Lean to Timber Rafter Size

[1975bloom]

Hi, first question, I have a Lean-To Conservatory W 5.3m x Projection 4.5m that I want to change the roof to a light weight tile roof. The conservatory has 6 x 2 timber rafter space at 700mm. A builder told me to put new 8x2 rafter in space at 400c but can I just add extra 6x2 rafter so spacing will be 350mm or double up the rafter, as this is going to be light weight tiles. Many thanks

 

[chappers]

Not really, what is the pitch of the roof, even 8x2s are really underspeced for 4.5m span even at a 30-45 degree pitch.
More importantly you say it's a conservatory, is the actual structure capable of taking the extra weight of the rafters and roof

 

[1975bloom]

Not really, what is the pitch of the roof, even 8x2s are really underspeced for 4.5m span even at a 30-45 degree pitch.
More importantly you say it's a conservatory, is the actual structure capable of taking the extra weight of the rafters and roof

Hi, thanks for replying, its hardwood timber frame with dwarf wall on 2 side and a full high wall with double glaze window and door, I think the pitch is 10 degree. I have 6x2 rafter and had no problem, the conservatory is 15 years old.

 

[chappers]

trada tables say that 8x2 is just about OK. whats the roof currently made out of?
Your other issue is that 10 degrees is into flat roof territory. There aren't many slates or tiles that work at such low pitches.

 

[1975bloom]

trada tables say that 8x2 is just about OK. whats the roof currently made out of?
Your other issue is that 10 degrees is into flat roof territory. There aren't many slates or tiles that work at such low pitches.

Hi, Its c24 6x2 timber painted with polycarbonate sheets, I want to put lightweight conservatory roof tiles on.

 

[chappers]

seems there are some products that will probably work for you superlite being one and some of their range works down to 10 degrees. sounds like doubling up your rafters may work.

 

[1975bloom]

seems there are some products that will probably work for you superlite being one and some of their range works down to 10 degrees. sounds like doubling up your rafters may work.

I hope so, Thank you for your help, .