Structural opening sizes?

[Tony K]

Evening 

I've seen various guides on this topic, and they seem to differ regarding the critical dimensions! 

 

I'm using metal stud walls internally. How much larger than the actual door should I make the hole in the wall?! 

 

Alternatively, should I buy a standard door lining set, construct it and build the frame up to (and attached to) that? 

 

Cheers 

Edited April 8, 2023 by Tony K

[Nickfromwales]

51 minutes ago, Tony K said:

Evening 

I've seen various guides on this topic, and they seem to differ regarding the critical dimensions! 

 

I'm using metal stud walls internally. How much larger than the actual door should I make the hole in the wall?! 

 

Alternatively, should I buy a standard door lining set, construct it and build the frame up to (and attached to) that? 

 

Cheers 

Internal walls aren't "structural" per-se, so you wouldn't be factoring in deflection etc. Are you referring to all internal work here?

[Tony K]

9 minutes ago, Nickfromwales said:

Internal walls aren't "structural" per-se, so you wouldn't be factoring in deflection etc. Are you referring to all internal work here?

 

As you say, the opening isn't structural exactly, that just seems to be the term most commonly used for the hole in an internal wall where a door will one day go. 

 

I don't need to worry about deflection, the frame itself accounts for that (not that I'll have much). 

 

I want to complete the metal stud walls and also plasterboard one side of the walls (all internal), ideally just leaving openings where the bedroom doors will later go. 

 

My instinct is to take the size of a door, add 40mm to both sides and the top and create an opening of that subsequent size. 

[Nickfromwales]

1 minute ago, Tony K said:

 

As you say, the opening isn't structural exactly, that just seems to be the term most commonly used for the hole in an internal wall where a door will one day go. 

 

I don't need to worry about deflection, the frame itself accounts for that (not that I'll have much). 

 

I want to complete the metal stud walls and also plasterboard one side of the walls (all internal), ideally just leaving openings where the bedroom doors will later go. 

 

My instinct is to take the size of a door, add 40mm to both sides and the top and create an opening of that subsequent size. 

Base it on facts, not instinct!!!!!

Size of door at each opening, gap at each side, thickness of your chosen ( intended ) lining etc. Just beware that not installing the linings, and then plastering, will leave quite severe undulations from the floor to the head of the frame, and when you go to measure up and install the linings, you'll need to have measured the thickest part ( plastered surface > plastered surface ) to ascertain the absolute, correct size.

Most builders seem to forget this, and then the architraves and skirtings never line up properly.

[Nickfromwales]

Disclaimer : I have been drinking since 6pm so the brain is starting to get a bit wonky.

Maybe a spectator sport from herein for me tonight.  I'll edit this out tomorrow, and it'll be like it never happened 

 

Fullers "London Pride". Says "outstanding" on the bottle, and I damn-well agree. Just using it atm to wash down half a tub of Ben & Jerry's Choc Fudge ice cream.

 

"Happy times". 

[nod]

Normal opening heights are 2100 or 2035 

The majority of width openings  that I do in MF are 910 1010 Disabled 835 bedroom 710 cupboard 

[Tony K]

On 08/04/2023 at 23:47, nod said:

Normal opening heights are 2100 or 2035 

The majority of width openings  that I do in MF are 910 1010 Disabled 835 bedroom 710 cupboard 

 

@nod I'm thinking of buying some of these standard door lining kits, then build my metal stud wall frame tight around them in situ...

 

https://www.diy.com/departments/door-frame-set-2021mm-94mm/1451651_BQ.prd

 

In your experience, is that OK and do I need a timber inside the metal stud next to the door lining? 

Edited April 11, 2023 by Tony K

[Canski]

@Tony K what size studs are you using ?

[ETC]

On 08/04/2023 at 23:19, Nickfromwales said:

Base it on facts, not instinct!!!!!

Size of door at each opening, gap at each side, thickness of your chosen ( intended ) lining etc. Just beware that not installing the linings, and then plastering, will leave quite severe undulations from the floor to the head of the frame, and when you go to measure up and install the linings, you'll need to have measured the thickest part ( plastered surface > plastered surface ) to ascertain the absolute, correct size.

Most builders seem to forget this, and then the architraves and skirtings never line up properly.

Don’t forget the thickness of a door stop and the hinge.

[Nickfromwales]

11 hours ago, ETC said:

Don’t forget the thickness of a door stop and the hinge.

Yup. There is a nominal gap, for hinges etc, so that's always allowed for. Plus most openings are made 10-15mm oversized to allow for shims / packers to be installed to get the frames ( linings ) in plumb, eg to compensate for wonky stud walls etc.

[Tony K]

16 hours ago, Canski said:

@Tony K what size studs are you using ?

 

70mm.

[Tony K]

22 hours ago, ETC said:

Don’t forget the thickness of a door stop and the hinge.

 

But they will be on the inside of the lining, and so make no difference to the size of the opening in the wall, surely?

 

I'm working on the basis that the door lining kit marks the outside edge of the opening in the wall, and that I ought to butt the metal studs up to the lining then fix in place. 

 

I've bought a standard door lining kit and will see how it goes!