Install a prehung exterior door

摘要

Installing a prehung exterior door is straightforward. Assuming the wall is plumb and that the rough sill and opening are flashed, the first step is to check the rough sill for level. If it isn't level, set the door unit in place, and shim the low side until it is level. Add shims about every 6 in. for solid support. Remove the door unit without disturbing the shims, then bed the shims in window and door sealant. Before placing the door in the opening permanently, squeeze several thick beads of sealant across the top of the sill flashing to keep out wind and rain.