How to fit door architrave

The architrave of a door is the trim which you see around the door frame of internal doors , it will often match the skirting board in the room. It hides the gap where the frame meets the rough opening. It can also be referred to as moulding, especially if it is particularly decorative or used externally, but, it's not commonly found on external doors in the UK. For more information on door frames for internal and external doors, see: Door frames

To browse all Oak architrave and skirting, including architrave for single and double doors, click here

Architrave will usually be supplied separately to the rest of the frame, as one long piece to be cut up, or shorter, ready-cut pieces. Most architrave pieces are joined at the corners with 45-degree mitred ends to form 90-degree corners. If necessary, you'll need to measure and cut the pieces to the right size and shape. It's best to fit the door leaf before you fit the architrave. 

Check if the architrave has been fully finished or if it needs to be treated as this needs to be done before it's fitted. Usually, timber architrave needs to be treated with at least three coatings of a high-performance wood stain on all edges and faces. If you choose to varnish the architrave, this should be applied as an additional coat to all edges and faces.

How to measure and fit architrave

Architrave needs to be measured and cut accurately or it can ruin the look of your door. But, when it is accurate and fitted correctly it can be a very attractive feature which enhances the door's appearance. Check the material your architrave is made from and make sure the saw you use has an appropriate blade. If the architrave is for an external door, usually referred to as brick moulding, make sure all edges are appropriately sealed, including the ones you cut.

Step 1 - Mark out reveal 

You want to leave about 5-10 mm of frame showing once the architrave is attached, this is called the reveal. It's best to mark this on the frame so you'll know where to place the architrave when it's been cut. Choose the exact size you want the reveal to be and measure and mark this distance from the edge of the frame, and mark this same distance in a few places around the frame. 

If you have a combination square, or similar tool, you can set this to your required distance and use it as a guide to mark at various places around the frame. This will be more likely to provide a consistent size of reveal all around the frame. It's particularly important to mark the reveal on the two corners. If the door frame is not completely level, straight, and plumb, you can compensate by altering the reveal as necessary and ensuring the architrave is level.

Step 2 - Mark where to cut the mitres on the side pieces

You can measure where you'll need to cut the mitres, but it's usually more accurate to mark it out directly than transferring measurements. Position the first side pieces of architrave against the marks for the reveal, leaving enough space at the bottom for the flooring. Mark where the inside corner of the architrave needs to be on both side pieces.    

Step 3 - Cut mitres

Cut each piece at a 45-degree angle from where you have marked the inside corner. Use a mitre box and hand saw, or mitre saw, to ensure the angles you cut are accurate.

Step 4 - Fit side pieces of architrave

Once the side pieces have been cut to the right size they can be fixed in place with nails spaced evenly down the architrave. Make sure the inside edge of the architrave lines up with the reveal marks you have made. Some people choose to also use wood glue to attach the pieces, but this will make them more difficult to remove in the future.  

Step 5 - Cut top piece of architrave

Cut one end of the head piece of the architrave to a 45-degree angle. Hold the head upside down between the points on the outer edges of the side pieces and mark where the outside corner of the second mitre will start. Cut a 45-degree angle at the other side of the head piece.  

Step 6 - Fit head piece of architrave 

Fix the head piece between the side pieces with finishing nails, lining it up with the reveal marks. Use a nail at either side and one in the middle. Use a nail either side of the head piece, driven in from above or the side, to secure the corners.

Step 7 - Finish

Use a nail punch to carefully knock the heads of all the nails used below the surface of the architrave. Fill where the nails have been sunk in and in any gaps between the mitres with decorator's caulk. When this has dried, the architrave can be sanded if necessary then primed and painted. The nails should be hidden below the paint.