Flooding into garage at base

[tbgallant]

Hey guys,

So now that the frost has set in, I'm getting water collecting at the base of my garage (slab construction, top of slab not very high off grade, maybe 2-3 inches) when it rains (cold spell and then we get a warm spell with lots of rain).

The backyard is sloped towards the garage (I didn't build the garage, previous owner should have known better and built slab higher).

In the spring/summer/fall any heavy rains are handled ok, the water soaks into the ground and doesn't collect at the base.

But it is winter, we have had a good cold snap and there is plenty of frost in the ground. This week we had a warm spell with some heavy rain. The water has no where to go now, and just collects at the base of the garage, and then leaks in under the sill.

I'm thinking a french drain won't really help here, as the ground will freeze regardless and the water still has no where to go.

Suggestions?

I'm considering digging a hole big enough for a 5 gallon bucket, sink it down so the top edge at is at the point I want to limit the water level (2" from top of slab) and just drop in a sump pump when I am concerned (when they are calling for any amount of rain basically).

Thanks

Tim

 

[chrisexv6]

Dig some of the ground away from the slab area, maybe 2" or so (basically get rid of the layer of grass to get to dirt). Get that rubber pond membrane stuff....glue one side to the concrete, and run it off the concrete into the yard (4' wide roll would do well). Make sure it has some sort of grade away from the slab. Cover in landscape stone (white, multicolor, gray, whatever you like). Water wont easily run uphill, so if its coming down from the yard it shouldnt be able to get in. If its rolling down the side of the garage, it should then go down the little grade you just added and out in to your yard. Another option is to add 4" corrugated (black) pipe along the edge of this membrane setup (run the membrane under the 4" pipe to help it stay and provide extra drainage if the membrane somehow gets flooded with water), and you can buy drain grates that attach to it. The drains will be level with the yard (you can see the openings) so regardless of if the ground is frozen, the water will end up in the drains and follow the pipe, you then just need to make sure the pipe is pitched and it drains far away from your garage.

I saw all of this done on a web page somewhere, and its beyond me what I ever did with the link. It was very detailed and very well done, I wish I still had it somewhere.

-Chris

 

[tbgallant]

Hey Chris,

Problem is I can't create the grade away from the slab, the back yard slopes TOWARDS the garage. I can't raise the garage.

Add the corrugated black pipe just level with the surface of the ground and then sloped towards the driveway is an option, but will be a lot of digging. Guessing this may be the long term solution.

Anybody have any thoughts about the sump pump idea for short term?

Thanks

Tim

 

[chrisexv6]

I know the yard slopes toward the garage, what you would end up doing is sloping as much you can away from the garage and push the low point between yard and garage more away from the slab, even if its only a foot or so. How extreme is the slope to the garage? Do you have pics?

The sump pump idea will work, I actually did something like that on the foundation problem I had......the water was running (by itself) into a nearby window well. Dropped the pump into the window well and ran a 50' hose out to my back yard. When the well filled up I engaged the pump (it was cold windy and rainy, didnt setup the check float).

You may find you need more than one pump! How high is your water table? If its high and you dig down for the bucket you could release the water table and make more problems for yourself. How about digging a 4" wide trench at the base of the slab, slope it away from the garage and drain it off somewhere else? Pics would help so we can see where the slope from the yard interacts.

-Chris

 

[russlaferrera]

What about a "Speed Bump" in front of the door/garage. The water flows toward the door. Diverting is the only way to keep it from coming in. A trench will fill. The cost of a pump, the operation plus freeze protection, and where to pump the water to is a consideration.