We have an 11 year old home with a poured foundation and vinyl siding. When we have a driving rain we have experience a slow leak at the top of the foundation wall on the side of the house that the rain is pounding the most. The water usually dissipates prior to reaching the floor so we are not experiencing any flooding. The basement is unfinished and the grade is good.

After doing some research and learning a lot more I think I may have diagnosed the problem myself as being a leak in between the sill plate and the foundation wall but want to get the opinion of experts. I am just a housewife trying to figure this out on my own!

We have had a basement waterproofing guy out but he did not mention this as a possibility. We were not sure if it was an issue with our siding and the windows because the problem is primarily under spots where there is a window. We do however have a couple of other spots including on a corner of the home.

When we have a good rain you can see that the foundation wall on the outside in these spots is wet, as if the water is getting underneath the siding. That is why we thought there might be an issue with the siding or flashing around the windows.

I should also mention that the cheap builder did a couple of short cuts on this house - including NO TYVEK! Also some of the outside walls they used blue board instead of plywood. You can tell during the winter just by running your hand against the wall and feeling where it gets colder.

I would like to know if you think I am right about the sill plate and exactly what I need to do to fix this problem. Should I caulk it from the inside in the basement removing the fiberglass insulation and placing caulk and then maybe some expanding foam insulation? Is there any caulking that should be done from the outside behind the siding? Do I need to have anyone come and take a look at the area to make sure no structural damage has been done?

Please Help Me - I live in southeastern Michigan so if you have any suggestions please pass them my way.

By the way - I also have some rod hole leaks - I was thinking of getting the product made my Mr. Sponge, any opinions on that?


Please Help Me!

We have a similar situation - leaking under the Pella casement windows when strong rains/wind occur on this side of the house. It is the walkout side so it is a framed wall sitting on a poured footing. Our house, too, has the same blue styrofoam board instead of OSB sheathing. Ours does have Tyvek installed w/ Hardie Plank cement siding.

Our basement is also unfinished, but does have insulation and plastic sheeting on this framed wall. The house is five years old and this is the first year we've noticed the leaking to the extent that it is on the floor. It could have been leaking before, to a lesser extent, that didn't make it readily known because of the insulation.

We feel our leaks are definitely related to the windows - whether it is the windows themselves or the installation of the windows.

We've removed the insulation and plastic sheeting, and can definitely see the moisture and dripping, but are still unsure where it is originating from. In some places, we see the dripping immediately and other areas aren't apparent for 30 minutes or more after the rain starts.

Since this is a walkout, we should also mention that we have windows directly above the basement level windows. Since our upper level is finished, we're unsure if there is or has been leaking around the upper windows contributing to the leaking in the basement area.

We've done "water testing" with our hose and have found a few areas to be caulked. We've caulked those and still have leaks.

We are curious if you have found a solution to your problem or if anyone else would have any suggestions as to steering us in the right direction.

Thanks for any assistance.

After I posted this message we had our roof redone and while up there our gutters were also cleaned out of all debris. Since then we have not had this problem at all (KNOCK ON WOOD!).

I wondered if the gutters were overloaded with debris and it caused water to get in behind the siding or something. You might want to check your gutters to make sure they are not clogged with leaves/misc.

Good luck with your situation!

Windowleak: your issue sounds like a flashing problem, and your windows may not have been porperly flashed at head, jambs, and sill. You won't want to hear the cure...I'm afraid it's "off with the siding", so the flashing deficiencies can be corrected.