Garage floor & water.. Need suggestions.

[WesPete66]

I have a problem with water getting into my garage/shop floor and need help finding a suitable repair..
My garage is about 28' x 28'. The ground soil level on 3 sides is higher than the floor level. I have a recurring problem of water entering around the walls, and in a wet spring through a crack in the floor.. I now know that it was built with a slab type construction, they poured a full concrete slab & then built up the concrete block on top for the walls. (footings etc is a mystery) And now of course water enters under/around the concrete block....
What can I do to remedy this? Here are some things I'm considering, what would you do??
1. Remove the soil against the block & apply a tar sealant?
2. Remove the soil against the block & install styrofoam panel material?
3. Remove the soil against the block & pour a thin (3-4" thick ?) concrete barrier?
I'm hoping you will have suggestions for me. Thanks for the help!

 

[MozamPete]

I would go with option 1, but then add a French drain (basically shingle inside an water permible Geotech fabric sock) around the perimeter on a 2% gradient to drain any ground water away.
Yes, concrete is not waterproof and will absorb/pass water through - but only if the water is standing there with nowhere else to go. If there is a drain to alow it to flow away the water will take the path of least resistance and problem solved. At least that has been my experience.
Trying to seal the concrete and leaving the ground water there will always eventually fail.

 

[Bob Korves]

Every example is different, but basically you need a way for the water to drain by gravity to daylight without passing through your shop along the way.

 

[David S]

Is the ground graded away from the wall? You mention water coming up through a crack in the floor. Are you sure it is not a water table issue, i.e. water level rising in the spring?

David

 

[tweinke]

I would go with option 1, but then add a French drain (basically shingle inside an water permible Geotech fabric sock) around the perimeter on a 2% gradient to drain any ground water away.
Yes, concrete is not waterproof and will absorb/pass water through - but only if the water is standing there with nowhere else to go. If there is a drain to alow it to flow away the water will take the path of least resistance and problem solved. At least that has been my experience.
Trying to seal the concrete and leaving the ground water there will always eventually fail.

I would think this would be the best approach, sealing the wall only may help for awhile but the water needs a place to get away from the wall.

 

[brino]

How far below ground level is the floor? Are we talking inches or feet?

Start with the easy stuff first:
Is there eaves-trough on the roof with intact downspouts that empty many feet away and downhill from the outside wall?
Does the surrounding terrain drain towards the building?

The full best solution is likely removing any surrounding soil that is higher than the slab _and_ putting in a drainage tile around the outside.

Another (though maybe costly) idea is to pour another layer of floor slab on top the one that's there. You do have to empty the space, but if you only need a couple inches it could help and would get rid of that crack too. The exiting block walls could act as forms for the new slab.

-brino

 

[Cheeseking]

Well I would definitely do #1 & 2 plus a gravel base with french drain tile (the corrugated black plastic tube) around perimeter or offending wall. Pitch to somewhere away from wall where it can drain. Silt screen on top and backfill. Make sure downspouts are directed away from the foundation as well. Yep its going to be a big project and likely expensive unless you have a lot of free weekends and can tackle yourself. Sounds like a summer or fall project. If you do it in spring I'd hire it out, or get some help so it can be banged out quickly in a spell of favorable weather. My garage floor slab also has sunk 3" in the center and collects water. It drains within a day but kinda stinks in winter with salt and slush. Im considering having it "mud jacked". Would love to have it all ripped out and fix the problematic sub base areas and redo the slab but at $10-12/sq my wife probably wont buy in

 

[juiceclone]

from your pdf. file I see outside soil is almost 3 course of blocks high....that ain't a garage, it's a basement. Yes on the drainage pipes and seal around the bldg, and probably a sump and pump to get the water someplace else! At first I thought just pour more concrete raising the floor level, but that's out...too much.

 

[RJSakowski]

The foundation of our 100+ year old house is made from porous limestone and sandstone and I had a wet basement. Heavy downpours would result in water running down the inside walls. Here is what I did to eliminate it.
1. I poured additional concrete leaving a 3" x 3" moat around the perimeter leading to a drain to the outside. This prevented water from accumulating in the floor.
2. I landscaped the area around the foundation so it sloped away from the foundation. This directed most water away from the foundation.
3. I installed new guttering on the roof. This directed the water from the roof away from the house.

This has resulted in a dry basement

On another building, the seepage under and through a block wall was so bad that the wall failed. I rebuilt the block wall but filled all the cavities with concrete, resulting in a dry building.

There are coatings available which are guaranteed to seal a foundation wall against seepage. In your case, it may be a part of the solution. If the conditions permit, laying drain tile to drain away any accumulated water will help as well.

Finally, I watched an episode of "This Old House" where they had a severe problem with water ingress and I believe that they used hydraulic cement as a barrier. I think this was the episode: https://www.thisoldhouse.com/how-to/hydraulic-cement-leaky-basements

 

[FOMOGO]

Drainage is king regarding these kind of issues. I owned an excavating co. and dealt with these issues on a regular basis. Most problems are due to poor site planning, but once the building is there, you have to deal with what you have. If as in your case you have ground above the floor on one or more sides, the best, and often most cost effective cure is to create swale's (a low area created out beyond the drip edge of the roof that create a path for drainage away from the building). Trying to seal out water is generally a stop gap measure that meets with marginal success, but used in conjunction with good drainage can certainly help. As RJ said above, gutters and extended down spouts will also help. Like most problems you have to look at the big picture. Mike