How deep a door frame do I need to buy for a 100mm stud wall

[EBrant]

Hello

I am building a stud wall out of
50x100mm x 2.4m CLS (fin 38 x 89mm)

I will be fixing 12.5mm plasterboard to both sides of the wall thereby adding another 25mm, I will then be applying a skin coat of plaster to the plasterboard (again for both the inside of the room and outside of the room) adding say about 5 to 6mm I guess.

Can some one please tell me what depth of door frame should I order? taking into account the architrave I need to fix on (I assume this is fixed on at the end) to finish off the door framing).

Also about, wood I ordered is described as 50x100mm bit then it says 38x89mm (the word is described as stud wood) therefore is it 100mm deep or 89mm deep (as this is going to form the wall depth where the door frame need to fix (taking into account plasterboard and plaster as above).

Thanks All :)

E Brant

[ayjay]

You need a door liner (frame) with a finished size of 120mm.

The 100 X 50 is a nominal size - 38 X 89 is the finished size.

[EBrant]

Thanks very much ayjay :)

E Brant

[steviejoiner74]

I never use cls as its sizes are not suited to stock door frame sizes.
For example if you use 70x45 c16 timber, for your stud work 12.5mm plasterboard both sides you use 95x33 for your door frame. Same with 95x45 c16 timber and 12.5mm both sides,you use 120 x 33 for your door frame. These are all standard stock sizes.

[EBrant]

Hello Stevie

Thanks very much for the information, that is very usfull. The only reason I ordered CLS was that is what showed up on TP WEB Site when looking for stud timber.

Do you know what C and CLS actually stand for? (I am an electrician by trade not a chippy), I will have to check if I can get C16 timber from Travis Perkins if not where is a good place to buy this please?

Thanks
E Brant

[philprime]

CLS stands for 'Canadian Lumber Standard'. CLS was originally manfactured in Canada for use in the building of timber framed houses, hence it's name. Over the past few years CLS has become increasingly popular in the UK for use as framing for stud walls and internal partitions. The UK version is usually manufactured from European or Scandanavian softwoods.

Timber must be graded if it's to be used in internal structural applications as stipulated by building regulations. Timber is graded to either C16 or C24. Here all the structural properties of the timber are quantified. Eg Species, Knot Size and Type, Slope of Grain, Tightness of grain, Compression Wood, Rot etc. C24 grade can only be achieved by imported timber. Homegrown timber from UK sawmills will make C16 only and so will have reduced span capability.

Basically it's down to the grading of the strength of the timber and TP do stock c16 timber HTH

[EBrant]

Hello again

Can someone explain one last point please

if I have an 89 finish then add 25 (plasterboard e.g. 12.5 x 2 = 25) that comes out to 114, so should I not fit a 115 door frame, then add the architrave (which I assume adds about 7mm or so per side), than skim the plaster upto the side of the rchitrave
or should I skim the plaster board then add the architrave?

Thanks All
E Brant

[ayjay]

Hello again

Can someone explain one last point please

if I have an 89 finish then add 25 (plasterboard e.g. 12.5 x 2 = 25) that comes out to 114, so should I not fit a 115 door frame, then add the architrave (which I assume adds about 7mm or so per side), than skim the plaster upto the side of the rchitrave
or should I skim the plaster board then add the architrave?

Thanks All
E Brant

I always allow 3mm for a skim coat to add to your measurements - that gives you 120mm.

The purpose of the architrave is to cover the joint between the door liner and the plaster: this joint will always crack and show up if left uncovered.

The plasterers will work to the door liner with the skim coat and the architrave is fitted after plastering and after the doors are hung; if the plaster is proud of the door liner the architrave won't sit flat and the mitres will need fiddling with to meet correctly.

[EBrant]

Thanks very much again ayjay (and everyone else) that is very helpfull

So what I have I actually gone for is the original CLS wood (finishing at 89) plus a 32x125 door lining as below

http://www.travisperkins.co.uk/p/32x125 ... 31/2893372

As I am told by TP that the 125mm actually finishes at 119mm theerefore my logic says CLS finishing at 89 + 25 (2 x 12.5 plasterboard) + 6mm skim (3mm each side of wall) = 120mm therefore door lining finishing at 119mm should be as close as dame it.

I hope I am right now, if not please say

Thanks again for taking to time and trouble to help me out with my questions

E Brant