Marshalls is a world leading paving manufacturer that’s not only big on quality paving, but also on expert installation. They provide installation guidelines for all their paving products, which comply with the British Standard BS7533 dedicated to paving.
It is crucial that your driveway is installed to British Standards for legal reasons. For example, SUDs legislation states that any rainfall that falls onto your property should be drained on your property and does not flow onto the road. Now if you had your driveway installed by a landscaping company and they didn’t install adequate drainage, you would be held responsible – not the landscaping company.
To make sure you aren’t putting yourself at risk, check these guidelines against what you have been quoted:
- Excavation & sub-base – For most driveways, a 250mm dig out is required followed by a sub-base of 160-180mm compacted into layers – should be sufficient
- Material Selection – Granular sub-base material should be well graded (40mm to dust) Type 1 quality material. Recycled materials such as crushed masonry or concrete can be considered, provided it is well graded to British standard and compacts to give a close textured finish. Materials containing organic matter should not be used.
- Construction – Sub-base material should be placed in layers not exceeding 75mm in thickness. Each layer should be fully compacted before the next layer is placed. Sub-base tolerance to be +5 -10mm from specified levels. The surface should be clean and suitably close textured to prevent migration of finer material through the construction.
- It’s extremely important to remember that the finished surface level of the blocks must be a minimum of 150mm below the DPC (damp proof course) to prevent problems with rising damp.
- Edge Restraints – Edge restraints should be placed around the perimeter where the paving is not finished against the wall. The restraints should span the depth of the dig out to stop any lateral movement.
- Laying Course – The paving should be laid on 30-40mm of coarse sand which has been screeded off to falls and levels.
- Joints – All joints should be fully filled with kiln dried sand and excess removed.
- Cutting – Cutting may be carried out using a diamond tipped power saw, a block-splitting guillotine, or hammer and bolster. It must however be noted that the aesthetic finish achieved will depend greatly upon the choice of cutting mechanism and level of skill. Specific equipment or blade types should be used when cutting natural stone units as those designed for cutting concrete pavers may blunt easily. Cut edges on cropped setts will need distressing prior to installation. Cut blocks should be inserted prior to completion of the working period or before the onset of inclement weather.
- Inclement Weather – In adverse weather conditions, units should not be laid on saturated laying course material. The filling of joints is not possible in damp conditions and should be topped up at the earliest opportunity.
Received quotes but you’re not sure which company to hire? Click here to download our FREE Landscaper Checklist. It details everything you should check before accepting a quote.
If you have any questions, please don’t hesitate to contact us or visit www.marshalls.co.uk/homeowners