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Permeable Surfacing Guidance

How to Lay Clay Pavers

A well designed and professionally installed Clay Paver patio, path or driveway should last a lifetime. The Chelmer Valley team are experts in all aspects of Clay Paving and have vast experience in the installation of all of our products. We have put together this handy guide on the professional installation of Clay Pavers for a domestic patio, path or driveway. If you need any further information or have any questions on the installation of all of our products, please contact a member of our sales team.

Getting Started

Depending on the site, you may need to carry out some initial excavation, to a depth that accommodates the sub-base, the bedding (or ‘laying’) course and the pavers themselves. The end result will need the pavers to sit at least 150mm below the damp proof course (dpc). See below diagrams for cross section of finished install.

Patio/path

60mm paver
30-40mm sharp sand bedding layer.
100mm compacted MOT type 1.

Driveway

60mm paver
30-40mm sharp sand bedding layer.
150mm compacted MOT type 1.

You will then need to construct a sub-grade, sub-base and bedding course before laying the pavers. Each course must be compacted and levelled before the next can be applied.

Prepare Your Sub-grade

If laying a drive on new ground, or constructing other paved areas where ground preparation is necessary, a well-prepared sub-grade will ensure that the bedding course will be as dry as possible. You may also need a draining foundation where the groundwater level is within 500mm of the surface.

To prepare a sub-grade, excavate to the correct depth (see above) and remove any material that will not compact easily, such as large chunks of rubble. Replace any material removed with suitable material to meet the specifications for the site. Compact the sub-grade until it is as level as possible (no more than 20mm divergence). The sub-grade will need to be wide enough, bearing in mind the edge restraints and any adjacent structures. If you are in any doubt as to what materials you should use, or how thick the sub-grade should be, please contact us.

Construct Your Sub-base

Using Type-1 stone material that is well-graded, compact the sub-base in layers. Each layer should not be thicker than 75mm and each layer must be fully compacted before the next layer is added and compacted. Continue to add layers until the required minimum thickness is reached (this will vary and depend on the quality of the sub-grade and the frequency and weight of traffic loadings on the site – contact us with any queries about this).

Again, thickness should be uniform with not more than 20mm divergence – typically, a domestic sub-base should be around 150mm deep on good, solid ground, but site conditions may mean that your sub-base will need to be thicker.

For any questions about how to construct your sub-base, contact us and we will endeavor to help. Full guidance can be found in BS7533.

Edge Restraints

In order to hold the bedding course and pavers in place you will need a a rigid edge restraint around the perimeter of the area to be paved. Existing walls may be used, or pavers can be used.

The edge restraint should be laid on top of semi dry mix made up of 4/5 parts sharp sand and 1 part cement. A 45 degree haunch using the same semi dry mix should then be applied to the outside edge of the edge restraint to hold it in place.

Bedding/Laying Course

Once your ground is prepared with a sub-grade and/or sub-base and edge restraints are fitted, lay the bedding course of well-graded, moist grit sand (not building sand) of 40-50mm. You should be able to squeeze the sand in your hand without water escaping, with the sand holding its shape when released – this will prove that the sand has the correct level of moistness. Compact the bedding course and screed to level the surface.

If you have to leave the work overnight at this point, ensure that the sand is completely covered to prevent the sand becoming too wet or moist through dew or frost.

Paver Course

First, unpack the pavers. Open several packs to ensure a good, even blend of colours and unpack each diagonally rather than horizontally – this will ensure that any minor variations in the colour or pattern of the pavers will be distributed evenly across the area. Any pavers damaged on site should not be used, but can be used for cuts if appropriate. Ensure that you unpack the pavers onto flat, even ground, and ensure that you wear appropriate safety-wear to prevent injury from falling pavers.

Decide on the pattern of pavers to be constructed. This may be a simple matter of aesthetics, but if the paved area is to be used by vehicles then an interlocking pattern will prove most stable. We can provide more suggestions on laying patterns on request. If working on a slope, begin at the bottom of the slope and work upwards – if the gradient is particularly steep you may need to use intermediate restraints, for example a row similar to edging cemented into place at set intervals.

Fit whole pavers first, and complete using the cuts. For herringbone patterns, start in the centre and work to the edges, cutting there as necessary. This will avoid the pattern going out of line. Where there are gaps (e.g. around a curve), you will need to cut down full pavers to fit. Any such in-fill pieces should be cut as accurately as possible, using a disc cutter and fitted flush with the whole pavers wherever necessary to complete the paving pattern or to fill the entire area. Ensure that safety goggles are worn and that correct safety precautions are taken. The joint width between pavers can be between 2mm and 5mm. Each paver or in-fill should be not more than 2mm higher or lower than adjacent paving bricks. Using a 3mm rule, ensure that overall there is not more than a 7mm deviation of the laid surface. Any more than this could result in the pooling of water every time it rains and will ultimately destabilize your paving.

Compaction

Just as the sub-grade, sub-base and bedding courses were compacted to ensure a solid finish, the pavers will now need to be compacted. Before doing so, though, use a brush to sweep dry, fine jointing sand (ideally, crushed sand of 2-4mm grade) into the joints between the pavers. Brush away any surplus sand.

Compact the pavers onto the bedding course using a vibrating plate compactor that is fitted with a rubber soleplate to avoid damage to the pavers. If damage does occur, replace any broken or cracked pavers and re-fill with jointing sand before re-compacting that area.

Check again that the difference in height between the pavers is never more than 7mm across the entire area, to avoid pooling (as above). If compacting has caused some deviations, correct these by re-adjusting the pavers.

Final Joint filling

Once the pavers have been compacted and are as level as possible, brush another layer of dry, crushedsand (2-4mm grade) into the joints across the whole area. Repeat until all of the joints are completely filled and the pavers are immovable. Brush a final layer of fine sand (0-2mm grade) into the joints to finish. Your paving is now ready for traffic.

Maintenance

Clay paving is easy to maintain and requires little time to be spent on it once it has been correctly laid. High-pressure washing systems or diluted bleach can be safely used periodically to keep the pavers clean and free of algae. Acid-based cleaners should be avoided. To maintain the pavers to a high standard, wash occasionally using a hard-bristled brush and hot, soapy water, and regularly remove or kill any weeds that may emerge between the joints. When using a brush or high-pressure cleaner, ensure afterwards that your joint filling is still intact. Replace or top-up if necessary.

Care

If you follow the procedures set out above, your paving will last many years and will require little maintenance. If however, our guidelines have not been followed then we regret that we cannot accept liability for any problems that you might incur.

Please also note this is a generic guide, you may have individual circumstances, considerations that may alter these parameters. When in doubt, seek local advice from an engineer or paving professional. If in any doubt at any stage as to how to proceed, please contact us for advice.