Over span joists/ceiling binder

[23vc]

Hi
After a bit of advice on the best approach for ceiling joists on my extension, it's about 6.5m front to back and will have a gable end and a normal up and over roof to match the existing house.
Planning on cutting the roof myself not using trusses.
Ceiling joists will run front to back (assume they have to ?) so 6x2s are obviously well over span. Building control have mentioned 9x3 ceiling binders, just wondering if there are other options as that's a hell of a heavy piece of wood to get up there. This kind of extension is pretty common so really keen to know what's normally done. Any advice appreciated as always!

 

[John D v2.0]

I guess it's a side extension right? What is the width?
If you have a structural ridge you can run the ceiling the other way which would help with later conversions if applicable, if there's no chance you'll want to convert, then you can use a small eg 4 by 2 binder and hang from the top of the ridge on every joist of needs be, thereby making it much lighter. Or even just do away with the binder if that, but if that you're making you're own truss in a way!
Edit: that doesn't answer how it's usually done, I suspect the answer is a truss!

 

[tony1851]

Inspectors just read from the published TRADA tables for joists. For ceiling joists, these tables assume a live load for loft storage of 5lbs/sq ft.
If your loft is inaccessible for storage (eg too low, or no hatch) then there is technically no live load to take into account, and the joists can span a longer distance.
Also, if you can space them closer together (say 350mm), that helps.

 

[23vc]

Thanks guys. Yeah it's a side extension. Width is 3m. I may be wrong but I suspect a structural ridge won't be any easier in terms of lugging big beams up there. The loft won't be accessible.

 

[^woody^]

Use a smaller binder and drop some hangers down from the rafters.

 

[23vc]

Thanks woody when you say drop hangers down is that like a long restraint strap or pieces of wood?
I might look at getting trusses made but don't like the idea of getting them up there and would really like to attempt my first cut roof

 

[tony1851]

(Woody's probably still asleep with a hangover at this time of the morning, so I'll chip in);

In traditional cut roofs, ceiling joists are often supported by having a binder (eg a piece of 100x50) running across the top of
them roughly at mid span, and nailed or screwed through. The binder itself is then supported by timber strips (eg 100 x 25 - sometimes they would use any old bits of scrap, such as lengths of floorboarding etc) nailed up to either the ridge or a purlin.
The loads are not high so it's a case of just preventing excessive bend in the ceiling joists.

 

[tony1851]

Typical old roof - can't see the ceiling joists and binder, but you can see the strips supporting the binder off a purlin.

 

[23vc]

Thanks Tony so that may be my best option, I'll discuss it with building control

 

[freddiemercurystwin]

(Woody's probably still asleep with a hangover at this time of the morning.

I always assumed he never stops drinking?

 

[John D v2.0]

Oh yes hanger that's the word I was after! Only part of a roof that's named in a way I can understand

 

[^woody^]

I always assumed he never stops drinking?

It's the people on here that drive me to it.