Loft Divide - Should it stay or should it go?

demontfort

Hello,

I would like to create a bedroom in my loft. It's all fully boarded out with one half insulated and the other half still having exposed rafters. The two parts are separated by a stud wall and tiny door which even Ronnie Corbett would stoop to get through. On the uninsulated side you can see the wall and door are built around a frame running from the ridge down under the purlins. I'd  like to remove the wall and frame to make into a single room. However I don't know if this divide was only created to separate the insulated and uninsulated part or if the frame is part of the roof support. Therefore I'd like to know if anyone has ever seen this type of structure before, if it has name and if there is any way of checking if it's supporting the roof. I had a roofer look at this today and he was none the wiser and I haven't had much luck with structural engineers in the past. Any suggestions, however wayward are most welcome.

Thanks,

DM

travis-powers

The big timber frame is supporting the purlin, you would need to involve a structural engineer to see if anything could be done about it.

plumb1_2

And feed that Reindeer 

Section62

demontfort said:

However I don't know if this divide was only created to separate the insulated and uninsulated part or if the frame is part of the roof support. Therefore I'd like to know if anyone has ever seen this type of structure before, if it has name and if there is any way of checking if it's supporting the roof. I had a roofer look at this today and he was none the wiser and I haven't had much luck with structural engineers in the past. Any suggestions, however wayward are most welcome.

The big bits of wood are there to support the roof, not divide the room.  The most likely scenario is someone wanted to convert the loft, but some major structural work would be required to do it properly, so they only converted the first part fully.

The vertical post in the centre of the roof is a form of king post (search "king post truss").  I  have a horrible feeling that originally the post went from ceiling to ridge and someone has cut the lower part out to make the 'door' access.  Does the underside look as though it has been sawn through in recent times?

However, it is also possible that no alteration has been made - the shoulders of the post sit on the two diagonal members which might be enough on their own to carry the load down and out to the walls.

You really need a structural engineer to take a look and give their opinion on what to do - not just about the feasibility of opening the space up, but also a check that no alterations have been made which seriously weaken the roof structure as it is.

grumbler

I'm fairly sure the new studs and the door frame can be safely removed, but this won't help to make the triangular  passage much higher.

Also, I suspect that the roof insulation in the converted part is inadequate and doesn't meet modern requirements (IIRC 100mm rockwool between the rafters plus 100mm celotex-like under). It can possibly be 150mm of celotex between the rafters, but I think they aren't deep enough for this as you need a ventilation gap under the membrane.

demontfort

Thanks all for your answers, yes the king post has been cut away which doesn't surprise me as the previous, previous, owner was well known locally as a DIY bodger, I'll see if I can find a decent structural engineer to take a look. The insulation probably isn't up to scratch but fortunately building control don't need to sign off on this part of the loft as if I do manage to join the rooms I won't be looking to classify this as a bedroom. However it's a big If and if I can't get the rooms joined then Rudolf the Reindeer will be left to rule the roost, don't worry there's plenty of dust up there for him to graze on.

ashe

Just be glad it's just a reindeer 

My old loft was like a horror movie. Crayon holder fixed to wall, a kids dart board and a hand made doll nailed to the top rafters. I never once lifted its head as that's how you die.

left it there when I moved out 

grumbler

demontfort said:

...yes the king post has been cut away which doesn't surprise me as the previous, previous, owner was well known locally as a DIY bodger, ...

And now I'm not sure any more about the studs....

TELLIT01

If the doorway is so small that Ronnie Corbett would have trouble getting through I don't see how you could convert the space into a bedroom.  There simply wouldn't be the required headroom.

Section62

demontfort said:

Thanks all for your answers, yes the king post has been cut away which doesn't surprise me as the previous, previous, owner was well known locally as a DIY bodger, I'll see if I can find a decent structural engineer to take a look.

100% a structural engineer job then.

King post construction types can have the post either in compression supporting the load above (aka 'crown post'), or in tension supporting the ceiling tie below.  If your case is the latter then the weight on the loft floor would in principle be supported by the now absent king post.  You need to know what the king post did before it was cut, and whether the correct alternative structural members were added to support the ceiling and roof.