I have an ocassional leak problem in my basement. I get a leak that comes from floor crack in the basement. It is the only place in my basement that I have a leak. The leak can come when there is a heavy rain or a quick thaw of snow. The wall that the leak occurs on is adjacent to my 2-car garage. I have been able to reinact the leak by running water on the far side of my garage. In about an hour I will have water in my basement.

My question is "how is the water traveling under the garage floor?". And is there a way to fix it? Will replacing the garage floor solve the problem?

Is the leak in the wall, at the junction of the wall and floor or is it in the floor itself? What is "occasionaly"?

It is always quick and easy to use a hose as a demonstration to show where the water leaks in, and ONE source, but the cause and path can can be different. Since it is also related to a relatively short spring thaw, there could be other souces to the basement that that a hose does not show.

Just some possiblities based on the info without seeing the problem personally -

You have discovered one source of water, but there may be others. -

If the water in the garage shows up relatively quickly that far away, it is probable that you have very permeable fill under your slab (which is good). Somehow, it gets under the home's footing (possibly through granular fill from over-excavation or where there utility trenches). Water wants to go down, but does not always fllows the shortwst path.

You apparently have some moisture under your slab, or there is an impermeable soil/bed rock that lets it accumulate until it finds an exit.

I doubt you have enough water in the garage to cause a habitual leak, so just replacing the slab immediately would not be necessary.

Alt5hough it is a very temporary measure, you could clean out the crack and depending on the width. Depending on the crack width, use either hydraulic cement (wider crack) packed into the crack or try to caulk with a quality fexible caulk. I do not not like temprary patches, but they are easy and cheap and can help in diagnosing the real problem. It sure beats digging up everything to put a temporary patch on the outside. - If it works, then you have eliminate the easiest poit of leakage!

Live with the temporary fix and do your water test and observe a few heavy rains to see if it did any good. If not, you will have to explore further.

If it is coming from a crack in the floor, it is obvius you have excess water under the slab and probably not just a wall leak. - Often diagnosing takes a few steps, which give you a chance to think instead of jumping into more than you should.

If this does not solve the problem, look around for a professional to determine where the water is coming from, before jumping to a combination diagnoser/contractor. It may cost something initially, it could be far better in the end if you really know the source and cause. I respect the opinions, experience and local knowledge of many waterproofers, but unfortunately, advertising offers can cloud the situation.

Anybody on the forums can only give opinions since thaey do not have an oppourtunity to see the real situation, drainage and quality of construction.

Good luck and post back on progress and future questions.

This message has been edited. Last edited by: concretemasonry,

Replacing the garage floor will likely have no effect on your water problem. There are two possible culprits, based on what you've posted...either the garage foundation wall, or the basement wall which abuts the garage. Waterproofing the garage foundation should be easy and inexpensive, because the wall is probably only 3 to 4 feet deep below the ground. If you do that and it doesn't solve the problem, then the basement wall can be waterproofed by sawing out a narrow strip of the garage floor, and exacvating and waterproofing the bsement wall, and then patching the garage floor.

I'd be willing to bet that the garage foundation is bare block, and wasn't parged or dampproofed. My fall-back position is that it was parged but not dampproofed. However, it's also possible that the water is flowing below the garage footings and finding its way to the basement wall. If that's the case, there's no need to waterproof the garage wall.

As concretemasonry has said, all we can do here is basically guess.

Scooterbear -

I had no idea of the climate (affects the depth of footings) or whether the garage was at the first floor level, down a few feet or a "tuck-under". Homes with step foundation levels usually have loose backfill at the elevation changes that wil permit moiture transmission.

Richard has a good point of the garage foundation permitting moisture in until it finds a point to enter. A waterproof foundation can prevent leakage, but water seems to looks for other ways if it is diverted. Determinng the source can onlt be done by being there and patching the interior leakage point is often a realtively temporary solution if you cannot eliminate the source (drainage, grading, long extensions, etc.) is the first thing to do.
Your first guess was pretty good since it showed that the water got under the slab relatively quick. There could also different area that will alow the water to get there just a little slower.

Some leaks and the sources of water take some time to discover even after the point of interior leakage is known.

I had 4 level home (on a side slope and clay soil) where the water source was from the garage that cut a natural drainage path and directed the water back about 40 feet through the backfill and along the footings until it reached the lowest level. Typically, the leak would start about 4 hours after a big rain. Because of the location and obstructions, I had no choice, but bite the bullet ando install interior drain tile with the help of my 12 year old son. He and his buddies carried out the concrete chunks and dirt and hauled in the rock weekends for a few week-ends.

Make sure you understand where the external water is coming from. If you cannot that, you are faced with with correcting the leaks possible. Many people that have some predictable water and do not intend to finish the area chose to live with a occasional, predictable problem rather than spending a fortune.

Thank you to both for your input and advice.

My home is in Wisconsin. The leak is at the junction of the floor and the basement wall. The leak is in the same spot ever time. It appears as a small trickle that runs to the basement dream. My basement is finished. But I have it torn up int that area trying to determine where the leak is coming from. The basement wall shows no evidence of cracks.

The basement and garage walls are poured and not block walls. The garage wall is probably a 4 foot wall. My house is a ranch on level ground. I have re-landscaped and increased the grade around my entire house. The side of the garage has a slight grade, but during heavy rains, standing water tends to build up on the ground on the side of the garage.

What kind of a professional will determine the cause of the leak? I had one company come out and try to sell me a sump pump. I am not keen on that idea. I would rather stop the water than to just keep sucking it up the 4 - 6 times a year that it happens.

So I am leary of calling another contractor and have him trying to make a sell versus identifying the cause of the problem.

Thank you for any additional advice.

In a concrete wall, it may be only a tie-rod hole that is leaking, or it may be a crack on the outside which isn't visible inside, although there won't be any block cores for the water to accumulate in. It could be a small local failure of the wall or of the dampproofing on the wall, if any. Such failures can be caused by backfill which includes large rocks or construction debris, or by tree roots, among other things. It is also not impossible that water is collecting under your basement floor and entering in that spot, but it is unlikely.

Depending on the ground water conditions where the building is located, water may be entering the garage wall or flowing under its footing, and travelling in the soil to the basement wall. Maybe the builders did not think that the basement wall needed to be dampproofed, because they thought of it as an interior wall, or maybe it was and the dampproofing has failed. If it the "modern" thinly-applied spray-on stuff, it's a failure waiting to happen.

But the question is, what to do? I don't think you'll find one professional in a hundred (meaning architects or engineers) who can properly diagnose water in basements. If I were you, I would look for a foundation contractor, and weigh what he says against what concretemasonry and I have written here. Those are our best guesses as to the possible causes and possible remedies.

I know that it is possible, for instance, to remove about 18 inches of the garage floor, and excavate and waterproof the basement wall, but that wouldn't be my starting point.

I would do another hose test, all along the garage wall, starting at one end, and moving very slowly (like two hours between moves) about six feet at a time, and see if this pinpoints the spot where the water gets to the basement. If you can narrow it down to one spot, then your problem is right there, and it's an easy fix. If water gets to the basement no matter where you put the hose, then it might be the whole wall, and I would excavate one spot to see whether it was ever dampproofed. If it wasn't, I would try excavating that whole wall and waterproofing it. That's still not a horrible expense.

If those steps don't solve it, then the culprit may be the basement wall.