What is the difference between bedding sand and polymeric sand?

Bedding sand (sharp/concrete sand) is the coarser layer pavers are laid and levelled on. Polymeric sand is a finer jointing sand blended with a polymer binder that sets hard once watered in, locking pavers in place and resisting weeds and ant erosion in the joints. Plain sharp sand works for joints in light foot-traffic areas, but polymeric is the standard choice for driveways.

How thick should the bedding sand layer be?

Most paver installation guides call for a 2.5 cm (1 in) compacted bedding sand layer. Thinner risks an uneven surface, while a much thicker layer compacts unevenly under the pavers and can cause them to rock or settle.

What is kiln-dried sand used for in block paving?

Kiln-dried sand is a fully dried jointing sand that is swept into the gaps between laid block paving and vibrated down to lock the units together. It is a distinct, finer product from the bedding sand the blocks are laid on.

Jointing Sand Calculator | Kiln-Dried Sand for Block Paving — Gibraltar

How Much Paver Sand Do You Need?

Paver sand covers two different jobs on the same project: a bedding layer the pavers are laid and levelled on, and joint sand that fills the gaps between them once they're set. Getting either quantity wrong usually means a mid-job supply run. This calculator works out both volumes -- plus the combined weight, bag count, and cost -- from your paved area, bedding depth, chosen sand type, and an optional joint-fill calculation.

How to Use the Paver Sand Calculator

Enter the length and width of the area you're paving.
Enter the bedding depth -- typically 2.5 cm (1 in) compacted -- and pick a sand type: sharp/bedding sand, polymeric jointing sand, or stone dust (limestone screenings).
Turn on joint fill if you need a separate joint-sand quantity, and enter the joint depth (roughly your paver's thickness) -- the calculator adds that volume to the bedding layer and returns total volume, weight, bag count, and estimated cost.

The Paver Sand Formula

Bedding volume = Area x bedding depth. When joint fill is included, joint volume = Area x joint-area fraction (the share of the paved surface that's open joint, typically 3-5%) x joint depth. The two volumes are added, a waste allowance applied, then multiplied by the sand's bulk density to get weight.

Worked example: a 5 m x 4 m patio (20 m²), 2.5 cm (0.025 m) bedding depth, sharp sand at 1,600 kg/m³, plus joint fill at a 4% joint-area fraction and 4 cm joint depth. Bedding volume = 20 x 0.025 = 0.5 m³. Joint volume = (20 x 0.04) x 0.04 = 0.032 m³. Total = 0.532 m³, or 0.585 m³ (about 0.77 cubic yards) with a 10% waste allowance. Weight = 0.585 x 1,600 ≈ 936 kg (0.94 tonnes) -- about 38 bags at 25 kg each.

Pro Tips

Worked cost example: for the 0.585 m³ (about 0.94 tonnes with a 10% waste allowance) patio example above, at a typical Gibraltar price of around £58 per tonne, that's roughly 0.94 x £58 ≈ £54 in material cost, before delivery.

Bedding sand and jointing sand aren't interchangeable. Sharp/bedding sand is coarser and meant to be screeded flat and compacted under the pavers; polymeric jointing sand is finer, with a polymer binder that hardens once watered in, locking the joints against washout and weed growth -- worth the extra cost anywhere vehicles will drive over the joints.
Compact the bedding layer before laying pavers, not after -- screeding it flat and firm first stops the pavers settling unevenly once foot or vehicle traffic starts.