Composite Door Measuring

When replacing a front door with a composite door, it’s important to get the measurements right, as each composite door is manufactured to the specific measurements of the opening.

And when it comes to measuring for the door, it’s not quite as straightforward as you might think. 

There are many variables to consider, each of which could affect the door’s functionality when installed. 

Things to bear in mind

  • When measuring, always measure the opening from brick to brick
  • Always measure the opening as viewed from the outside
  • Record measurements in metric, using mm 
  • Final measurements should include the sill and any additional items such as frame extenders

How to measure for a composite door

Because the size of your opening can fluctuate slightly along the height and width, it’s important that you get three measurements of each.

When measuring the width, get one measurement from the top, one from the middle and one from the bottom of the aperture. Then make a note of the smallest of the three.

Repeat this process for the height of the door, with a measurement of the right-hand side, left-hand side and middle of the opening. 

Reducing measurement to account for expansion 

You will need to reduce your measurements slightly to account for expansion.

Depending on whether you have a white or non-white uPVC frame, this adjustment will differ slightly. Reduce your measurements as follows: 

For White uPVC frames: 

  • Up to 3m – Reduce by 10mm
  • 3m-4.5m – Reduce by 15mm
  • Over 4.5m – Reduce by 20mm

For non-white uPVC frames: 

  • Up to 3m – Reduce by 15mm 
  • 3m4.5m – Reduce by 22mm
  • Over 4.5m – Reduce by 28mm

Please note that the reduction should be made from the total width, and not taken from each side of the opening.

Once you have your measurements, you’re ready to order your composite door.

Looking for a trusted supplier of composite doors in Worthing? At MLI Building Products, we supply composite doors across Worthing and surrounding areas. Simply give us a call or drop us a message to see how we can help.