5.10 Materials guidance

Paving materials should be easy to maintain and replace, durable and of an attractive appearance that is appropriate to the local character.

A simple palette, with a limited number of materials and colours is preferable. Using too many paving types can result in a visually messy and incoherent environment that will be hard to maintain and repair.

Consideration must be given to the whole life costs of materials when deciding which to be used.

Paved surfaces for most new schemes will be of flexible construction. The following materials should be used:

Carriageways on Primary streets, Secondary streets, High streets (trafficked), Local streets, Lanes must be constructed from either:

• Hot Rolled Asphalt (HRA)
• Proprietary systems, such as thin surfacing systems
• High friction surfacing where required

Carriageways on High streets (non-trafficked), residential and commercial mews, shared surface streets should be constructed from either:

• Block paving systems (flexible construction)
• Clay pavers or bricks
• Concrete block paving

Natural stone pavements of a rigid construction can be used in certain circumstances where a very high-quality finish is required. Smaller modular units, such as setts, are less likely to break and are easier to reinstate.

Pavements must be constructed from:

Block, slab, or flag paving systems (flexible construction)

• Natural stone paving flags
• Clay pavers or bricks
• Precast concrete paving flags
• Concrete block paving

Most utilities will be routed under pavements, so paving systems must be easy to lift and reinstate without the need for specialist contractors or materials.

Cycle lanes must be constructed from either:

• Dense bituminous macadam
• Proprietary surfacing systems, such as ‘spray and chip’
• A coloured surface course can be used in limited circumstances where it is necessary to provide contrast with the footway or carriageway. General use of coloured surface courses should be avoided.
• A high quality, smooth finish must be used for rider comfort.

Raised tables must be constructed from:

Block paving systems (rigid construction for high traffic areas, flexible elsewhere)

• Clay pavers or bricks
• Concrete block paving
• Concrete block paving (permeable)

Natural stone (rigid construction) should be used where a high-quality finish is required. In some circumstances this may be more economical, as a rigid constructure is more durable and has better resistance to torsion from turning vehicles.

Ramps must be constructed from either:

• Proprietary precast concrete ramp section;
• Granite setts (rigid construction) with smooth finish;

Edgings and channels must be constructed from either:

• Granite setts;
• Natural stone;
• Clay paving;

Parking bays must be constructed from either:

Hot rolled asphalt (HRA)

Block paving systems (flexible construction)

• Clay pavers
• Concrete block paving

Permeable paving systems

• Permeable concrete block paving
• Permeable concrete
• Permeable asphalt (TBC)

While asphalt is one of the ubiquitous and affordable paving materials, it requires more maintenance and upkeep costs in the long term. It is one of the most impermeable materials, and therefore generates more surface water runoff and has a higher impact on drainage. It also contributes more to heat island effects than other materials.

The use of natural stone and clay paving materials must be encouraged and should be used wherever feasible.

Asphalt should not be used for pavements on non or very low trafficked areas.

The use of permeable paving should be encouraged but will only be adopted in certain circumstances. The most suitable location for permeable paving is in parking bays, low traffic and traffic free streets. If used in parking bays on the street, the impermeable carriageway can be designed to shed water to the parking bays, reducing the need for positive drainage, such as gullies. The main types of permeable paving that will be adopted are:

• Permeable concrete block paving (CBP);
• Permeable clay pavers;
• Permeable asphalt;
• Permeable concrete; and
• Resin bound gravel (only suitable for tree pits and off-street pathways).

Permeable paving should not be laid over any existing or proposed services wherever possible as this will avoid the need for excavating and reinstating the permeable paving if a utility provider needs to repair or replace services. Service strips and trenches can be created using non permeable paving to accommodate services. Further guidance is available in the Interpave guidance [Reference 15].

Permeable paving can be used in all sites, but the choice of sub-base system will depend on the local ground conditions. The sub-base can either allow infiltration into the ground below, be fully lined and drain to a surface water drainage system or allow both partial infiltration and be connected to the drainage system. Further guidance is provided in Chapter 8 – Sustainable drainage systems.

References

• Reference 15: Interpave (2018) Design and Construction of Concrete Block Permeable Pavements Edition 7 (Return to content for reference 15).