Paver Patio Drainage


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Old 03-19-09, 05:59 AM
J
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Question Paver Patio Drainage

I'm planning to install a paver patio and have a question about drainage. The patio will be 24' long (against the house) and go 20' out from the house. I plan to do a 2' high sitting wall along the entire patio length opposite the house. I will be using 6" of base material and 1" sand under the pavers.

The backyard currently slopes slightly away from the house to about where the sitting wall will be, then it goes uphill rather quickly from there (essentially forming a swale at the proposed location of the sitting wall).

My question is, since the patio will slope away from the house toward the sitting wall, do I need to anything special for drainage where the patio and sitting wall meet? I already plan on burying a drain pipe on the other side of the retaining wall to move the water coming down off the hill, but what happens to the water on the patio which runs toward the wall? I don't want to end up with puddles up against the sitting wall!

Thanks!
 
  #2  
Old 03-19-09, 06:20 AM
B
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First, where are you? If your ground freezes in winter it makes a big difference. look at your entire property and decide where the water MUST end up. Some soils are so well drained that there will never be a problem no matter what you do (almost). Other soils are worse than concrete. Called water impervious soils, the last one I tangled with was left by the glaciers, big ones, and water would never soak down through that stuff.

Allowing for frozen soils and winter lifting by frost, you can easily plan for a path for drainage and have patio instead of a pond.

Let us know,
Bud
 
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Old 03-19-09, 07:04 AM
J
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I'm in PA, so yes the ground definitely does freeze. The ground is made up of mostly shale. The way the property is currently graded, the water runs into the swale and to the left (looking out the house into my backyard). Sometimes when we get lots of rain the water does sit for a little while right where the sitting wall will be, which is why I plan to do the drainpipe behind the wall and run it to the left of the property.

The water which is on the patio is where i'm confused - how does it drain off if the sitting wall is up against the patio?
 
  #4  
Old 03-19-09, 08:07 AM
B
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You can create drainage holes/tunnels under your sitting wall, however, you probably won't be able to rely on underground drainage on the other side as it will freeze solid in PA. Your patio may also lift as much as 6 to 10 inches out away from the house. That pitches the water back to your foundation if you do not allow enough slope. In about a week or two the snow and frost will disappear from my lawn and my camper will be left almost a foot in the air as the frost under it will be the last to go. I can't tell you how many parking lots I've seen installed on the level that turn into ice rinks every winter. In PA your frost line is probably 3 feet down so any drainage will be subject to freezing above that. Allow for the frost and plan all of your drainage for the surface.

Good luck
Bud
 
 

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