I am looking for a solution to drain my patio which is sloped toward one of its corners. The size of the patio is 15'x 35'and the area is Toronto (for rain volume estimation)
I would like to drain my patio using a floor drain (4" diameter) connected to a 4" pipe that will be drained to a dry well that will be ~12' away from the corner in question.

Here is the link to the drain http://www.homedepot.ca/product/abs-4floor-drain/981915

The "standard" solution would be to use to use a catch basin (9"x 9") which looks too large to me

Is my solution acceptable?

Edit: this is not a reffering to the load that this drain can take Here is the setup, the drain will be hidden under a precast concrete slab that is the base for an offset umbrella

enter image description here

My this is the umbrella, attached with concrete anchors to the slab

enter image description here

  • Have you considered how you would clean leaves off the drain? Jul 8, 2015 at 18:53
  • Yes. The concrete slab that usually sits above the drain can be easily removed by holding the umbrella post and pivoting the slab around a corner (the north corner in the picture) That is a 10 seconds operation. The post is attached to the slab with concrete anchors (it has a cross case that is not represented here) see above. My slab covers the entire base
    – MiniMe
    Jul 8, 2015 at 19:28

1 Answer 1


edit: After reading your updated question, you will be fine installing the smaller drain. I have a large driveway drain that I installed a few months ago, and it works great to drain the huge puddle that used to form. I used a drain box similar to the 9x9 that you have, and 4" pipes. Occasionally, during a very heavy rain, it will get behind and not completely drain until the rain stops, but that is because the pipe itself is only 4"!

Great question! I am not an expert, but I would highly recommend the larger drain. The reason is, on a small drain, every time the drain gets stepped on (or driven over with a lawn mower), 100% of that weight gets put on your pipe underneath. A 4" pipe isn't designed to carry that weight, and could crack.

Even though the 9x9 drain won't necessarily drain any faster, it will have more surface area under it to support being stepped on, that way the soil under the drain, instead of the pipe supports the weight.

enter image description here

  • I am more concerned with the volume of water that this can take. The drain will be placed on a patio, in its corner. The corner is formed by two concrete blocks like the one used to build the curve. They are 1/4-3/8 of an in higher than the pavers on the patio so they naturally keep the water on the patio and they guide it toward the drain. Over this corner I have a precast concrete slab ..see the schematic representation added to the question body
    – MiniMe
    Jul 8, 2015 at 18:33
  • Above I meant the curb not the curve
    – MiniMe
    Jul 8, 2015 at 18:49
  • @user2059078 I'll update my answer tonight for you! Jul 8, 2015 at 18:51
  • How big is your driveway? What surface? Asphalt? Concrete pavers?
    – MiniMe
    Jul 9, 2015 at 13:19
  • Concrete, it's 12 feet wide, and about 40 feet long sloping to the drain Jul 11, 2015 at 14:50

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