Construction of the Bedding Course
This work should never be undertaken in wet weather. Bedding sand is spread over the area in a loose non-compacted layer, slightly in excess of the finished depth.
A vibrating plate compactor is used to compress this layer which is then screeded using screeding rails, to the required level. The area of bedding course to be maintained in advance of the placement of pavers, is normally up to 40 metres square.
Only prepare the bedding course area which you will lay in one day and protection of an unlaid area is essential, when left overnight or before the onset of inclement weather.
The bedding sand is now ready to start laying the pavers. Once prepared, the compacted bedding course should not be disturbed.
Laying the Pavers
Prior to laying, pavers should be mixed from at least three packs if possible so as to blend the colours Seamlessly. The pavers are laid by hand on the prepared bedding course. There are many bonding patterns but the strongest is the herringbone. It is often useful to undertake a small trial area to determine the most economic use of pavers and to minimise cutting. There are two types of herringbone bond, 90 degree and 45 degree. Always start placing the pavers from an established straight edge such as a restraint. The string line is placed at 90 degree to the straight edge. Pavers are placed by hand to the predetermined pattern. The following points must be remembered when laying:
i) Stack unused pavers approximately 1 metre back from the advancing face.
ii) Check pattern regularly with string lines.
iii) Do not impose undue loads on to un-compacted pavers.
iv) Do not stand too close to edge of paver line. Set pavers about 10mm proud of edge restraints which on compaction will leave approximately a 5mm chamfer proud of the surface.
- Stack unused pavers approximately 1 metre back from the advancing face.
- Check pattern regularly with string lines.
- Do not impose undue loads on to un-compacted pavers.
- Do not stand too close to edge of paver line. Set pavers about 10mm proud of edge restraints which on compaction will leave approximately a 5mm chamfer proud of the surface.
Pavers to be cut should be handled carefully and cut using a specialist cropper which can be hired, or a diamond saw. Care should be taken to wear recommended protective equipment.
Always use kiln dried paver sand to finish off the job. The sand is spread over the surface and then brushed into the joints.
Surplus sand is removed and the vibrating plate compactor (with rubber mat installed) is then passed over the pavers two or three times. If an unfinished area is being compacted, the compactor must only go to within one metre of all unrestrained edges.
The pavers are normally compacted to the required level after two or three passes.
After this the whole sequence is repeated until all joints are full. All surplus sand is now removed and the area is ready for use.
Critical Points to Remember
The end result is only as good as the sub-base, so only use M.O.T. Type 1 or approved Granular Sub Base (GSB). Sub-base levels must be formed to required final profile. Use restraints to achive this.
Use Zone 2 concreting sand for the bedding course. Compact to correct levels. Construct a trial area in advance.
Start from a straight edge. Always use and frequently check string lines. Place pavers maintaining 2-5% joint.
Use kiln dried paver sand for joints. Take care when cutting. Do not over load until compaction of interlocking sand has been completed.