DIY Doctor UK DIY Forums

When can you use a dry mix of concrete and sand. I am building a patio and have a hard core base. Can I put a dry mix of sand and cement on it, allow it to harden and then put slabs on it?

I would add some water to it and lay the slab,and tap it down with a rubber mallet

You need a wet mortar mixture of mainly building sand mixed with cement. You can add a shovel or 2 of sharp sand into a mixer. Have the mixture wet to apply the slab to stick to it while you tap them down with a rubber hammer and to the right levels.

Also don't dot/dab or five spot the wet mix I would recommend full cement beds. Do the outside then add a bit in the middle