Below is the layout of my patio and the context
The patio settled and now moisture collects at the base of the wall causing efflorescence on it and small cracks in the cement coating at the base of the wall. These creack seem to be always wet …
As you can see there is a raised deck on the patio and the main problem with this is that the excavation needed for a french drain will reach the base of the 4x4s that support the deck platform.
The french drain will be installed under the patio like in the picture below and after that the pavers will be reset
At this point I have two choices:
1) dig along the wall and stop when I reach the first 4×4
2) dig 2 feet away from the wall and go all the way under deck to the garage
Which solution would you recommend?
The area between the deck and the garage has no water problems
For a full size picture click here
Best Answer
If you're going to pull up pavers to install a french drain, you might as well just pull up all the pavers and get the slope correct instead.
A well laid patio should naturally shed water via its pitch. The ideal solution is to pull up the pavers, re-grade the base layer (should be sand directly under the pavers) and then lay it all back down...perhaps with a slightly exaggerated pitch this time.
If you insist on a drain, I wouldn't bother with a french drain and instead consider a surface drain:
It'd be a lot easier to install.