Spa built 3 inches too high for standard rate for patio drainage.

drawing of spa and patio

drawing of spa and patio

My outdoor spa was built 3 inches too high out of the ground to meet code restrictions for drainage. The deck for the spa will connect to the back patio and the side of the house. The distance to the house and patio varies from 5-8 feet. Originaly they were going to put 3 inches of concrete over the patio, which code restrictions will not allow, since it brings the depth of the patio even to the door threshold. Now they plan to go with an overlay of about 1/2 inch on the covered patio instead and pour concrete the standard depth for stamped concrete on the rest of the deck.

Since they built the spa too high out of the ground, they will have to increase the depth of the drainage slope. Will there be too much of a slope for drainage to affect walking or to sit at a table with such limited space? Is there another solution?


I don't have enough information to answer your question. You need to know the finished elevation of the patio where it meets the house, the finished elevation at the end of the patio (in general since it varies) and the finished elevation of the spa.

Once you know this, you can determine the slopes to different area.

The slope would be determined by dividing the difference in elevation between two points by the distance. You will have to change the inches to decimals. So if the patio at your house, for example is 3" higher than the elevation at the spa you first must change the 3" to .25 (since it is .25 of a foot).

If the distance to the spa is 15 feet, you would divide 15 by .25 You would come up with .016 (1.6%) Acceptable slopes range from 2% to 5%. Some masons use 1.5% as a minimum, but I am more comfortable with 2%.

If the slope is not within this range, I would have to have even more information to figure out a solution so that you have proper drainage. The last thing you want is drainage issues.

I hoped this helped.

Click here to post comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Landscape Grading.

If you enjoyed this page, please share it!

Ebooks by Susan