When doing a renovation or adding an extension, it often becomes necessary to replace a door and jamb or install a new one from scratch.
Jamb moulding components are available and DIY installation is a lot easier if you apply a few clever tricks to speed up the job.
If the walls are out of plumb or the floors aren’t level, you will need to correct these problems first or the door won’t open and shut properly.
Once the jamb is secured in position, you may need to trim the door to size before cutting housings for the hinges and hanging the door.
Use a drill with a holesaw and spade bit to bore the holes for the lockset and latch, then finish by securing the architraves.
Instead of standing the doorjamb in position while you insert wedges behind the hinge side, secure shims in the door opening first.
Measure the width of the doorway opening to calculate the thickness of the shims you will need.
Usually the opening allows for a gap of about 10mm on each side of the doorjamb.
If the opening is extra wide, you can use smaller wedges by temporarily securing offcuts of 12mm plywood at each of the hinge locations, then adding wedges or shims to plumb the jamb.
Position the shims at the top and base hinge locations using a long spirit level, or a straightedge with a shorter level, then add the centre shims if a third hinge is needed.