I've just had a survey done on my house and the surveyor has recomended that the roof is inspected and a report done. The roof is now in good condition as I recently repointed the ridge tiles and refitted 2 missing tiles.The roof which is constructed from slates without underfelt doesn't leak ( it was p*****g it down when the survey was done) but he still wants a report and the only reason I can think he's insisting on the report is because the slates back pointing is crumbling and some of its dropped out altogether,anyone have any thoughts why a report is needed on a water tight roof.