I have to bridge our main drain out of the back garden at 3 points where it crosses new foundations. So each area requires special underpinning = dig out 200mm under the drain and lay concrete 400mm each side of the drain.
So there will be 800mm width of concrete at a depth of 200mm under the drain. I will then lay the foundations as normal up to the side of the drain.
I would like to know if it is ok to lay the small underpinning sections of foundation the day before i do the main pour. I just feel it will be much easier to have gotten these 3 sections poured and in place before i do the main foundation. I would make my own mix as well in the mixer. I don't need a huge amount of concrete for it as well.
Is this ok to do and could i place some steel threaded rod into the concrete projecting upwards so it binds to the new concrete the day after ?
So there will be 800mm width of concrete at a depth of 200mm under the drain. I will then lay the foundations as normal up to the side of the drain.
I would like to know if it is ok to lay the small underpinning sections of foundation the day before i do the main pour. I just feel it will be much easier to have gotten these 3 sections poured and in place before i do the main foundation. I would make my own mix as well in the mixer. I don't need a huge amount of concrete for it as well.
Is this ok to do and could i place some steel threaded rod into the concrete projecting upwards so it binds to the new concrete the day after ?
