Building regs on timberwork for roof windows

[^woody^]

'rafter doubling' thing originally comes from

If you can prove by calculation that single rafters at that increased spacing can support the load of the window and trimmed rafters, you wont need to double the rafters.

Regulations don't and won't say "you must double rafters".

Regulations state that the components must be suitable for the loads.

 

[^woody^]

if you google regs4plans

Do they actually have a clue?

Do you work for them?

I would have thought googling a local authority website would be much better as a source of reliable information

 

[Designs.3DR]

Do they actually have a clue?

Do you work for them?

I would have thought googling a local authority website would be much better as a source of reliable information

No i do not work for them. Was simply answering a question from the OP.

Regs are across the country. Not per local authority. Best thing is to have structural calculations as that will provide building control the proof that whatever you are doing works structurally.

 

[^woody^]

The best thing to do would be to refer to any of the published structural guides or tables, which are intended to actually avoid having to instruct and engineer and avoid having to prove anything to the building inspector because such things are already proven!

 

[glock339]

Would a Sun Tunnel/Solar tube not do?

 

[noseall]

Hello,

I'm currently looking at putting some velux-type roof windows in my loft. It's not 'habitable' but used for a bit of storage so with the cost of electricity going through the roof (sorry) I'd thought longer term I'd be better off with some free light.

It would only be one or two small windows but I'd probably need to break into at least one rafter on each window (they're pretty narrow in my roof anyway). For building regs., everything I read talks about the trimmers and enclosing rafters needing to be doubled up. I've been scouring the regs and can't find any reference to this, maybe it is in a British Standard ? Or just some long held practice that's just become adopted ?

Any pointers as to where this originates from much appreciated. Then I can see what actually applies in my situation.

Many Thanks. Simon

Remove one rafter - add 1 more up each side.

Remove two rafters - add two more up each side.

...and so on.

It's as old as the hills.