Assembly instructions for a standard interior door

                                             

The frame of the door, or lining for the door , will keep the door closed. It is critical to ensure that the frame is correctly assembled and installed straight, level, and plumb. The door can then be easily installed and will function properly.  

               

Doors and frames can become worn or damaged over time and must be replaced. New frames are frequently sold separately from the door slab, as a frame kit with jambs, head, and stops that must be assembled on-site.  

More information on measuring for a door frame can be found at: How to Measure for a New Doorset.

               

Not all doors are the same, and there are various types of frames, so check the specific instructions with the frame you select. Here's a basic guide to assembling and installing a standard internal door frame without a sill, which is typically made of wood. Other materials' frames may have different instructions for how to be joined together. To fit properly, the frame may need to be trimmed, so use an appropriate saw or a similar cutting tool.

                   

An Kit for internal door frames will typically include a head, two jambs, and separate stop pieces The head piece can frequently accommodate two different door sizes. The jambs are designed to fit into recessed areas in the head. These recesses are typically cut into the head at different distances on each side, so you should first determine which recesses you'll need to use by measuring the width of the door.  

                   

Place the frame on a clean, dry floor or appropriate workbench with enough room to assemble it. Insert both jambs into the appropriate recesses in the head. You may need to use a hammer to firmly tap them in. After that, use a long screw to secure each jamb in place. You have now completed the main components of the basic frame.  

                     

The head piece is usually wider than necessary. Trim either side of the head to be just less than the width of the opening. Ideally, you should have just enough space around the frame to make minor adjustments when it's in the opening.

                   

When installing the frame, it should be level, straight, and plumb, and it should be as accurate as possible. Build braces out of scrap wood to keep the frame in the proper shape while it's being fitted. These should be attached with thin nails so that they can be easily removed later.  

             

First, brace the frame's bottom. Measure the distance between the jambs at the head of the door and secure the timber to the jambs at the bottom of the frame so that they are the same distance apart all the way down. Then, using a level and a set square, check the top corner of the jamb that will hold the hinges. This corner must be square and level. Use another piece of wood to keep this corner square. If you want, you can repeat the process on the opposite top corner.

    

By measuring corner to corner on the diagonal, you can determine how square the entire frame is. Both of these measurements should be the same. If the difference in measurements is greater than 5mm, you should check and reposition the braces.  

                     

If your measurements are correct and the frame is completely level all around, you should be able to carefully push it into the rough opening. There should be enough space between the frame and the wall to make minor adjustments if necessary.

             

Check that the frame is still level and plumb with a spirit level. To properly align the frame, use wedge-shaped door packers or shims, which are thin pieces of material that go between the frame and the wall. These can be used to make up for any areas where the walls are uneven. Ideally, your door frame should be flush with the wall or protrude by about 1mm, especially if architrave or trim is being installed.

             

You can put more than one shim or packer in where they're needed, so use particularly thin pieces that you can build up if necessary. Long shims or packers are preferred because they are easier to adjust. Shims or packers should be placed approximately where you intend to insert your fixings to hold the frame in place, so that they will pass through them and into the wall. They should also be placed near the hinges. If necessary, use a hammer to drive them deeper into the gap.

             

The placement of the fixings, which are usually nails or screws, is determined by the type of wall they will be installed in - stud or brick. Get the head level first and secure it in place, then plumb and secure the jamb that will hold the hinges, and finally secure the other jamb. Use fixings that are at least 80mm (318") long and suitable for the wall material. Mark the spot where the fixings will go first. If there is a sill, the instructions should specify when it should be installed.

                       

The fixings are attached in pairs along the length of the jambs. Begin approximately 100mm (4") from the floor and space them at approximately 450mm (1734") intervals. They should be placed about 30-35mm (about 134") from the jamb's edge on either side.

               

The fastenings must be staggered to prevent bricks or blocks from splitting. They should be installed about a third of the way in from the jamb edge. The instructions should specify the proper spacing for your frame.  

             

Using a spirit level, double-check that the frame is still straight, level, and plumb within the opening. You can fix a shorter level to a longer straight tool, such as a rule or straightedge, or a long piece of straight timber, to increase its accuracy over a longer length. Once the frame is in place, the shims can be trimmed or scored with a knife and then hammered off flush with the jambs.

               

Where the frame meets the wall or has recessed fixings, it is finished with an appropriate filler or plaster. Internal door frames typically have a trim, similar to architrave, installed to conceal where the frame meets the wall. There is a variety of fashionable matching oak architraves and skirting boards available to complement your door and provide a stylish finish

For more information, see How to Install a Door Architrave.