Building Sand vs Sharp Sand For Patio

[EViS]

Marshalls are recommending we use a mortar bed of 4 parts builders sand to 1 part cement for laying our paving. Why are they recommending builders sand over sharp sand?

They don't seem to want to answer that question .

 

[misterhelpful]

Builders/soft sand gives more pliability to the mix and will grab the slabs much better than just sharp sand but sharp sand gives a more solid bed.

I've always used a mix of 3 parts sharp sand, 2 soft, and 1 cement when I've laid patios and it's worked fine but I'm not a builder so there might be better advice out there.

 

[Space cat]

I'm not a builder either but, in the absence of any better advice, I would go with Tommy Walsh's special grouting mix; that's two parts sharp sand, two parts fine sand and one part cement. As its name suggests, it's also ideal for filling the gaps between the slabs.

 

[r896neo]

try making a 50mm thick lump of building sand and then one of sharp sand, after a couple of days to cure you will be able to see how much stronger the sharp sand mix is. Building sand is also bad news because it holds much more water giving increased risk of staining both on the surface and from water bleeding though natural stone.

Personally i lay on screed mixed up wet which i get delivered, If i mix it myself i use plastering sand.