load-bearing walls

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If I was building a house with a truss roof I'ld tie the walls to the roof even though it's only for rigidity.

If you had a 4 meter long wall that formed a corridor, the only way to stop it flopping about would be to secure it to a truss. The cornice is not going to secure it enough...

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Hmmm then you would be expecting the walls to bow just a bit when the roof load went on I guess?

If by "secure" you meant locate a cleat either side of the wall to creat a "slip" joint which allowed the truss to remain clear of the top plate when fully deflected, then you would have a perfect job!;)

Seen plenty of structural cornices too, and they usually have a life of about fifteen minutes after the last coat of paint has been applied.

Sorry if I'm being a smarty pants, but trusses are not designed for intermediate support, and there are a number of ways of tying the wall top plates using ceiling battens to stop them wandering, without risking damage through inappropriate detailing.

Cheers,

P

Hi,

Well I've gone back over removing that wall and still think we we're ok. Hope I haven't hijacked the original post but for anyone interested here's why I think there was no load on the wall we removed.

The brackets used to secure the wall to the rafters were very lightweight as was the timber top plate. If these were supposed to hold weight I would have expected sturdier construction.

Having an archway in the middle of this wall meant there was no consistant frame throughout, I think it required some support from above to help support the arch and to stop the wall from moving.

There was no bracing or prop meeting the rafters directly above the top plate.

In another part of the house there is a span between walls equal to what there now is in my loungeroom. There is no difference in the roof trusses between the two areas. This suggests the trusses are able to sit above that span with no probs.

When the wall was gone we found the stud where it met the external wall was swinging in the wind - not connected to anything underneath, only being held up by the top plate and a nogging. If this was load bearing I would have expected that to show before now.

My qualified carpenter/builder mate agreed with all this and in any case there is now a bloody great beam bolted to the underside of the top plate sitting on double studs which are supported on the floor bearers.


How else would you secure a wall in a house with a trussed roof? Would cornice be enough? In regard to the inner wall supporting the outside wall would another wall butting up to the outside wall 3m away do that job? Any other feedback would be welcome.

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Originally posted by bitingmidge

and there are a number of ways of tying the wall top plates using ceiling battens to stop them wandering, without risking damage through inappropriate detailing.

Cheers,

P

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Ceiling battens?
I havent seen those used in Vic for many years, unless you are haveing a tin roof with trusses at 900mm centres, then its only the tin type of battens, which wouldnt hold anything.
Cheers, Allan

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Originally posted by bitingmidge
Hmmm then you would be expecting the walls to bow just a bit when the roof load went on I guess?

If by "secure" you meant locate a cleat either side of the wall to creat a "slip" joint which allowed the truss to remain clear of the top plate when fully deflected, then you would have a perfect job!;)
Seen plenty of structural cornices too, and they usually have a life of about fifteen minutes after the last coat of paint has been applied.

Sorry if I'm being a smarty pants, but trusses are not designed for intermediate support, and there are a number of ways of tying the wall top plates using ceiling battens to stop them wandering, without risking damage through inappropriate detailing.

Cheers,

P

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How well it works depends on the type of connection you make between the truss and the top plate, and also on the type of truss you have in the roof.

You can get angle brackets (i'm almost sure of) that you nail securely onto the top plate, and allow vertical movement of a truss.

It also depends on the type of truss that you have in your roof. My parents house has 3 trusses in it, which run the -length- of the roof - one for the center ridge, and two either side at the mid point of the slope. They are certainly tied to the top plates. It's quite a nice design actually - it's quite easy to move around inside the roof, and still provides strength for large open internal spaces.

I know that cornice wouldn't hold anything - I was just making a joke :-)

Trusses are designed to span the walls on which they sit and should not to be bearing on anything else in between. The way you are 'supposed' to do it is to use a batten on either side of the bottom chord of the truss like Biting Midge said.

If for some reason you are not using ceiling battens, presumably meaning you are fixing your ceiling directly to the bottom chord, then you'll need to find some other way that does not involve securing the top plate to the truss, perhaps the brackets that Dale mentions. I hope your trusses are nice and straight.

Jimmyjames, all I can say is that hanging a top plate off a truss to support an archway sounds dodgey to me but if your roof is a trussed roof, then it's not going to fall on your head if you removed it. It is a trussed roof, right? You mention both rafters and trusses in your posts.

My last post on this I promise!

Yes it's a truss roof - my builder friend has been inside the roof and made sure of this. If I used the wrong terminology I'm sorry, I meant the underside of the roof frame / truss as opposed to a rafter. I put the N in novice I can assure you but I never would have touched the wall if I wasn't told it was a trussed roof.

Thanks to all who replied and sorry if i hijacked the post.