Many people assume that making a door jamb is hard, but it’s actually a project almost anyone can handle. Typically, you only need a few wood boards and some basic tools to get started, meaning you don’t have to hire a professional to get high-quality results.
This approach can be especially cost effective as it allows you to buy slab doors instead of the pre-hung units most people choose. Just follow the steps below to get your new, custom door jamb made.
Shopping For The Wood
Your first step is to measure the door that will be used once the door jamb is installed. Use a tape measure and record the height and the width of the door. Once you have the measurements, add 1 ½ inches to the height and 3/6-inch to the width. With your measurements in hand, you can purchase the wood you will need. In most cases, ¾-inch hemlock is an ideal choice for this project. You will need two pieces that meet or exceed the height requirement and one piece that meets or exceeds the width measurement.
Cut the Wood
After you purchase the wood, you can but the pieces down to size. In some cases, you can have each side cut to size at the home improvement store at the time of purchase. If that service isn’t available, you can do it yourself.
Take your tape measure and mark the appropriate length measurement on the board. Use a straight edge and pencil to make the cut line. Then, use a miter saw to make the cut. Repeat the process to get the other two pieces cut to length. You should end up with two sections for the height measurement and one for the width.
Construct the Jamb
To put the jamb together, you need to place the two long pieces of wood parallel to one another. Then, place the shorter piece flush between those two sections at the side that will become the top.
Once the pieces are placed, use a drill with a 3/16-inch bit and drill two pilot holes through the long piece into the short piece, penetrating about ¼ inch into the short section and staying about 3/8 inches away from the edges. Repeat the process on the other side.
Then, use 2-inch screws to secure the pieces together, using the pilot holes as a guide.
To improve stability, you can use a section of scrap wood, measuring the same length as the original width piece, and place it on the other end of the door jamb. Secure it to the bottom using 1 ¼-inch screws, allowing it to act as a brace as you add the upper screws. Once the top screws are in, remove the brace.
Mark the Jamb for Hinges
To prepare the jamb for the hinges, you will use those attached to the door as a guide. Place the door into the jamb, centering it between the frame, using blocks it necessary to ensure the front face of the door sits flush with the upper edge of the jamb.
Trace about the edge of the hinge based on the current exposure. This allows you to line up the hinges once they are removed from the door. Take the door out of the jamb and remove one hinge. Position the hinge on the jamb, using the previous mark as a guide, and trace around the entire hinge before removing it. Repeat the tracing process for every hinge.
Chisel Out Hinge Spaces
For the hinges to sit flush, you will need to chisel out the excess wood from the jamb. Take the chisel, making sure the beveled side is up, and tap it gently, but firmly with a hammer. You want to achieve a depth of 1/8 inch in the entire hinge space. Once the entire space has had material removed, test fit the hinge to make sure it lays flat and flush.
Add Door Knob Hole
After all of the hinge spaces have been carved out, you can attach the door by the hinges. Use blocks to place the door in an open position. Next, flip the hinges down into the spaces and secure using ¾-inch screws. Then, shut the door and lift the entire unit, placing it vertically against a wall. Take a tri-square and use it to mark the location of the door knob hole on the jamb. You can now open the door.
Using the striker plate as a guide, align it with the door knob hole mark on the jamb. Make sure the curved or beveled edge of the plate extends slightly over the jamb’s edge. Then, trace the edge of the plate as well as the hole in the center before setting the strike plate aside. With the tracings acting as a guide, use a hammer and chisel to remove a ½ inch of material from the center hole. Then, remove 1/16 inch of wood from the rest of the area within the strike plate outline. Use the strike plate to test the fit before screwing it onto the jamb using ½-inch screws. Finally, test the door to make sure it latches properly into the door knob hole, chiseling out extra material if necessary.
After the above steps have been completed, you’ve successfully made a door jamb for the door and can move forward with the installation. While it does require some effort, handling the project yourself can save you a significant amount of money, making it a worthwhile venture.