I live near the top of a mountain in Nova Scotia. Topsoil up here can be very thin in places--sometimes as little as inches. Anyway, while digging the hole for a pier foundation, about three feet down I hit smooth hard rock that seems flat. It's either a big boulder or bedrock. Now, the frost layer in Nova Scotia is 4 feet. My question is should I try to drill deeper into the stone or just set the pier foundation on top of it? Any expert opinions welcomed.
Hit boulder or bedrock. Should I keep drilling?
Started by
Star Trails
, Jun 06 2023 07:58 PM
5 replies to this topic
#1
Star Trails
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topic starter
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Mariner 2
Posted 06 June 2023 - 07:58 PM
#2
lovejaca
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Explorer 1
Posted 06 June 2023 - 08:21 PM
No reason to go any deeper if you are convinced it is a large bolder or ledge. Just be sure to mechanically attach your foundation to the rock.
- redskynj likes this
#3
FRANKVSTAR
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Viking 1
Posted 06 June 2023 - 08:22 PM
Not an expert, but I would think if you can wallow out the hole to get a clearer idea of the size of the rock you hit, I would think pouring concrete onto that rock would be a good idea,assuming your not mounting over 100lbs on your pier.
My thoughts are the rock or bedrock has been in the ground for decades stable as it is, and with concrete attached to it , you would come near to the perfect weight that others say the base should be, about the size of a concrete block 36x36x36. Making that by hand it difficult and takes a lot of bags of concrete or a concrete mixing truck dropping off a big load of concrete. I figure you may find that your pier in the concrete attached to that rock o bedrock underground would act as the same principle.
Again I am no expert and I live in South Carolina where it does not have a frost layer below 14 inches.
- Jim Waters likes this
#4
Stevegeo
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Vanguard
Posted 06 June 2023 - 08:34 PM
That rock has probably been there a few hundred thousand years , so you set your form on it, rerod then pour concrete on top.. its not going anywhere.. your pier will be there many yrs after youre gone.
#5
speedster
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Vendor - Telescope Piers
Posted 07 June 2023 - 03:12 AM
Can't beat a good rock. Drill some holes for rebar, epoxy them in (or grout) and you're golden.
- archer1960 and Astrola72 like this
#6
archer1960
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Mercury-Atlas
Posted 07 June 2023 - 07:36 AM
Can't beat a good rock. Drill some holes for rebar, epoxy them in (or grout) and you're golden.
Renting a hammer drill and drilling a few holes is a LOT easier than digging a hole...
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