What size timbers for stud walls?

[Nozzle]

I've cut down some flat roof joists as that structure is redundant. The timbers are nice a dry and have been up there for 30+ years; I'd like to re-use the timber for some stud walling.
Either as a stud-wall in it's own right (with rockwool insulation) and/or as the inner wall as a part of cavity walling.

If you were to go to a timber merchant right now, what size timber would you buy, 150x50? I intend to re-size these timbers to make it available for immediate use by the builders.

The point being it saves me having to store it, and it's better to re-use than buy new.

Nozzle

 

[foxhole]

You can make a stud wall frame from of either 75mm x 50mm or 100mm x 50mm of sawn timber.Most important is it needs to be true , no twists, warping etc.Do you have use of a decent table saw?

 

[freddiemercurystwin]

I lived in a house which had 25x50 studs, the studs were positioned lengthways parallel with the wall so overall the walls were 50mm thick. Surprisingly rigid actually.

 

[Nozzle]

25x50, small!!!

I don't have access to a table saw, I was just going to use the hand-held circular saw with the rip fence. Currently the timbers are true, and I'll make sure the blade is properly 90 degrees before I start cutting.

Nozzle

 

[freddiemercurystwin]

Yep, first house I ever bought, brand new fella, first found out the walls were so small because the first hole I ever drilled in the place went straight through a partition! I was gob-smacked, as it was a new development there were other houses still being built so I let myself through the heras fencing one weekend for a recce to see how they were being built and sure enough 25x50's parallel to the walls. Loved that house, only thing I ever had to do was replace the bathroom extractor fan in the twelve years I owned it.

 

[Deleted member 174758]

I don't have access to a table saw, I was just going to use the hand-held circular saw with the rip fence. Currently the timbers are true, and I'll make sure the blade is properly 90 degrees before I start cutting.

Cheap-jack jobs use 3 x 2s (often 70 x 44mm) whilst the better jobs use 4 x 2s (approx. 90 x 44 finished). It is very important that the timbers are sized alike with little variation otherwise you'll have no end of problems when it comes to boarding out

 

[Nozzle]

Do door carcasses come in different "depths" too?

Noz

 

[JohnD]

you mean readymade door linings? Yes.

I have only used 106mm and 132mm that I can remember. In older houses I have had much wider ones that tend to crack.

 

[Deleted member 174758]

Which is why deep openings tend to have linings in older buildings or heavier rebated frames in newer work, I suppose

 

[Nozzle]

So 106mm casings for 70mm timber and 132mm casings for 90mm timber? Does the chippy make his own casing if the timber for the stud wall is 100x50mm?

Nozzle

 

[Deleted member 174758]

Bought-in casings only get you so far. For 100mm timber, assuming the boards are 12.5mm per side and that a 3mm skim will be applied each side as well gives you a casing width of 131/132mm. 131 wide x 2010 high is a standard casing for a 6ft 6in high door. Most of the commercially available softwood casing kits I've seen (with planted-on stop laths) are machined with two housings on each side of the head - one pair for 2ft 6in (762mm) doors, the other for 2ft 3in (686mm) doors (see here). If a carpenter needs to accommodate another, non-standard, width of door he'd probably use a router or a compound mitre saw to cut a new housing. If the casing is going onto a wall built on, say, 80mm timbers with 6mm boards (giving 99mm frame thickness) then the casing is ripped-down to width before assembly. If the casing needs to accommodate some feakishly deep opening, then the front edges are rebated and rebated planking (MDF, pine, etc) can be used to make-up a lining tio which an architrave can be fixed, thus:

Above: Assembled casing kit
Below: Modify to take lining (rebate)

The lining is made from available materials and the edge rebated to match the rebated edge of the made-up casing:

View attachment 94720

The door casing is fixed in place, then the lining is added afterwards. A rebated joint is to be preferred as a plain butted joint can and will open up over time. The rebated joint tends to hide this and can be neatly caulked if it ever does open in te future. For oddball sizes or for hardwoods (where kits are generally not available) I make-up my own linings using pre-planed board stock and I often rout out the housings and rebates on-site. Whilst the linings can be the same thickness as the casings, it is not always the case and devices sush as edge beads on the lining are used to disguise the joint. The rebate can also appear on the inside of the lining as well as the outside depending on the desired look

 

[Nozzle]

Thanks so much for taking the time to put that post together; you've put in some much appreciated effort. I can see from your notes about modifiying a casing that it seems to be quickers and easier to start with the raw materials and make your own up rather than faff about machining a smaller one to fit. A sample of the casings in the existing part of the house suggests 130mm, though that is a block wall rather than timber. I'll go for 90mm cuts - I assume the accuracy I can get with a handheld circular saw and rip fence is close enough?

Nozzle

 

[Deleted member 174758]

Yes. Just make sure that the joints in the corners are flat, even with bought-in kits can be a little bit out. If needs be plane in with a jack plane or block plane. If you rip down a kit the sawn edges should also be planed smooth (only takes a few strokes with a sharp plane) because 5 to 10 mm of the edge will be visible as the architrave reveal