Measuring a front door

[monkeymagic]

Hi,
I am considering buying a front and back door off an online company but I have to measure the doors myself.

I have been googling and see that I have to measure from brickwork to brickwork in three different places horizontally and vertically which I have done.

But I am getting confused as some websites say then to deduct 10mm off the smallest measurement and some say to just take the smallest measurement.
Could anyone help please?

Another problem is that the we have a top light (we are getting another front door with a new top light) and the brickwork around the very top of this is arched - so if I measure in three places vertically from the floor to the top light, I am measuring the 2 smallest parts of the arch and the 1 part in the centre where the arch is at its highest and am unsure what to specify. What should I do?

How accurate must you be when measuring doors? are there room for errors?
as the doors cannot be returned.

 

[chezzer0361]

I had the same problem, and at 600 to 700.00 for a new door, there is no room for error, either explain to the company you are buying off what you have measured, draw them a diagram and let them make it . or get someone round to do a quote, get the paperwork off them and then use their measurements.

or if you are lucky like me, when you parents are having new windows fitted talk nicely to the lads fitting them and see if they will do it as a back hander, or get the wife to ask, somtimes it pays to be a chick

 

[MANDATE]

When fitting new frames it is normal to deduct 10mm, so the frame is packed out 5mm all round (or more if there is any out of squarness).
Some manufacturers want the smallest size and they will make the deduction. In my case I made the deduction and gave actual size of frame required.
You mention brickwork which suggests you mean frames but then you mention measuring the doors.
I'm assuming you mean frames and I would measure and test for any out of squareness first. I had considerable out of squareness so decided the 5mm gap would only be 3mm. As it happened the frame did foul on one side for about 300mm but corrected this using electric plane.
Regarding the arch, most arches I've seen are plain 'filling in' above a rectangular frame, in which case the three measurments will only be two.
If it was to be part of the frame a template to get the correct curve would be required.

 

[breezer]

why not email the company and ask what they want?