Things You'll Need
Demo saw with masonry blade
Steel door frame
Drill with masonry bit
Because of their strength and durability, steel door frames are often used in masonry walls in place of traditional wooden frames. Metal frames are typically installed before the brick or block is erected. In many retrofit applications, however, it is necessary to remove and replace existing frames in walls that are already in place. To replace a steel frame in a masonry wall, special anchors are used to fasten the frame to the surrounding brick or block.
Remove the Existing Frame
Cut away any existing caulk between the frame and the masonry wall. Use a sharp utility knife for this task, and be sure to remove caulk from both sides of the opening.
Remove trim or brick molding using a pry bar or hammer. Pry the trim away carefully and set it aside for reuse.
Start at the bottom of the frame and begin to pry the frame away from the wall with your pry bar. You may need to use a maul hammer along with the pry bar to loosen the frame.
Slide a 4-inch grinder between the frame and surrounding wall and use it to cut away existing anchors or fasteners. Continue prying the frame away from the wall so you can move the grinder up the height of the frame.
Cut the frame using a demo saw with a masonry blade. Once you've cut the fasteners with your grinder, you will likely need to cut the frame into sections before you can remove it from the opening. Try cutting through either end of the header where it meets the jamb. If needed, you can also cut the jambs into sections, or cut the header in half to aid in removal.
Install the New Frame
Measure the height of each anchor along the jamb. Mark these locations on the wall at either side of the opening, then use a drill with a masonry bit to pre-drill holes for the expansion bolts.
Set the frame in the opening and use wooden shims under each jamb to level the header. Drive expansion bolts through each anchor location to fasten the frame to the wall. Depending upon the type of bolts you use, they may be drilled into the wall or installed using a hammer.
Add trim or molding around the frame as desired, then caulk all joints between the frame and the wall.
Use a welded door frame, not a knock-down model. It should be the same size as your old one, and should be approximately 1 inch smaller than the opening in both height and width. Be careful with the header size. A standard metal frame has a 2-inch header, but many masonry frames have 4-inch headers to allow them to match the masonry coursings.
Request that the frame manufacturer include existing wall anchors (EWA) with the frame. This is a standard option offered by most steel frame distributors, and may also be referred to as "punch and dimple" preps. Three holes will be punched in each jamb, and the jambs will be reinforced to accommodate expansion bolts.