I am currently working out a roof design as follows - 15' lean to roof, rafters spanning 3.8m, supported mid span by a purlin. I have sized the rafters and purlins using Trada tables based on the assumed loads, my questions are as follows:
Am i right in thinking that I DO NOT NEED joists to tie the feet of the rafters, due to it being a lean to roof?? i.e. I could form a vaulted ceiling if desired.
My main question however is that, if I decided to go with a flat ceiling - how would I install the joists, given that they are not required as part of the roof structure?
Any help would be great!!
Thanks
Am i right in thinking that I DO NOT NEED joists to tie the feet of the rafters, due to it being a lean to roof?? i.e. I could form a vaulted ceiling if desired.
My main question however is that, if I decided to go with a flat ceiling - how would I install the joists, given that they are not required as part of the roof structure?
Any help would be great!!
Thanks