: I am installing a toilet in a basement and the 4 drain does not come up through the cement floor straight, therefore, when I put the mounting flange on the pipe it does not sit level (3/4 higher on one side than the other). What can I do short of breaking the cement floor to straighten the pipe?the best thing would be to straighten pipe! you might also cut off pipe flush with floor and use a 4 x 3 flange. place a good bead of rubber caulk under flange in order to seal it to 4 pipe and lag bolt it to floor. then regular closet bolts could be used to seat toilet. i would check flange first to see if it has enough play to end up level.