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Can anyone advise on how extension foundation trench should be dug to butt up against our existing house foundations?
House is old 1800's, old footings for two story seem to be some compacted red brick/rubble, quite shallow, soil has a lot of clay.
New foundation is to be 1 meter deep, what is the best way to do this to butt up with existing old shallower foundations - I suspect not to dig straight down as it could collapse?
Do I dig out foundation at 45 degrees slope away from house foundation to bottom of trench to avoid collapse of old foundation? - but then new concrete footing in this section will be not as deep as 45 degree wedge of mud underneath?
I cant see a way to get all the earth out without risk of collapse?
cheers
House is old 1800's, old footings for two story seem to be some compacted red brick/rubble, quite shallow, soil has a lot of clay.
New foundation is to be 1 meter deep, what is the best way to do this to butt up with existing old shallower foundations - I suspect not to dig straight down as it could collapse?
Do I dig out foundation at 45 degrees slope away from house foundation to bottom of trench to avoid collapse of old foundation? - but then new concrete footing in this section will be not as deep as 45 degree wedge of mud underneath?
I cant see a way to get all the earth out without risk of collapse?
cheers