Are you thinking of getting a new door for your home? Ordering the wrong size is a surprisingly common mistake, but one that can prove extremely expensive.
Even if you are allowed to return the door to the seller, you will probably still have to pay transport costs. On top of that, you’ll have all the bother of finding a replacement door and paying again for delivery.
Following these simple steps will help you work out which size you need.
Accuracy is key. Unless you are buying a whole new door set (door leaf and frame), you need to ensure that your existing door frame is completely straight and level. The best way to check this is by measuring diagonally from corner to corner, in both directions. If the measurements vary from each other by more than 5mm, you might have to adjust the frame – a job best left to a carpenter – or buy a new one.
Inspect the condition of the frame as well. It needs to be strong, as a door can weigh up to 50 kg. If there is much damage you may be better off buying a complete door assembly (frame and door).
When calculating which size of door is required, you need to find out the following:
· Door leaf size
· Door hardware positions
· Door frame size
How to measure the door leaf
Measure the height, width and depth of your old door, taking each measurement several times at different points. If there is much variation, use the largest figures. Most doors can be slightly trimmed to fit, but if a door is too small there is nothing you can add!
How to measure for hardware
Doors normally come without any hardware such as handles, locks, latches and hinges. If the existing fittings are in good condition you may be able to re-use them. Otherwise, you’ll need to order hardware separately and fit it to your new door before installation.
Remember to measure the exact position of the old hinges, handle and closing mechanism, so you can fit replacements to line up precisely with the frame.
To take an accurate measurement for the hinges, run a tape measure from the top of the existing door to the top of each hinge (there will probably be at least three). Make sure you lay the tape flat against the face of the door, and keep it straight.
You also need to measure the size of the hinges, and the hinge reveal (the distance between the edge of the hinge and the edge of the door).
Next, measure the position of the lock set – the latching mechanism. This is important to get right, as the door may not close properly if the latch doesn’t align precisely with the corresponding cavity in the frame. Measure to the centre of the lock set from both the side and top of the door.
How to measure the door frame
When it comes to the door frame, make sure it is only the actual frame that you are measuring. There will generally be architrave or other trim attached to the walls, as well as door stops.
Work out the width and height of the frame, taking several measurements from different positions. If the figures vary, use the smallest sizes in your calculations. To ensure the door won’t scrape along the floor, always start from the highest point of the carpet – and if you are planning to lay new carpet or any other flooring, remember to allow for it.
To find out the depth, or thickness, of the frame, measure only from the front edge of the door post to the front edge of the door stop. Don’t include any trim fixed to the walls.
Now that you’ve got all the measurements, you will probably be able to find a standard door that is a close enough match. Most wooden doors can be trimmed to fit, but this is not the case for all models, so do check before you buy.
If your frame turns out to be a non-standard size, you may want to consider a custom-made door. This option tends to cost more, but will ensure a perfect fit.