metal connector attachment?

 

[PCustoms]

Ok so from further investigation the sill plates are attached to the concrete through metal straps that were put in the floor when the concrete was poured. Everywhere these straps are used we are getting the condensation on the sill plate.

What does your sheathing (and/or) siding look like in those areas?

I assume you had this building built, or was it DIY?

 

[walrus]

Air movement causing condensation in those spots

 

[aventino68]

Air movement causing condensation in those spots

Built by builder Royal Homes Wingham thats been around since 1971, so we thought maybe know what they're doing. So even with the plastic covering everything up, the Batts insulation fitted between the studs, you still are thinking it's air movement? All the sill plates all the way around are covered in water. We're thinking it's the cold floor cooling the warm sill plate enough for condensation to form.
Now we've opened up the plastic, removed the batts and put dehumidifiers everywhere to dry the walls out. But what to do after to stop the condensation or drag it out of the walls. We basically can't use a vapour barrier, I think

 

[walrus]

Built by builder Royal Homes Wingham thats been around since 1971, so we thought maybe know what they're doing. So even with the plastic covering everything up, the Batts insulation fitted between the studs, you still are thinking it's air movement? All the sill plates all the way around are covered in water. We're thinking it's the cold floor cooling the warm sill plate enough for condensation to form.
Now we've opened up the plastic, removed the batts and put dehumidifiers everywhere to dry the walls out. But what to do after to stop the condensation or drag it out of the walls. We basically can't use a vapour barrier, I think

Fiberglass batts aren't that good at stopping air movement. Tough to say without laying eyes on it. Hope you get it figured out. Have you gotten the builder back to look?

 

[aventino68]

I think what's problematic is the entire sill plate, all 90 ft of it is wet. Including under a deck where outside of house would see no water. Builder Royal Homes is doing basically nothing ( they said don't check in any more walls after we found the first water issues) so we're getting specialists in to look. It's what to do after we've dried it all out.

 

[billconner]

The sill is on the floor slab I believe. How far above adjacent grade is the slab? You say "well above" but I don't know if that's 2-3" or 12"+.

Any idea if there is a vapor barrier under the slab? Just not feeling like condensation to me but could be. Tape a 2' square of plastic to slab near a wall.If that doesn't show condensation overnight or 2 nights, I'd doubt it's condensation on the sills.

Stretching but any chance it could be rain or snow melt? I think you're not too far west of me and there's been a lot of snow and melt. I have 6" of ice on sidewalk next to my garage - with minimum 12" above grade block stem walls.

 

[Hank11]

Exterior pictures please, or you won't get much of an answer.