We’ve been renovating the bathroom and have a lot of gib leftover. I read that you can use leftover gib to help clay soils drain better and also de-clump which will be better for my new berry plants. I left the gib out in the rain to soften it a bit then I got a hammer and smashed up the gib and stripped off the paper then smashed some more and now I had powderish clumps. I then poured this over the garden and will dig it through with some compost. This will improve the soil quality and will make the soil better for my new raspberry and blackcurrant plants. Yummy my berry garden has begun.