Lean to conservatory - Replace with a timber frame and lightweight tile roof - Advice needed!

[ingle]

I want to replace my polycarbonate conservatory roof with a timber frame and lightweight tile roof with either 1 medium or 2 small Velux windows then insulate it with Kingpan/Celotex foil insulation boards and get it plastered inside.

It is 4m length x 2.9m width in size.

Need advice on what size rafters I would need and spacing between each rafter.

And with it being windows all the way around, it should be fine to hold the weight of this new timber frame then lightweight roof? Yes?


Also any advice on the thickness of the insulation boards and where you leave a air gap would be great as I've read a lot of mixed information.

 

[Alastairreid]

http://www.rightsurvey.co.uk/rafters-span-tables/

The minimum pitch for most lightweight systems is 10 degrees.

The windows by themselves will not take the weight of the trusses, roof covering insulation and ceiling.

Google bay poles and ring beams.

 

[ingle]

Do you not think? If I had a wall plate bolted on the solid wall and the rafters rested on that and also down to the far side of the conservatory. The sides would also be used for support.

Would an aluminum frame be lighter and better to use? If so where is best to buy those from online?

 

[gordon daly]

hello, not a reply but could use similar advice. Im new here so please excuse errors. I am self building a single story rear extension. Design and pricing stage. For the current regs, is there anything wrong with this approach:
2x8 rafters spanning 3.2 meters with a 1.1M rise giving a 19 degree pitch. 150mm celotex insulation leaving a 50mm air-gap (not sure about this). Clay tiles suitable for this pitch.
Also, width of extension is about 8M and I assume 400 centres for rafters, doubled around vellux windows.
Any problems with the above? also any advice regarding rafter trusses or fixings and membranes for this pitch of roof would be welcome. Thanks.

Read more: https://www.diynot.com/diy/conversations/add#ixzz4cQlAl1Mv

 

[catlad]

Sounds ok for the most when you say clay tile do you mean plain tiles?