Hi all,
I'm in a position where a contracter has filled a flat roof but has used inadequate timbers.
The roof has a 5.7m span and he's used 45mm x 220mm at 40cm centres.
Looking at a table from BS 5286-7.2 there is only one timber that will span 5.764m at 40cm cetres and thet's 72 x 220 at a...