the DIY project 'FLAT ROOFS:- HOW TO BUILD PROJECT'
http://www.diydoctor.org.uk/projects/bu ... t_roof.htm
mentions span tables for flat roof construction, and says these are available at the stationary office, however the exact name of the £10 publ. is not mentioned, and searching their website Google "tsoshop.co.uk"
brings up many matches but it's not clear which is the correct one. Any ideas?