Preparing for a new door

Guidance on some things you can do to prepare for a new door to be fitted

The following pages will cover a few things that are important when preparing to replace a door:

You need to ascertain the swing of a hinged door to ensure it will open in the correct direction. The swing of a door can also be known as the hand of a door. The terminology concerning the swing of a door will differ between manufacturers, but it basically refers to which side the hinges are on and whether the door opens outwards or inwards. It's particularly relevant when you are buying an  external door set frame   as these will be inward or outward opening doors and come ready to fit already fixed to a sturdy frame.

It's important to get the measurements for a new door correct before you buy it. Ordering the wrong size door can be an expensive mistake. You should also determine the swing or handing of the door you want to replace, if it's a hinged door, so you can order the correct door type. There are two ways to measure for a new door slab. If the old door is the correct size and fits squarely within its frame, you can measure the old door leaf itself. If the door has warped or no longer fits properly, or if you're installing a door into an empty frame, you can get the correct measurements from the existing frame.

If you want to replace an entire door unit you'll probably want to buy a doorset or door assembly, so that both frame and door leaf will be replaced. Door sets are sometimes sold as French door sets , for more than one door leaf, or as door set frames, ready assembled single door assemblies. If this is the case you shouldn't take the measurements from the old door or frame, it's better to measure the rough opening in the walls. The doorway without any frame is usually called a rough opening or a structural opening. 

If you're adjusting a door for a new type of flooring; replacing the door leaf, frame or entire door set; or you need to repaint or trim parts of the door, you'll need to remove the old door from its frame. The type of operation the door uses will affect the way it needs to be removed. If you intend to keep and reuse any part of the door assembly you should be extra careful not to cause any damage to those parts. Bent or damaged parts of the frame, door leaf, or hardware can cause a door to fail. Doors can be heavy, awkward, and tough to work with, so you might need to get someone else to assist you, especially with external doors.

You may want to remove the door frame and architrave to replace them, or if you want to remove a doorway altogether. It is usually simple to remove them with some common DIY tools. You should first remove the door. Remember, door frames will have variations in their design – if you have any doubts about removing any components you should consult the manufacturer or a professional builder.