I have laid some sandstone slabs on my conservatory floor and I now want to grout them.However the limited colours available do not match with the slabs we have put down.I have put some slabs outside on my patio and I have pointed the joints with a mortar mix and it looks great.However,the mother in law has stuck her nose in and says that if I use mortar in the joints that the sand grains will come up.I intend to use a HG sealer on the slabs and pointing.Would this be OK - life wouldnt be worth living if she was proven right.
