[LadySam]

I am in the process of removing and replacing a brick patio that was 1-poorly done (many gaps) and 2-in disrepair.
I have done some research and asked a round and have heard differing depths to lay the crushed gravel and layer of sand, anywhere from 4 to 8 inches.
Quite frankly this old lady is sick of digging and moving dirt.
If I am going to do it properly what would be the proper depth in order to insure a stable patio?
Also, I should have a 2 inch layer of sand underneath the brick and the rest should be crushed gravel underneath that? Is this correct?
Thanks in advance.

[ma0641]

A lot depends on where you are located. In the Atlanta area, 1-2" of paver base and 1" of sand works well. In Minneapolis it will frost heave. Where are you located?

[LadySam]

I'm in North Carolina, we have some pretty wacky weather if that matters. The area is also in a part of the yard that will catch quite a bit of rain, part of the reason I am repairing it is the way it sloped much of that rain went toward the house. I know I will have to put a slight slope so that it will drain away from the house, not sure if the fact that the soil may be wetter there makes a difference, I just want to get it done right the first time, no do-overs (I hope)
Thanks so much for your response

[smearcase]

I wrote a detailed response and lost it but here are the things I was trying to stress.
A patio with porous stone under it is clear path for water to destroy the foundation and in my case the ends of about 10 joists in the crawl space.
Mine was loose laid bricks placed on a concrete slab and the slab had been built level instead of with a significant slope away from the house.
If you have loose laid brick, the slope of the brick doesn't matter as the water will saturate the stone and depending on how well the water in the stone can get away from the house.
I had to install a perforated pipe surrounded by stone on all sides well below the concrete slab and near the house before I got rid of my water problem. Hole perforations should go down, not up.
The lay of the land beyond the patio is a big factor. If you have wet soil there now, that is not a good omen.
The slope of the ground before the stone is placed is critical and consider placing polyethylene and/or a close knit filter cloth on the earth base before placing stone. The stone needs to have an exit (daylight) at the outside borders of the patio or it will be a sponge especially if you have a constant wet area now.
I don't know how closely your conditions are to the one I experienced but if I was doing it again, I would definitely install a catchall/fail safe drain pipe near the house--and there again there has to be a suitable position you can take it to and still keep the water going away from the house. Instead of a slight slope I would use the steepest slope I could tolerate-well beyond
1/4" per foot if possible. You could also consider mortaring the bricks or maybe that is what you have now. Aluminum flashing in an 'L" shape at the house can also help.
I hope I haven't confused you too much but the amount of water coming off a patio can do much damage if it goes the wrong way. I repaired my joists myself and if I had had to hire a contractor it would have cost me probably 10k or more working in a confined crawl space. That is what is causing my abundance of caution here. Hopefully you have a better situation than I am picturing.

[LadySam]

Likewise, I had typed up a rather lengthy thanks and response, then bam! Connectivity Lost.
You have certainly given something to think about, unfortunately this house was built very low to the ground, not much crawl space but after reading your post I'm thinking it would be a good idea to take a look under there just to be on the safe side. I got to say, I'm dreading it.
Drainage is a problem there at the moment, but the guttering needs to be redone, so hopefully that will take care of some of that.
Thanks for the idea about the perforated pipe, I had tried to figure out what to do on the sides that are next to the house, I think that would work.
Is this something that is pre-made that I can purchase, or could I fashion it myself?

[smearcase]

I dug a trench about a foot below the concrete-would be below the bottom of the stone if you used stone and this stone would be individual crushed rocks each about the size of a ping pong ball (designation is #57)-not a lot of dust and smaller stones that choke the stone up and stop the travel of water--
I put the trench about a foot away from the house so that the stone wasn't right against the foundation.
The pipe was just perforated 3 or 4" pvc or plastic readily available at home supply stores, often comes in coils, black.
I used the same method we used in highway construction, A few inches of stone under the pipe, then the pipe with the holes down so that water will leave the trench faster as it builds up in the bottom of the trench. Then a few inches of stone along the sides of the pipe and maybe 6 inches over the top.
The trench needs to have a good slope (the more the better but min. 1/4 or
3/8" per foot) and the outside end of the pipe and the stone under it (water will flow mostly under the pipe and only in the pipe when it builds up due to heavy imput-may never flow in the pipe) should be open and kept open. .
The existing ground will control where you outlet the pipe (pipe and stone under it must have free flow where the water exits and this may be difficult to achieve (could reauire a long run of pipe or maybenot feasible) depending on the existing slopes around the patio border.
A french drain (no pipe and no outlet) which could be just a stone filled trench could also be considered. It is just a stone filled trench that can store some water which will gradually seep down into the soil but relieve some of the pressure that would go toward the foundation.
I am out of time right now. Good luck.

[LadySam]

Yes I have seen those in my local home improvement store.
Great idea, sound like that will work fro me.
I'll let you know how it goes.
Thanks for the help, much appreciated.

[smearcase]

If I were building a patio from scratch I think I would get an estimate for a concrete slab with a "stamped" surface which can be made to look like brick or stone or other patterns, and even different colors with admixtures. Or maybe a properly sloped concrete slab with brick mortared (just like a brick wall laying on the concrete slab). Might need a bond breaker between brick and concrete to prevent different expansio/contraction problem possibilities and some wire mesh in the concrete to deter cracking. And some good seals where the slab abuts the house.
Any design that allows water to penetrate to any degree into the soil near the house foundation is as bad or worse than clogged rain gutters or maybe even no gutters.
Have someone inspect the inside basement or crawl space adjacent to the patio to determine if there has been any problem to date. I was lucky to catch my problem before it could have caused a very expensive (even dangerous) failure.