My house has a concrete patio (about 16x16 though its 5-sided) which is not sloped properly for drainage. In some sections it seems basically level, in others (near the doorway of course) it actually pools water.

The worst area I estimate slopes about 1/8" per foot the wrong way.

The concrete itself is in excellent condition. It doesn't show any signs of settling, I think it was just not poured with correct slope in the first place (*).

I am planning to deck this over with sleepers laid over the concrete. S the concrete appearance is not very important.

Ideas how to deal with the slope:

  1. (CAN'T DO) Pour some leveling compound - height by the doorway is already very tight, can't afford to lose any of it

  2. (POSSIBLE) Grind 8-12" wide channels to achieve at least 1/8" per 1' slope, from the low spots to the yard. Rent a grinder like the example pasted below. Concern: might have to grind off a lot of material, maybe this is not practical.

  3. (POSSIBLE) Cut channels with a diamond demo-type saw with correct slope. Cut as many as needed. Concern: thin channels may clog with time.

Are either #s 2 or 3 feasible? Am I missing anything important, or is there another option I'm ignorant of?

(*) I think this was bad planning, not a construction error. This area was once covered and not exposed to much water.

enter image description here

  • How long is the section that slopes 1/8" per foot the wrong way? – JACK Aug 16 at 15:50
  • @JACK that area is about 6-8' across, its sort of an oval. It, and the door, are in one corner of the patio. From the door to the yard is about 16'. – UuDdLrLrSs Aug 16 at 15:51

Grinding or cutting channels would be really hard. Some spots they's have to be up to an inch deep. I would drill a few 1/2" holes in the concrete where the water pools and let it just soak into the ground. You could cover the holes with a drain cover if you were concerned about the appearance.

| improve this answer | |
  • I like this thought... I don't know what's under the slab. Probably gravel and then our normal clay soil. I wonder how well that would soak away? – UuDdLrLrSs Aug 16 at 16:34
  • 1
    @UuDdLrLrSs Probably the same as at the edge of the slab... you could experiment. – JACK Aug 16 at 16:48
  • With sleepers and decking appearance won’t be an issue, I find drilling multiple 1/2” holes may take as long and still have issues plugging. surface grinding 8’ in a couple of places could be done with an angle grinder and cutting disk less expensive than renting that grinder for 1/2 day but by hand would take a little longer. I like to direct water away from the home even if no basement. – Ed Beal Aug 16 at 19:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.