Moving stud wall in vaulted room

[PapaMonyet]

Hi, I wonder if someone can offer me some advice. I'd like to move the stud wall back towards the Perlin to increase the size of the room. I'll gain almost a metre at each end if possible. I've just had a new roof fitted and the roofer said there wouldn't be an issue as the vertical beams were not structural. However the Perlin looks to be set quite low and although the struts are only nailed into position, who knows what was common practice 120 years ago. It isn't positioned over a load bearing wall, just nailed to the binder. Is it safe to move them?

 

[Tigercubrider]

I hope so - because I have a similar structure in my smaller bedroom.
The bedroom is half over the hall, half over the garage, and the roof slopes over the garage to single storey hight.
That meant that there was a big triangle of wasted space behind a fairly cold plasterboard wall.

What I did was to cut only some of them to create a cupboard with sliding doors, lined with 9mm? ply.
My reasoning was that the ply would provide some kind of strength if I was wrong. I also added a ton of insulation.

I am no structural engineer, but if the roofer says "ok" then go for it

 

[catlad]

They must be adding some support! what is the distance between the purlin I can see and the one above?

 

[PapaMonyet]

2.7m but although it is the same size as the lower purlin, 7x2 it sits over the cross members and below the rafters, directly below the ridge, see pic

 

[catlad]

I only see a ridge in that picture! So you are renovating an old existing attic room?

 

[PapaMonyet]

The room was part of the original construction, I own next door as well and both are identical. I was under impression beam marked with red arrow is Ridge and was told the one directly below was another purlin but appears to operate more on compression than on support to me

 

[catlad]

Ok well so only one purlin on that side, and quite low already, so that wall which you are deconstructing along with the collars ties are giving support to those rafters instead of another purlin.

 

[catlad]

If you are bringing the renovation up to current standards then why not sister some 6x2" timber to the original rafters and that way it will accommodate the insulation and allow you to move the wall back.

 

[PapaMonyet]

So far I've only removed the lath and plaster as it was pretty tatty. Surprised the vertical struts are only nailed to the side of the rafters and sit on the binder. Roofer said they weren't load bearing but can't get it right in my head. My binder sits on 6x2 joists, which would offer the structural support not usually found with a binder, the span is quite long above the purlin but rafters are only 3x2. The new roof is fibre cement so almost half the weight per metre than slate

 

[PapaMonyet]

Not sure how I'd sister 6x2 beside 3x2 with reroofing, I think I've missed an opportunity when I had mine done.

 

[PapaMonyet]

I meant without reroofing so it looks like the rooms staying the same size. Thanks for input Catlad.

 

[catlad]

No you should be able to sister some deeper rafters to the original rafter in situ, they don't need to go to the wall plate just from the ridge to the purlin, to which you could notch the bottom of the new rafter over the purlin. Then that gives you the option to put the wall where you like.