Doorcase sizing when fitting

[marsaday]

What height and width do you leave for the doors to be fitted when putting in a casing? I need to allow for carpet - maybe 10mm as no underlay.

Is it normal to leave 20mm in height. Would 5mm width allowance be too mean ?

 

[noseall]

Most door casings are sized so that they have aboot 16mm tolerance over and above a standard height (6' - 6") door.

 

[marsaday]

Ok, thanks. What about width ? Basically i have some old casings in place, but they need adapting. I can simply reduce the heights by adding a new head, but the width is at 765mm and a new door is 761mm wide i think. Would 2mm tolerance each side be ok ?

 

[gregers]

that should be fine,dont forget the hinges will throw the door a tad,depending on type fitted.

 

[joinerjoe]

There is a difference between internal and external doors see this link for internals: http://www.thediyworld.co.uk/Fitting_internal_doors1.html