No homeowner wants to discover that they have a leaking roof. Thankfully, many original Victorian roofs have stood the test of time, largely due to the use of high quality materials. With older properties, however, it is important to makes regular checks for potential problems and deal with them before disaster strikes. This feature is an edited extract from the Victorian & Edwardian House Manual by Ian Rock, published by Haynes. Ian Rock is a chartered surveyor and director of survey price comparison website rightsurvey.co.uk If up in the loft you can see the undersides of the slates or tiles fixed to thin rows of timber battens, then your roof is likely to be original. Although some roofs in more expensive later Victorian houses have timber ‘sarking boarding’ laid over the rafters, the practice of draping sheets of underfelt beneath the tiles as a secondary line of defence is a relatively modern concept – previously any moisture seeping through in stormy weather would have dried out thanks to lofts being well ventilated.  Damp problems can occur where old roofs have been re-clad and underfelted, unless ventilation is improved to compensate. Modern ‘breather membranes’ are ...