Grading A Patio Located Away From House
Grading a Patio
I'd like to install a brick patio in my back yard and I'm not sure how to pitch it properly. The problem is my back yard has a slight pitch towards my house. The patio will lie about 25' from the foundation of the house. Because of this separation I thought it might be alright to have the patio pitch slightly towards the house, and I'm also thinking that since the landscape is pitching in that direction, why not the patio. Is this sound reasoning or am I all wet? Suggestions welcomed.
I have done a quick sketch for you showing how I would suggest doing your grading.
If your land is pitching towards your house, that is incorrect grading, and I am surprised that you don't currently have any water problems. Do you? At any rate, any recommendation I make will be so that your property is graded correctly.
My suggested options for grading your patio and prevent water problems are as follows.
1. Option #1 - Grade the land away from your house and grade the patio towards your house. You will then have created a lower area between the patio and the house elevation. In this area, create a swale and lead this water elsewhere. The swale will be pitched also. Visit this page for a more details and instructions. This will probably make it necessary to regrade the area on the far side of the patio also. Landscape Grading
2. Option #2 - Grade away from your house as above. Create a small retaining wall to raise the grade of the patio. Install a perforated pipe at the bottom of the wall to collect water and lead it away. The patio may be graded towards or away from the house. To clarify further, please see Retaining Wall Drainage
The pitch for the land away from the house should be 1/4 inch per foot at a minimum. In case you decide to change your mind about the patio location, a swale should not be located any closer to the house than five feet, although I am more comfortable with further out. The swale itself should also pitch at a minimum of 1/4" per foot (2%). I like this amount of pitch for the pipe also, although you can get away with less, particularly if it is the smooth PVC rather than the corrugated pipe. Also see my page on Perforated Pipe