i am wanting to do my own foundation. I have done concrete abutment walls for a bridge so have a good idea of concrete etc. Soil is hard solid clay. Dig down a foot and you are in it. Looking at 3200 sq.ft. beam wall. Going to drop a footer 12 to 18 inches wide down into the hard clay below frost of line, which in texas isnt very far down.
will come back pouring the grade beam (actually above grade) ...then putting in the piers in middle. 1 foundatiin company already told me 3 to4 feet would be sufficjent and 2 other homes very close by are on 3 ft. Piers and have been therr for 30 yeard with zero problems.
my question...i have a thought of running some deep piers...up to 10 ft. Down below grade beam 2 ft. Off each corner. I know this wouldnt hurt but do you think it would help?
also....the design plan calls for piers 10 ft. Apart...2x8 joists but doesnt specify girder. I was tuinking of using 2x12 doubled as girders....possibly overkill?