How to measure the structural opening

In order for us to provide you with a more accurate quotation, we will require an approximate structural opening size of the existing doorset. Please read the following step by step guide to measuring the opening.

Measure the width externally; top, middle and bottom. Doing the same again internally.

Measure the width externally; top, middle and bottom. Doing the  same again internally

Measure the height externally; either side and middle. Doing the same again internally.

Measure the height externally;     either side and middle. Doing the same again internally.

Measure and check the diagonal measurements which should be the same both sides.

Measure and check the diagonal measurements which should be the same both sides.

Frame will generally be fitted from the outside. The smallest dimension for width and height of the structural opening will be used. The diagonal measurements should be the same and will indicate if the opening is square. If they vary by more than 5mm then additional clearance should be allowed when calculating the frame size. Check the frame is not recessed behind the external brickwork, as in Figure A. Check the exisiting frame head, cill and threshold condition. Is a cill required or temporary brace. If a mobility threshold is required this should not protrude more than 15mm above the finished floor level. Is there adequate external drainage to prevent water ingress.

  • Frames will generally be fitted from the outside. The smallest dimension for width and height of the structural opening will be used. The diagonal measurements should be the same and will indicate if the opening is square. If they vary by more than 5mm then additional clearance should be allowed when calculating the frame size.
  • Check the frame is not recessed behind the external brickwork, as in Figure A.
  • Check the existing frame head, cill and threshold condition. Is a cill required or a temporary brace? If a mobility threshold is required this should not protrude more than 15mm above the Finished Floor Level. Is there adequate external drainage to prevent water ingress?

If in doubt please do not hesitate to contact us. Often a photograph of the existing opening can make understanding the concern much easier.