Thanks and I agree, Neither can I with regards to the mixing, that`s why we used clay where we can, so many chemicals in use when building today its a right toxic mix if your not careful. The value doesn`t come into it, not price wise anyway. Up here in the remote North west of Scotland dumping stuff just creates an eyesore in an area of outstanding beauty, licensed tips are very few and far between and it would only go to landfill anyway, returning to store involves a 350 mile round trip. So we will try a test area, it was interesting, we tried to give it away to fellow builders, but even though it is in date, been stored properly and was free, no one could be bothered to collect it and use it on another job, I can see why there is so much wastage in the building trade now, tried to give away lots of surplus building materials over the years, but unless its nearly a truckload of stuff or a pallet full of timber no one wants it, which tbh I found a bit of a surprise at first, now I know better, time is money and that rules just about everything. If we can`t mix it, it could have been used as a fertilizer being just like a powdered gypsum, bit like plain plasterboard waste, but there are so many chemicals in them now they just poison the soil, and water so can`t use it that way either. I hate waste and like to repurpose or recycle everything for my kids sake but hey ho you can`t win em all. Thanks for the reply anyway.