I recently saw something about thermal bridging, not sure your plans for heating but if you insulate the rock and then pour sand on top of the insulation you can have a good mass of warmth in the winter. Concrete with radiant pipe on top of the sand. Not sure your plans but it might be useful with your climate
When you pour, use multiple lifts. Don't go up all in one shot. You want to limit the hydrostatic pressure. This was how I poured commercial pole bases -- to stop blow-out. After the first lift -- say 15" -- let it set for 30 to 40 minutes -- and while it's still thoroughly wet -- pour a second lift. I'd high pressure wash the bedrock so as to get an ideal bond. I'd punch holes in the bedrock and set epoxy bonded rebar vertically so as to absolutely bond the primary layer. You ARE in ice country. You don't want ANY water to weep in and then ice up and lift up the whole she-bang.
Good info thank you. We ended up pouring the whole place in 3 lifts. The first was about 36” deep with no bulging or blowout whatsoever. The icf forms are quite strong. We did not pressure wash the rock but did wash it with high pressure fire hose 2”. We installed 15m rebar dowels 8” into the rock and 36” into the wall and epoxied every 4’ on centre. The actual footing will be about 56” below finished grade when we backfill so freezing is not an issue in our location.
I recently saw something about thermal bridging, not sure your plans for heating but if you insulate the rock and then pour sand on top of the insulation you can have a good mass of warmth in the winter. Concrete with radiant pipe on top of the sand. Not sure your plans but it might be useful with your climate
When you pour, use multiple lifts. Don't go up all in one shot. You want to limit the hydrostatic pressure. This was how I poured commercial pole bases -- to stop blow-out. After the first lift -- say 15" -- let it set for 30 to 40 minutes -- and while it's still thoroughly wet -- pour a second lift.
I'd high pressure wash the bedrock so as to get an ideal bond. I'd punch holes in the bedrock and set epoxy bonded rebar vertically so as to absolutely bond the primary layer. You ARE in ice country.
You don't want ANY water to weep in and then ice up and lift up the whole she-bang.
Good info thank you. We ended up pouring the whole place in 3 lifts. The first was about 36” deep with no bulging or blowout whatsoever. The icf forms are quite strong. We did not pressure wash the rock but did wash it with high pressure fire hose 2”. We installed 15m rebar dowels 8” into the rock and 36” into the wall and epoxied every 4’ on centre. The actual footing will be about 56” below finished grade when we backfill so freezing is not an issue in our location.