Timber conservatory roof with no wall plates?

[pharmjoi08]

Hi,

Am having a builder put up a conservatory with a solid timber roof and am quite concerned about the spread weight of the roof (also having two velux windows in the roof).

As you can see from the picture, at the moment they have the joists resting straight onto the frames so clearly they are not planning on putting in a wall plate, any ideas if this is acceptable or if this is going to be a recipe for disaster?

 

[sxturbo]

Should have a plate going across to spread the weight.

In theory it may be ok as the roof weight may not be much. But I doubt it will be ok

 

[noseall]

A wall plate will help dissipate the downward thrust from each rafter, over a larger area, meaning your opening lights will still work. If it is well fixed, it may even prevent uplift as long as the plastic components are secure. It does not however counter the spread of the roof.

In theory it may be ok as the roof weight may not be much

It's not just dead loads or even live loads or snow loads but also wind loading to factor in.

I see there are collars - which will help a bit I suppose.

 

[catlad]

Why you wouldn't screw a 3x2" on top of the frames to start with is worrying.

 

[pharmjoi08]

Thanks all, should I insist on a wall plate or is it OK as is? There are collars and have said they're planning to put in a tiebar or two for the spread weight

 

[noseall]

they're planning to put in a tiebar or two for the spread weight

That'll look nice.

 

[Notch7]

I've designed and built many timber conservatories - I would never build on without a headplate/ ringbeam.

And why have they put up 2 common rafters before cutting to length? - I don't get that.


Judging by the pitched roof, it looks like it's only connected to the house at the narrow end.

That means the conservatory will be subject to wind loads on the 2 longest sides. The solid roof will help make the structure stiff as it will be fixed to the house.

Yes the conservatory will need tie bars - you can get them with stainless catenary wire now which look quite contemporary, rather than the old conservatory threaded rod covered by a tube type.

 

[pharmjoi08]

I've designed and built many timber conservatories - I would never build on without a headplate/ ringbeam.

And why have they put up 2 common rafters before cutting to length? - I don't get that.


Judging by the pitched roof, it looks like it's only connected to the house at the narrow end.

That means the conservatory will be subject to wind loads on the 2 longest sides. The solid roof will help make the structure stiff as it will be fixed to the house.

Yes the conservatory will need tie bars - you can get them with stainless catenary wire now which look quite contemporary, rather than the old conservatory threaded rod covered by a tube type.

Thanks for this, I asked them about the ring beam and they said they haven't put it in because they find that it can cause more spread and the frames can take the weight. I now don't know if they're right or not.