Sealing concrete leak?

[ctfjr]

In the basement of this new to us house there is a small water leak next to where I garage the Kubota. It is at the floor / wall intersection. It's not much of a leak but when we get very heavy rains it seeps in and forms a small puddle, usually not any bigger than 2'x4'. The PO was upfront and told me about it and said it wasn't anything that bothered him. It bothers me now that I see it.

Digging up outside is pretty much out of the question for several reasons. I have heard there are patch materials that will work here but I have no experience with anything like that. Any suggestions?

 

[GreensvilleJay]

You might try hydraulic cement or one of the 'fancy' materials but...
when you plug THAT hole, the water will go elsewhere.....
maybe sending your Kubota where the Vettes went.....

 

[Biker1mike]

Any hardware store will have cement patch that will work on the inside of the basement.
A bigger issue may be the water on the outside that is getting into the wall. Freeze and thaw action may make it larger as time goes on. Been there.

 

[D2Cat]

Like Jay said, hydraulic cement is the answer however you need to examine a way to relieve the water on the outside.

The hydraulic cement can be purchased in small containers at any hardware store. Mix it in a plastic container like Cool Whip comes in. Use water to make a paste the consistency of mayonnaise (or a bit dryer) and force it into any hole/crack. Clean the edges of the hole/crack of any loose material or jagged material with something like a flat screwdriver. Pack it in the opening with pressure to force it as deep as possible. It is an amazing product.

You can actually mix it pretty dry and stop a water leak as it is flowing!

 

[Runs With Scissors]

I have never had much luck with "hydraulic cement" (unless you define success as making a giant fu@@ing mess and then having it leak at the very next rain event)

I did however call a company out about 20 years ago to "inject poly-something" into my crack and it has worked out great. I remember it being about 350 bucks back then.

Basically they drilled a series of holes about 15 inch's apart and screwed the tool into each hole and filled it until it squirted out the next hole.

I think they sell 'do it yourself" kits now, but I haven't tried them.

Paul

 

[ctfjr]

Thanks for all the replies. I'm sorry if I didn't make myself clearer in my post. The 'crack' is just a small space between the floor and wall. It's almost like the floor 'shrunk' and left this <1/8" space.

The area I'm talking about is ~8' below grade. The grade slopes down to the rear corner so I have a garage in the basement. The PO says he installed drainage pipes leading into the woods behind the garage. I did find one of them so I don't doubt him.

No other part of the basement gets any water but it is a concern that somehow plugging this will force it to come up nearby. . .

 

[North Idaho Wolfman]

Drill a few 1/4" holes above the leaking area, at a 45 degree angle down into the joint, the inject epoxy.
Clean the holes out completely before injecting epoxy.
Other option, spray foam, the foam will creep and seal any gaps.

 

[Kubota Newbie]

Basement and foundation leaks associated with rainfall events are often caused by improper grading around the foundation. Best to check and/or address that first.
In no case should the earthwork around the foundation be sloped toward the house. It should always slope away. I like to tell people at least 6 inches lower 10-15 feet out from the house . Sometimes you can't get that. In those cases anything is better than nothing.
Any amount of surface runoff can easily overwhelm foundation drains, even if they'd installed them pretty well.
If your foundation drains go out into a wooded area then root intrusion and plugging can be a BIG problem. You just have to keep an eye on that.
But again... first things first, eliminate any water that may be moving down along the foundation in that area from the top, surface runoff, roof runoff, down spout water, sump pump discharge (if you have one), and then consider sealing on the inside IF the issue continues.
Having it happen only during heavier rain events is a clue that it's related to extra runoff or a discharge that happens only during rain events.

 

[DustyRusty]

Contact the seller and ask how many drains were installed, and where. Then find the drains and see if they are running when you get heavy rains. I installed a 4" perforated pipe under my floor on the inside and at the bottom of the footings on the outside and connected them together before the footings were poured. When we get heavy rains, the drains collect the water and it exits away from the house in the woods below. Mine have been in place for 40 years and have never clogged or have they ever given me any issues. As distasteful as it is to dig to the bottom of the foundation, it might be necessary since that might be the only way that you will be able to collect the rainwater and relocate it on the property where it will not be a problem. You need to get below the footings to be successful, anything less and you are just wasting your time and money.

