How to Make Door Jamb Extension

To make a door or window frame larger and ensure that it fits into a wall, a piece of wood or other material is connected to the inside of the frame which is called a door jamb extension.

When a window jamb or door jamb can not be installed securely because it is not wide enough to fit the proportions of the wall, but at that time extension jambs are widely utilized in building construction. By adding a piece of wood, a board, or another material, the jamb can be lengthened and made to fit tightly.

  • What is the meaning of door jamb extension?

A door’s doorframe is called a door jamb. The majority of door jambs are constructed of wood, and they can be found above the door as well as on its sides. The side jambs are referred to as being on either side of the head jamb, which is the top jamb.

  • Where the door jamb is attached to the door?

Along with the jambs, door casings are fastened with nails. Most of the time, builders will build door jambs that are the same thickness as the wall. However, proper craftsmanship might occasionally leave a small empty area in front of the entrance.

  • How door jamb matches the proper wall thickness?

Another factor is that the wall’s thickness is occasionally inconsistent and that it occasionally has cladding layers. This gives the door a messy, ugly appearance. The expanded door jamb’s function is to match the wall’s thickness.

  • The installation process of the door jamb extension

A strong door jamb is necessary for your door to open and close properly. We’ll demonstrate how to level and install a door jamb by yourself. You will also learn how to dimension the piece of wood and where to place the door stop.

  1. Properly measure the door jamb length

The length of the door jamb extension is the first thing you need to decide. Measure the length from the drywall to the edge of the door using a measuring tape. Find out how long the horizontal and side jambs are. With a pencil, trace the door jamb’s contour.

  1. Extended door jamb making

A longer-door jamb can be obtained in a few different ways. You can either contact a carpenter for advice on the topic or inquire about suggestions from a home improvement store. Taken from aged wooden planks, wood fragments are an additional choice. Three door jambs are required to assemble the horizontal jamb, the two side jambs, and the vertical jamb.

Extended door jamb making

The jambs ought to be between 3/4 and 1 inch thick. As close as you can, put up the outline’s part. Make sure it isn’t too thin to be a piece of paper and not so thick that it blocks the entry. The task should be completed on the ground.

  1. Install the door jamb properly

Apply adhesive to the door jambs, adhere them in place, and allow the adhesive to settle. The door’s hinges can occasionally be an obstacle. Cut out the necessary shape from the door jambs using a measuring tape to determine the hinges’ length.

Install the door jamb properly

Make sure the jambs fit comfortably. Next, fasten the enlarged door jamb to the frame with nails. It is preferable to use as few nails as possible to prevent the door from appearing to be covered in them. Make sure the nails are at least 1 inch in when you hammer them in.

  1. Maintain the proper margin between the door and the jamb

Margin refers to the areas that exist between the door and the door frame. If you’re having issues with your hinge jamb, they are frequently essential. These gaps can be divided into four different categories: the hinge margin, strike margin, top margin, and bottom margin.

  1. Assemble the door jamb after cutting it to size

The top of the door jamb should be trimmed to the width of your doorframe. Next, take measurements and trim the two sides. Now, fasten the top piece to the sides using your nail gun. Hold the nail gun square to the wood for optimal results. Make sure the grooves on the side of your timber face outward if it has any.

  1. Properly level the left part of the door jamb

To check if the left side is level, place the jamb within the doorway. If not, you must use packers to level the door jamb. The left hand’s base is in decent shape in this instance, but the top requires packing. Therefore, we insert one packer between the wall and the top of the jamb.

  1. Install the stopper onto the door jamb

Your door’s diameter should be measured. Then, when the door is closed, mark the location of the door on the top plate. To locate your door stopper, use this mark. The door stopper for the top plate should be cut to size, nailed in place, and measured. Then draw the stops’ lines on the sides of the jamb, measure and cut them to size, and secure them in place with nails.

  • Advantage of door jamb extension
  1. High longevity

Your doors and windows can be made more durable with the aid of a jamb extension. It offers them defence against damage caused by termites, water damage, severe weather, and other sorts of harm. The door and window jambs benefit structurally from the jamb extension as well. Jamb extension contributes to increased longevity and reduces the need for maintenance or replacement by providing improved protection.

    2. Saves your extra cost

Jamb extension aids homes in achieving significant financial savings by providing protection and removing the need for maintenance. It aids in saving a variety of costs necessary for the efficient maintenance of door jambs.


To get the protective covering for your door and window jambs, you must first gain some knowledge about what jamb extension is and its advantages. You should think about placing jamb extensions on your property because they have so many advantages. Jamb extension makes it simple and straightforward to provide hassle-free upkeep while increasing the value of your home.

YellowCarpets always tries to provide you with the ideal solution to your interior design issues. We compile the data necessary to provide you with the ideal response to your inquiries. You also can watch our youtube channel where we upload some latest DIY home project videos which might be a part of your home improvement project.

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