Sand for Block Paving and Cobbles: Which Sand to Use for the Bedding Layer

Where the sand goes in block paving

Put simply, a block pavement has three parts:

• Sub-base: the compacted supporting layer that takes the loads.
• Bedding layer: sand spread and levelled over the sub-base, where the blocks are laid.
• Joints: the gaps between blocks, which many systems fill with fine sand.

When people search for "bedding sand" or "sand for pavers", they mean the second layer. It is not what gives the pavement its strength (that is the sub-base's job), but it sets the level and supports the blocks evenly.

Which sand to use

Pit sand 0/4. Sold as extracted, without washing. Grains from 0 to 4 mm, placed on the market with CE marking (EN 12620, DoP on request). Its product sheet lists bedding and levelling layers, fill and outdoor work. Sold in big bags and 25 kg bags; see current prices on the pit sand 0/4 product page.

Coarse washed sand 0/4. Same grading, but washed. It also works for the bedding layer. Sold in big bags, 25 kg bags and, unlike the other sands, in bulk. For larger quantities, bulk is usually the cheapest format per tonne; see current prices on the washed sand 0/4 product page.

Fine sand 0/1 for the joints. When the paving system calls for sand-filled joints, a fine sand is used. Fine washed sand 0/1 lists "joints and detail work" among its uses. Always check with the block manufacturer which material they specify for the joints.

Thickness and compaction

The thickness of the bedding layer depends on the type of block, the use (foot traffic or vehicles) and the sub-base. Follow the project or the paving manufacturer's instructions.

In general terms, the sequence is:

• Compact the sub-base before spreading the sand.
• Spread the sand evenly and screed it level with a straight edge, without walking on it once levelled.
• Lay the blocks on the levelled sand.
• Compact the pavement with the blocks in place, as the manufacturer instructs, and fill the joints.

The sand should be free of soil, roots and building debris. If it is stored on site, keep it covered from the rain.

How much to order

The sum has two steps: area × thickness = volume (m³); volume × 1.6 = tonnes.

Example, only to illustrate the sum: a 40 m² patio with a 3 cm (0.03 m) layer, if that is the thickness specified.

Add a small margin for waste and level adjustments. The simulator (in Portuguese) does these sums for you; see also how to calculate the amount of sand and how much a cubic metre of sand weighs.

Delivery and collection

Delivery to site, within 24-48 h, is from 5 t across the Lisbon and Setúbal region (outside it, on request, also from 5 t). Below that quantity, as in the example above, the order is still taken, for collection at our sand pit in Seixal. Product page prices exclude VAT and delivery.