Lime in building sand

[Thomzo]

I'm re-laying my patio at the moment. It's made of blocks set out on sand over clay. I'm having to dig down up to 9 inches of this so that I can flatten the area. I don't know what sort of sand they would have used when the patio was originally put down but if it was building sand, would it have had lime in it?

If I just throw the sand and clay over the retaining wall to build up the garden behind, can I just top it off with top soil and grow plants on it or is the sand still likely to be too limey? I particularly want to put my bay tree there.

I'm hoping it won't be too big a problem as the patio used to get a good crop of weeds on it regularly

Cheers
Zoe

[grahamhobbs]

If lime had been added to the sand, which is unlikely, it will be solid like a weak sand and cement mix. In fact it is more likely to have cement in it than lime. If the sand crumbles in your hand then it has minimal or no cement in it and can be safely used.

[Thomzo]

Thanks, that's a great help. The sand crumbles like, well, sand, so hopefully that should be fine. It's the clay underneath that's like concrete.

Zoe

[thesunflowergal]

Grrrrrr Swindon clay, I hate it!!