Footings Directly on Rock

[tester]

I'm looking at a piece of property that is quite unique in that it is rocky. The rock is solid, not loose but is certainly not even. I was reading about the possibility of building by pouring concrete piers and tying them into the bedrock. I wonder if anyone has experience with this technique. From what I read it involves drilling and setting re-bar with apoxie then pouring in forms over the bedrock.

[rwanders]

That would be the method I have always seen or used. You should try and drill holes at least 8-12 inches deep in the rock. Really not a bad job if you rent a heavy hammer drill. All your holes will be down so the weight will make the job faster and easier. Holes 1/4"to 3/8" bigger than diameter of rebar will be good and won't require a lot of that expensive epoxy to bind them.

[ChrisVJ]

Better still make it a continuous foundation. My house is mostly on solid rock (granite) Drill every 12 to 16" and use 3/4" rebar cut to 2" below the top of the wall. Horizontal every 12" in 1/2" and two 1/2" Hor. about 3" below the top too. Just roughly scribe the shuttering to the stone. Don't forget ties at least every 8' for the plates. Best is an 8" wall. Compared to footings etc, easy peasy.

Afterwards line the wall with 2" of rigid polystyrene. If the rock can get damp best to lay a sheet of heavy duty poly sealed to the edges too.