What is causing moisture issue with basement sill plate?

5/18/2015 at 12:47:08 PM

Hi,

It will sound funny at first but, it is called hydraulics.

The water table around your house is pushing water up through your concrete, it will find the path of least resistance.

Because your problem is from outside water, I would recommend you solve this problem first, then you could use a product called xypex or similar to seal the cracks in your concrete better.

To fix your outside water table or water pressure, means to get the excess water away from your house. You could try to clean your drainage pipes with a special pressure washer head. I would call in a professional to do this.

If that doesn't solve your water problem then you need to look at new or better perimeter drainage.

When doing so, get three prices. The cost will scare you a bit.

Cheers,

Wayne Balliet

Project Manager

Builtru Construction

5/18/2015 at 1:48:43 PM

Yes, I have dealt with this. It's a high water table forcing water up through the concrete or your drainage tile is compromised. If you have one, do you have a sump pump in your floor? If not I would suggest putting an internal drainage system inside the basement walls going to a sump.

Brian

5/18/2015 at 2:16:26 PM

Thanks for the responses.

I do have a sump pump in the basement that works well and the weeping tile around the house, that appears to drain into the sump pump at a good pace during spring melt and heavy rain. This small area is the only place where small amounts of moisture seem to accumulate, which is why I was questioning the sill plate barrier. I literally have no moisture accumulating anywhere else in the basement.

Would it be a big job to remove the plate to get a good look at what is underneath it?

Also that sill plate is actually buried into the concrete an inch or so, while all the other ones rest nicely on top of the concrete. Could this be a source of the problem?

5/24/2015 at 11:51:46 AM

High water table is the actual source of your moisture problem. However having the sills in the concrete is a no no. Surprisingly the city passed your house. More than likely there is no concrete under those sill plates, which means they are sitting on gravel or worse bare earth. So they are sucking up the moisture from the ground and this is the weak spot in your floor where water will come up. It's like having a hole in your waterproof floor. You will have to support that floor and remove the sill plates and concrete that area before putting the wall back.