Expansion and contraction in OSB is not a problem ( I think) As far as I know, no gaps needed in 18mm T+G OSB the expansion is built-in. The lower part of the T+G this doesn’t meet the other side; however, the top use so I don’t understand how that works! I know they are moving over to a new under T+G soon, but that’s all I know. I’ve tried reading the BS EN 1995-1-1:2004+A1:2008 Eurocode 5: ( 145 pages but went to sleep) Tongue and groove do I leave expansion joints The expansion per meter if it gets damp is recorded at.03mm so it’s not much we always leave a perimeter gape of 10 mm and push the bards together lightly; some never go tight as the edges are fragile and brake and bind. I’ve covered roofs over 100 m² and never had a problem, that said we don’t put rigid roofing material on the roof its normally rubber. I get lots of complaints from people that have had GRP glass reinforced plastic flat roofs installed. They constantly complain about the banging noise that comes from the contraction and expansion. Nobody seems to know if this is because of how the boards have [...]
GRP stands for ‘Glass Reinforced Plastic’ a material made from a polyester resin, which is reinforced by chopped strand mat glass fibres to form a GRP laminate. It is a very popular composite material to use due to the fact that not only is it very strong but also surprisingly light.
7 years ago we bought a 3 storey house in Pimlico with the intention of retiring there sometime around 2014. One of the attractions of the property was that the entire roof was a roof garden of some 45.1 square metres. We did the place up in order to rent it, which included installing a new GRP roof and new lead flashings. We then put timber decking over this as the walking surface of the roof garden.
Having viewed most of your videos on your YouTube channel, I’m wondering if you cover the Portsmouth area for a small flat roof covering? I’m planning a 7m x 3m extension utilising a warm roof construction I think. The roof will also have a 3m x 1m roof light in it.