I built a 23-brick-row high 2 x 1.5 brick free-standing gate post bricking in the centre cavity all the way up. I let 4 rows at a time go off for 24 hours before building the next 4. Three hours after I finished it a drunken gang of yobs coming out of the pub at 11 at night pushed it over. My concrete foundation and the bottom 4 rows were fine - still there, level and un-budged. The yobs managed to snap the pier off at the join between its 4th and 5th rows. I now want to drill two holes down right through the centre bricks of the bottom 4 rows and through the concrete foundations below using a 1m-long SDS bit, and insert two 2.5m-long 16mm rebars through them and through the concrete foundation and well down into the ground below before rebuilding, this time concreting the centre cavity instead of bricking it, once the mortar has gone off of course.
Two questions: will holes drilled using a 16mm SDS bit take a 16mm rebar or will they be too tight? Should I use an 18mm bit or would that be too loose?
Second question: I read somewhere that I should waterproof inside the centre brick cavity before pouring in concrete or it will stain the brickwork. Is that right, and if so will a dilute PVA mixture do the job?
Two questions: will holes drilled using a 16mm SDS bit take a 16mm rebar or will they be too tight? Should I use an 18mm bit or would that be too loose?
Second question: I read somewhere that I should waterproof inside the centre brick cavity before pouring in concrete or it will stain the brickwork. Is that right, and if so will a dilute PVA mixture do the job?
