Garden guide
Sharp Sand vs Building Sand: What's the Difference?
The short version
Sharp sand (also called grit sand) is coarse, with angular grains that lock together and drain freely — use it under paving and in concrete. Building sand (soft sand) is fine and smooth — use it for mortar, pointing and render. They are not interchangeable: the wrong one gives you weak mortar or a soggy, shifting paving base.
How to tell them apart
Grab a damp handful. Sharp sand feels gritty and falls apart when you open your hand. Building sand feels smooth and holds a ball shape when squeezed. Ignore the colour — red, yellow and white sands come in both types depending on where they were quarried.
When you need sharp sand
Bedding patio slabs (a 5cm layer over compacted sub-base), mixing concrete for posts and bases, floor screeds, and improving drainage in heavy clay soil. Its angular grains leave gaps that let water through — exactly what you want under anything structural.
When you need building sand
Mortar for bricklaying and blockwork (typically 4 or 5 parts sand to 1 part cement), repointing, and render coats. The fine grains make a smooth, workable mix that trowels cleanly. Never use it under paving — it holds water and moves under load.
How much to order
The maths is the same for both: area (m²) × depth (cm) × 10 = litres needed. A bulk bag holds about 730L and weighs around 850kg. Our sand calculator works out the volume and compares bulk bags against handy bags for the best price.