I have a solidly built blockwork double garage 5x6m (build by a previous occupant) incorporating two massive 10"x5" RSJs, one across the opening the other across centre. Joists are 115x50 softwood at 600 centres and all sound. Unfortunately the the roof boards and felting are anything but solidly built. The boards are chipboard and the felting has obviously been done badly and has been leaking over most of one corner quarter probably for years. There is negligible slope.
The question is whether to create some slope and go for a sheet system or stick with the nearly flat and replace boards and just use a good quality vinyl membrane or any other suggestion. We're ruling out any kind of pitched roof because of cost and planning. It needs to be done on the smallest budget possible but at the same time must be very sound and durable. Can do the work ourselves if it would seriously reduce the cost as we have decades of building and engineering experience to high standards but no experience/equipment for any highly innovative or exotic techniques in flat roofing.
Many thanks for your help in advance. PeterM
The question is whether to create some slope and go for a sheet system or stick with the nearly flat and replace boards and just use a good quality vinyl membrane or any other suggestion. We're ruling out any kind of pitched roof because of cost and planning. It needs to be done on the smallest budget possible but at the same time must be very sound and durable. Can do the work ourselves if it would seriously reduce the cost as we have decades of building and engineering experience to high standards but no experience/equipment for any highly innovative or exotic techniques in flat roofing.
Many thanks for your help in advance. PeterM