Ask a Tradesman
What rafter sizes do i need to use on a mono pitch roof which is 7.8m long by 4m span. got to have slate roof.
minimum 6x2 but 7x2 or 8x2 would be better
Answered 2nd Jan 2013
Defintely go toward 7x2.
A recent building control officer recommended this on that sort of span a few weeks ago.
Answered 28th Jan 2015