The new frame of the old door – how to fit them

When reworking a found wood door, keep in mind the proper tools and techniques to get the perfect fit. Cuts are best made with a circular saw, which is equipped with a sharp blade, ensuring precision and safety during work. It is also important to use a sample guide, which will allow you to accurately guide the door when cutting.

In the case of a door modification, it is also worth adapting the fittings and latches to the existing elements on other doors in the room. Thanks to this, we will maintain a uniform style and consistency in the interior design. It is also important to pay attention to detail and accuracy during rework to ensure a perfect fit and aesthetic appearance of the door.

Big doors, small openings

The easiest to repair are those doors that just need to be cut to the size of the opening. Plan your cuts to keep the proportions of the door. For example, if the door is too high, trim a bit from the narrower top jamb and a little more from the wider bottom jamb. If the door is slightly too wide, remove the hinges and only trim the hinge side. But if you need to trim both sides, you will have to move the deadbolt fittings. Be sure to leave a 1/8 inch gap on the top and sides of the door and a gap of about 6mm inch on the bottom.

Small doors, big openings

If the door is too short or too narrow for its opening, add one or two filler strips. Wooden doors with a transparent finish leave no room for error, both in execution and selection of wood. If it’s worth it, it’s worth using the services of a carpenter who has the approach of a furniture restorer.

Short door


Reveal fresh wood by sanding down the top layer. It will ensure good sticking of the glue. To make sure the cut is straight, pin a rectangle to the door and use it as a guide for the circular saw. Place the sash in the opening and level it to the height at which you want to place the handle. Measure the gap between the door frame and the door on the right and left, top and bottom.

Prepare the filling. Use material 6 mm thicker than the door. Cut it to the width of the largest gap from step 2 and 6 mm longer than the width of the door. Drill pilot holes through the edge of the filler for the screws that will hold the filler in place. For restorations thicker than 12 mm, drill each pilot hole so that the screw heads are at least 6 mm deep. Apply glue. Place the door on the trestle and glue the filler strip to the edge of the frame with polyurethane glue or wood glue. Make sure that the infill surfaces are positioned 3 mm above the adjoining surfaces of the door. Then drive the mounting screws through the pilot holes and into the door.

Smooth the surface. After the glue has cured, use the sanding belt to smooth the filler strip so that it is flush with the surface of the door. Sand the wood before painting, either by hand or with an orbital sander. After painting, the connection between the door and the filling will be invisible. For a filler strip less than 12 mm thick, remove the screws. The point where the frame and the side of the door meet is visible on most wooden doors. To mask the repair, extend the joint line on the filler strip by cutting it with a utility knife. Use the square as a knife guide.

Narrow door

Proceed as in the case of short doors, except that the infills should be glued to the posts. (Note: If you are adding a filler strip to the zipper side, you will need to move the zipper.) After the glue has hardened, sand them so that they are flush with the surface of the door.

Tip: Before cutting the door, remove any fasteners and guards in the path of the blade.



Fitting old doors to new frames can be a task that requires precision and skill. However, with the right tools and techniques, successful alterations can be made to make the door fit any opening in your home. Remember that in the case of solid wood doors with historical value or an artistic finish, it is worth consulting a professional who has experience in furniture restoration. In this way, manufacturing errors can be avoided and the authentic character of the door is preserved.

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