Door casing width for 100mm studded wall

[Whimsical]

Hello,

I'm replacing some old internal nonstandard sized doors which will also require me to replace the door casing. The timber of the studded wall is 75mm with 12mm plasterboard on either side (total approx 100mm).

Not sure the width of casing to get though ive seen 100mm casing, 106mm, 108mm. (will have to alter the header as cant seem to find any for 686 doors) Not sure of the ideal width in this situation. Would I expect the plaster finish to be 3mm iether side... seems a bit thick.

Sorry if this is a really dumb question!

 

[foxhole]

2-3mm plaster is usual so the 106mm would be OK.Door linings would be preferable.

 

[Whimsical]

Excellent. Many thanks

 

[TheGayOwl]

106mm door linings are often referred to as four and a half inch linings at timber yards, so ask for that.

They would have started out around 115mm but trimmed (dressed) to approx 106mm.

 

[Whimsical]

Ah, I did'nt know that thanks. 115mm would be easier for me to get hold of at trade cost