 

[NCL4701]

Agree with Kubota Newbie. By far the best success I’ve had at stopping basement leaks is to get the water away from the house.

Even if you deal it successfully on the inside to keep the water out, there’s still a potential issue of hydraulic pressure against the wall with the water that was coming through the wall sitting just outside the wall. Depending on the quantity of water, height of the wall, and construction of the wall that can cause structural problems far more problematic and expensive than a wet spot on the floor. Often, a leak such as that is a canary in a coal mine so replacing the canary often doesn’t fully address the problem.

Getting the water away from the house would be my Plan A. If you decide to seal from the inside, keep a close watch on the wall for any horizontal cracks or other signs of deflection and address the water from the outside early and aggressively at the first sign of any movement.

 

[JimmyJazz]

Make sure your gutters and downspouts are functioning properly. The best way is to go outside during a torrential rain and observe. In the northern climates the downspouts can freeze solid and rupture the seam on the back of the downspout pipe thereafter making it a potential problem. It took a long time for me to figure this out. Good luck.

 

[The Evil Twin]

Slabs are poured before the walls. They are not one piece. That's why there is a gap.
There should be drain tile around the foundation. It may have collapsed in,or have been installed wrong. The key is to get water away. Not plug the leak. Water will just find a new path. An internal patch may work for a little while...till the water finds the next path of least resistance

 

[mikester]

Fix your drainage problem - move water away from the building through grading, drainage

 

[ctfjr]

Thanks for all the input.

The grade does slope away from all sides of the house, built on a knoll. The one thing I can try and check is to see if all the piping from the leaders are clear to the woods. The previous owner did pipe everything back into the woods. I just need to find the end points and see if they really are draining well.

I don't think the issue is the gutters / leaders. In looking at the town map of the property there is a tributary to a river that starts in the woods directly behind the basement garage. I was told that in the spring or times of heavy rains water will 'appear' there. I believe the groundwater level just rises. Its about the same level as the basement floor and ~75 feet away. . . If that's the case then there is no hope of a simple drainage solution.

 

[L35]

Cut a hole in the floor and drop in a sump pump at that point.

 

[The Evil Twin]

Yup. If you can't dig, a crock/ pump is going to be the answer.

 

[ctfjr]

I have thought of that. As much as I don't want to do it it may be the best solution. I'd make a 18"-24" diameter hole and go down 36". Fill it mostly with stone and install the pump on that.

 

[The Evil Twin]

I have thought of that. As much as I don't want to do it it may be the best solution. I'd make a 18"-24" diameter hole and go down 36". Fill it mostly with stone and install the pump on that.

You'll want a few inches of stone under and around a molded sump pit. Use a perforated one since you don't have drain tile. Wrap it in drain cloth so you dont get silt carried in. Pack #57 stone in the void up to the bottom of the slab. Top it off with concrete.

JACKEL 17 in. x 16 in. Perforated Sump Basin SF15-DR - The Home Depot

The SF15-DR is the perfect basin for crawlspaces or where space is limited. Factory perforated with 40, 5/16 in. holes that allow for a quick reduction of standing water in crawl space areas, yards patios

www.homedepot.com

 

[TheOldHokie]

I have thought of that. As much as I don't want to do it it may be the best solution. I'd make a 18"-24" diameter hole and go down 36". Fill it mostly with stone and install the pump on that.

Then don't do it. Sounds like this is just a rain event problem.

Speaking from experience hydraulic cement will seal the crack from the inside and stop the intrusion. It sets very fast and as has been noted can be messy. The main advantage over other types of sealants is it can be applied on the inside wall and will set and seal while the leak is active. Been there, done that, and it works. Parging or otherwise waterproofing the exterior wall is the proper fix.

If you have a persistent standing water problem outside the house fix it outside the house. French drains are the standard way of dealing with that.

A sump pump is not a fix for any of this. Its a PITA workaround for a chronic water table or drain backup problem.

Dan

 

[The Evil Twin]

His description sure sounds like a chronic groundwater problem. His land is sloped, downspout piped way....