Guidelines for Installation: Paving Slabs


Vanstone Paving Slabs are precast concrete paving blocks in different sizes from 300 x 300mm and larger and also round Stepping Stones. The slabs are mostly 50mm thick and are available in smooth natural grey, coloured concrete or with an exposed aggregate finish.

Vanstone Paving Slabs are for pedestrian use but, depending on the preparation of the paving foundation, may be allowed to take occasional light vehicle traffic. Heavy vehicles may damage the slabs.

Vanstone is not liable for the integrity of paving that has not been installed strictly according to the requirements and used within the limits set by this specification. If any doubt exists, the services of a qualified professional engineer with local knowledge should be employed.


Instructions for installation

Always survey and plan the installation well, taking into consideration required drainage and position of lines and patterns.

For Pedestrian Traffic Laid on Natural Ground

The substrata must be of a sufficiently sturdy and stable soil type like gravel, clay free soil or pure hard core filling. Expanding clay, silt, collapsing sand or other soils with poor bearing capacity or with unstable characteristics must be removed to a sufficient depth and replaced with suitable soil. Consult with an engineer if in doubt.

Loosen the subsoil to a depth of 150mm and re-compact at optimum moisture content to at least 90% of the modified AASHTO density to the required level. On top of the compacted layer, use a 20mm to 25mm bedding layer of clean river sand or crusher sand with 10% cement mixed in. Spread evenly over the surface and level.

Lay Paving Slabs and bed-down thoroughly by wriggling each slab a few times left and right. Test evenness of bedding by pressing down alternatively on opposite corners of each slab to determine if any see-saw action occurs. Each slab must be bedded evenly over its whole base and no gaps may be left.

If straight lines are required, the slabs should be laid using a fish line or straight edge.

Leave joints of 10 to 20mm wide between slabs and grout with a semi-dry mixture of cement and river/crusher sand. Use a mix ratio of 1 cement to 3 sand. Work into each joint and compact to ensure that no voids are left. Smooth down the tops of joints by stroking firmly with a brick joining tool. Remove any excess grouting material.

For Occasional Vehicle Traffic Laid on Natural Ground

This method is not for road type traffic. It is more suitable for domestic driveways provided no heavy vehicles are allowed.

Effect substrata preparation as above but with a final layer density of at least 93% AASHTO. Lay and bed Vanstone Paving Slabs in a 20 to 25mm thick slightly moist bedding mixture of river/crusher sand as above to which was added 20% cement. Keep slabs clean while working. Bed-down as above and allow to cure for 24 hours before grouting and final cleaning.

Paving Slabs Laid on a Concrete Slab

If Vanstone Paving Slabs are to be laid on a concrete slab, it is preferable to use a more rigid and permanent method of installation. In this case put down a 1:4 cement screed, compact and level as usual for a tiling screed. Lay the Paving Slabs as for floor tiles using a cement slurry while the screed is still moist (the same day). Lining up and bedding down is important.

Grout the joints and clean as above.


Important: Cleaning and Sealing

Immediately after a section of Vanstone Paving Slabs has been laid and cement was used in the process, the paving must be cleaned off of all cement residues to prevent staining. This must happen within an hour or two as cement-setting will render cleaning very difficult. Use clean water and a sponge.

If the Paving Slabs are to be sealed, it may be a good idea to apply one coat of sealer before installation to help protect it against staining.


Flexible Paving for Pedestrians

This method is not at all suitable for heavy loadings like vehicles.

If a completely flexible installation is required, then no cement must be used. Lay Vanstone Paving Slabs on a pure river/crusher sand layer of 20mm to 25mm thick. Bed in properly as above and fill joints with suitable sand, stone chips or even soil. Joints can be as wide as preferred to let water through for example. It may even be planted with grass as long as the fill level is below the tops of the Paving Slabs.