Has anyone got a wooden outdoor playhouse in the garden built straight onto the grass? Google suggests it’s ok to do this if the wood is treated and the bottoms moisture proofed. What did you use to treat the wood? How has it lasted, i.e. has the wood gotten damp/mouldy/rotten? Is it better to put loose paving slabs down over the grass and build playhouse on top of those? Or another idea? Thanks