Home>Discussions>EXTERIORS>Leak in basement foundation wall
7 posts / 0 new
Last post
Leak in basement foundation wall

Hi all: This is the first time I have posted although I have learned a lot from reading posts. I will try to tell this story as simply as I can! I did not see a Forum for basements/foundations specifically, so hope it is okay to post this question in the Exterior forum.

I purchased a townhouse a little over a year ago. It has a small basement, about 300 sf finished and about 250 sf dirt crawl space. The house is about 50 years old and the house is 15 feet wide with houses on either side attached (share a wall).

I was sick for a while last year and air tests discovered mold. The finished part of the basement was demolished. (the unfinished dirt portion is a whole other story!).

Paneling was taken off the walls. The foundation is cinder block. In the rear cinder block wall, a previous owner had punched holes for electrical outlet boxes about a foot or so off the floor.

Shortly after the remediation was completed, a pipe burst outside on my patio. Water pooled in a couple of spots outside (I had installed a flagstone patio with stone dust base). When I went into the basement to shut off the water, I heard water trickling inside the cinder block walls. I looked in those holes that had been punched out and I could easily see water dripping right through the cinder blocks, and water was sitting inside the walls. I was able to pump most of it out with a siphon but some of it still sits near the footers. I believe this was a problem in the past also because I now see that two of the electrical boxes that were sitting in these holes have rust or water marks on them - quite a safety hazard! However, since I have moved in there have been some big rainstorms and no water has come into the house and onto the floor -- it seems to be only in the walls.

So, water is traveling from the surface, apparently around the outside of a window well (there is no water inside the window well), and into my wall. You can hear it trickle when you are outside the house so it must have a pretty direct path. The water that was pooled was a couple of feet away from the house, just past the window well.

Some companies want to install an interior drain and sump pump system along the inside back wall (I already have a sump pump in the other part of my basement, toward the front of the house). They say this is guaranteed for life. This will drain the current water and catch any future water that comes down the wall. Water would still be coming in through the wall but it would be drained.

Other companies suggest excavating the outside of my rear wall and waterproofing it from the exterior. Most expensive option, not guaranteed for life but for a number of years and would hopefully prevent water from coming in in the first place.

Third option recommended to me is pouring concrete adjacent to the house instead of my flagstone/stone dust patio to create a surface barrier so that water could not get into the ground but would instead flow off to the back of the patio away from the house-- I guess it would be sealed to the window wells and the outside of the house that is at/above grade, but how far would it have to extend away from the house to ensure no water gets into walls and how tight a seal is this? This is least expensive but not pleasing aesthetically and not sure if it will work.

Those are the options that have been offered to me, I am really not sure what to do. i am on a very limited budget, so I would like the least expensive option, but I don't want a temporary or sub-par fix. I want to make sure there is no more water coming into the basement, especially given the previous mold history. The basement is poorly ventilated. I just don't know if I really need the entire back wall excavated or the interior drain system.

Clearly there is an obvious pathway from the surface to the wall, but wondering if there is something short of a major project to fix this. Any advice would be most welcome!

Re: Leak in basement foundation wall

You need to address the cause, not just treat the results.

Digging outside and waterproofing the exterior is the only way of achieving this.

Re: Leak in basement foundation wall

Thank you, dj1. This has been my instinct but it is so hard to know when one gets different recommendations from various parties. I really appreciate your taking the time to read and respond!

Re: Leak in basement foundation wall

I think you need a two pronged approach. The first is the excavation and waterproofing of the foundation walls. Get several estimates on this and then check each out with the BBB and any other organizations in your area. If only one wall is leaking, then you should be able to get by with just doing that wall, for now anyway.

The second thing that needs to be done is grading the yard around your foundation so that water flows downhill away from the foundation for at least 10 feet, 20 would be better. But, do NOT do this with concrete. You cannot pour concrete right up to the foundation wall because concrete will expand and contract with temperature changes, this could crack your foundation walls. There has to be a gap and if there is a gap, water will get funneled down into that crack.

Your current flagstone patio should slope down hill away from the house. It only needs to slope about 1/8' per foot to shed water. The stone dust should be OK if it is right up to the foundation as it was some elasticity in it. The rest of the yard should be graded so that you have the needed slope to keep water away from the foundation.

It is possible that just taking care of the grading will solve your problem. If you have real sandy soil, you should have some clay soil brought in and mixed with the sandy soil out to about 10 feet from the foundation.

Since you are in a townhouse, you may have to work with your neighbors a little when you do the grading. You have to make sure that any grading you have done does not aggravate any existing problems for your neighbors. It would be worth a visit with each of them to find out if they have any problems in their basements right now and if they do, have a witness with you so they can't claim later that you grading effort caused their problem, that it was a preexisting problem.

This can get to be a sticky issue if you want to grade and you have a neighbor who has landscaping that might get disturbed too. If your grading is not adequate, you might talk with your communities code enforcement about options in case you run into a conflict with any neighbors. They may be able to compel a neighbor to not only allow you to grade, but for them to also participate at their expense if their property is contributing to your problem.

Re: Leak in basement foundation wall

Waterproofing all your exterior things will help you out. And use good brand for long lasting results.

Re: Leak in basement foundation wall

Water belongs in fixtures and pipes or on the outside of your house. When it doesn't stay there you will have BIG problems. Waterproofing goes on the outside of a house or the house is not waterproof.

It's easier to remember like this: If the waterproofing is on the outside it is a house. If the waterproofing is on the inside it is a swimming pool.


Re: Leak in basement foundation wall

The easiest first step is making sure all your downspouts are directing water away from your house and when it rains water is running away from your house, and that your neighbors water isn't dumping on your foundation. Then if that doesn't fix it and you are filled with buckets of money and can afford to have the foundation dug out and waterproofed a footing drain installed to get the water away from the house go for it. I am in Seattle so I know about wet basements and one of the ways it is resolved here if you don't have $20,000+ is from the inside with the plastic/rubber mats on the walls that feed any water that gets in through the walls down into the floor where the concrete is dug up and a trench is installed with a french drain kind of thing around the perimeter of the basement then the water is all directed to a sump. That system works pretty good here and it sounds like your basement is already been gutted so not that big a deal to do vs actually digging up a foundation. Now if you had a completely finished basement it might be a draw on what would be a cheaper option.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.