Things You'll Need
Anchors, screws or bolts
Steel doors and frames are often used in commercial applications, as well as in some exterior residential openings. They offer additional strength and support compared to wooden units and are also longer-lasting. A steel door and frame can be installed into any type of wall including drywall or masonry partitions. Unlike residential pre-hung units, steel doors and frames are typically installed separately from one another. To improve your chances for a successful installation, it's important to size the door and frame correctly and use the right tools and equipment for your particular project.
Installing Steel Frames in Drywall
Choose the correct frame. Use knock down steel frames for installation in drywall partitions. These frames come in three separate sections so they can be installed after the drywall is finished. The jamb size on your frame should be 1 inch larger than the thickness of the wall around the opening. For instance, steel frames in 4-7/8-inch walls should have a jamb depth of 5-7/8 inches.
Angle one jamb of the frame so that you can fit it into the opening. Starting at the bottom, press the frame firmly against the wall so that it slips around the edge of the opening. You may need to use a rubber mallet to tap the jamb in place.
Connect the header. Fasten the tabs or clips at the top of the installed jamb to the corresponding clips on the header. Wrap the header around the top of the opening.
Install the remaining jamb by fastening it to the clips at the end of the header. Work your way down the wall, pressing the jamb into place so it wraps the drywall partition.
Tighten the compression anchors on the frame using an Allen wrench. These anchors should firmly hold the frame to the drywall but should not be over-tightened. When these anchors are too tight, they can warp the frame or damage the drywall.
Installing Steel Frames in Masonry
Select the right frame for the job. In a masonry wall, steel frames should have a jamb depth equal to the wall thickness. This allows the frame to butt up against the masonry rather than wrapping around the walls. A steel frame installed in a 6-inch block wall will require a 5-3/4 inch jamb depth. This is because a 6-inch block wall will actually measure 5-3/4 inches, which is standard practice with masonry materials.
Install the frame before the masonry work begins. Layout the floor and determine the location of the door. Set the frame at this location and fasten it to the floor using concrete anchors or screws, depending on what the subfloor is made of.
Brace the frame using 2-by-4s or a door jack system designed to support a steel frame. This bracing is used to hold the frame in place as masonry is installed on either side. Add spreader bars to support the jambs until the door can be installed.
Use wire anchors to hold the frame in place. These anchors are welded into the steel frame at each hinge location. As masonry is erected, the wire anchors are embedded into the mortar between the rows of block. Once masonry work is complete, the spreader bars and bracing can be removed from the frame.
Installing the Steel Door
Size your steel door correctly. Your door should be 1/8 inch smaller than the frame in width, and 3/8 to 3/4 of an inch shorter than the frame depending on the height of the threshold or flooring.
Consider hardware preps. Steel doors and frames are pre-cut at the factory to prepare them for hinges and locks. The hinge and lock preps should match the locations on the frame, but will be 1/8 inch higher on the door than on the frame. For example, if the top of the uppermost hinge on your frame is 6 inches from the top of the frame, this same hinge will be 5-7/8 inches from the top of the door. This allows a 1/8 inch clearance at the top of the door so it will not bind with the frame.
Install the door. Screw the hinges to the door, then have a partner hold the door in place while your fasten it to the frame. Add shims behind the hinges as needed to level it out and help the door swing properly in the opening.
Install your chosen lockset according to the manufacturer's installation instructions. Fasten the strike to the frame using the screws included with the lock. Test the door's operation to ensure all components are functioning as intended.