Hello,Mike Bluenose here, I am new to this forum . If I have missed any important details please let me know. I want to build a workshop 16′ * 32′. The area where I will build is on granite bedrock that is sloped. I would like to build a wood floor so it is not so hard on the feet and knees. I am looking for suggestions on types of foundations suited for bedrock.
Edited 6/27/2008 6:33 pm ET by mikebluenose
Replies
I would think piers would be one way, though you better ask an engineer. They're going to have to be tied to the bedrock somehow.
I recently did a basement on some really nasty bedrock. Plans called for 2 #5 rebar continuous with dowels drilled into the rock every 48". We formed footings by staking 2x8's with chunks of rebar drilled into the rock. then we scribed plywood to the rock. You can also use reinforced plastic or a product like Fast foot to prevent concrete from spewing out too bad. Once you got the footings you can use the form system of choice. The one I did had a lot of steps. Rather than trying to form steps to fit the blocks, we used ICF's and ripped them to fit the footings. It really worked out pretty well. But it was a lot of work and a lot of head scratching.
"I am looking for suggestions on types of foundations suited for bedrock."
Reinforced concrete grade beam foundation walls pinned to surface rock - concrete slab with sleepers.
Jeff
A little bit more detail may help here.
Might be helpful to click on that "Update Profile" button top left of the screen next to logout. Knowing a general location helps. Your background helps too. Whether there is an AHJ (Authority Having Jurisdiction) which will make you do things, no matter what we suggest.
Now, you say sloped, how much across the 16' and how much across the 32'?
If it's only a foot ore two across either of the dimensions, a perimeter foundation beam doweled to the rock might suffice. That might is critical. Your AHJ might require either a foundation below frost depth, or an engineer's stamp, or both to do that.
Not all bedrock is the same, either, for what that's worth. Granite hold differently than limestone, both are different from bassalt, too (knowing which might suggest how many drill bits to invest in too <g>; or a rock drill <aiaiai!>).
Sometimes all it takes is a few hundred invested in an engineer's time.
re:bedrock foundation Thanks for your response,I appreciate your your patience. My location is Halifax ,Nova Scotia. I am a carpenter contractor.New to Halifax and to building on bedrock.Slope on 16' side of area is zero to 28", opposite wall is zero to 38", across high side of 32" grade is pretty even.
Halifax, Nova Scotia
Ah, well then, that explains the "bluenose" part then.
It's my understanding that each Province sets building standards, andthat some Canadian building code can be tough.
So, your first place to look may be online looking for who ever is your AHJ, as they should have rules available for what you will need for foundation work (permits, plans, wet-stamps, inspections, etc.)
You will probably have to be about 8" out of the ground on the high side, so that makes 38 + 8 = 46" which really suggests to me some sort of stepped foundation, rather than a continuous sort of beam. Now, a person could go in block up to level (remember to specify foundation steps in whole block modules). Or, a person could frame a wall up to the floor elevation to carry the floor joists.
Given the sizes, it would be tempting to use concrete plank, if car storage was contemplated. But, that's back to finding a decent engineer in the area to talk to, as being "smarter" at this than some hack archt in Texas.Occupational hazard of my occupation not being around (sorry Bubba)