Paving contractors glossary
Short, plain-English definitions of the terms you'll meet when choosing a paving contractor provider in Cheltenham.
- What are edge restraints?
- Edge restraints are physical barriers (typically kerbs, edgings, or concrete haunching) installed around the perimeter of block paving to prevent the blocks from shifting and spreading outward.
- What are falls and gradients?
- Falls are the intentional slopes built into paved surfaces to direct rainwater away from structures and prevent standing water. Typical ratios range from 1:60 to 1:40 (1 mm drop per 60-40 mm of horizontal distance).
- What are flagstones?
- Flagstones are large, flat rectangular or irregular paving slabs, typically made from natural stone (such as sandstone, limestone, or slate) or reconstituted stone, used to surface patios, paths, and outdoor areas.
- What is a damp proof course (DPC)?
- A damp proof course (DPC) is a continuous layer of impermeable material built into the base of a wall to prevent ground moisture from rising into the building structure.
- What is a herringbone pattern?
- A herringbone pattern is a block paving layout where rectangular bricks are laid in alternating angled rows, creating an interlocking V-shaped design that distributes vehicle weight across the surface.
- What is a mortar bed?
- A layer of semi-dry or wet mortar applied to the sub-base that beds paving slabs in place, either as full coverage or spot applications.
- What is a riven finish?
- A riven finish is a naturally split stone surface created by cleaving along the stone's grain, producing a textured, uneven face typical of sandstone and slate paving.
- What is a sawn finish?
- A sawn finish is a flat, uniform surface created by machine-cutting stone, producing a smooth, formal appearance on paving.
- What is a sub-base?
- A compacted layer of crushed stone (typically MOT Type 1) laid directly on the ground beneath paving to distribute load and prevent subsidence or heave.
- What is a whacker plate (plate compactor)?
- A plate compactor, or whacker plate, is a machine that compresses soil, sand, or gravel by applying downward force and vibration to create a stable, level foundation for paving blocks and slabs.
- What is block paving?
- Block paving is a surface made from small interlocking concrete or clay units laid on a prepared base, typically used for driveways and patios.
- What is efflorescence?
- Efflorescence is a white powdery or crusty deposit of mineral salts that emerges on the surface of new concrete block paving as moisture evaporates.
- What is Indian sandstone?
- Indian sandstone is a naturally quarried sedimentary stone imported from India and commonly laid as outdoor paving in Britain, characterised by its warm earth tones and split surface texture.
- What is jointing compound?
- Jointing compound is a flexible resin or polymeric material applied to seal gaps between patio slabs, typically offering better durability and movement tolerance than rigid mortar pointing.
- What is kiln-dried sand?
- Kiln-dried sand is fine, heat-treated sand brushed into the joints between paving blocks to lock them together and prevent weed growth and water infiltration.
- What is MOT Type 1?
- MOT Type 1 is a graded crushed aggregate material specified as a sub-base layer in paving construction, composed of stone, dust, and recycled materials compacted to form a stable foundation.
- What is permeable paving?
- Permeable paving is a surface material with joints or a porous structure that allows rainwater to drain through to the ground below instead of creating runoff.
- What is planning permission for driveways?
- Planning permission is required in the UK when installing or replacing an impermeable driveway surface larger than 5 square metres, unless specific permitted development exemptions apply.
- What is porcelain paving?
- A man-made ceramic tile fired at high temperature, denser and less porous than natural stone, used for outdoor paving with superior durability and slip resistance.
- What is resin bonded surfacing?
- Resin bonded surfacing is a decorative paving finish where loose aggregate is scattered over a wet resin binder that hardens to lock the stones in place, creating a textured and permeable surface.
- What is resin bound surfacing?
- Resin bound surfacing is a porous paving material created by mixing decorative aggregate with clear liquid resin, troweled to a smooth finish, and left to cure as a unified surface layer.
- What is SuDS (Sustainable drainage systems)?
- SuDS (Sustainable Drainage Systems) are planning-led methods for managing surface water runoff from paved surfaces, designed to reduce flooding and water pollution while allowing natural infiltration where possible.
- What is tarmac (asphalt)?
- Tarmac (asphalt) is a bound surfacing material made from bitumen and mineral aggregates, laid hot and compacted to form a durable wearing course.
- What is the dot and dab method?
- Dot and dab is a slab-laying technique where mortar is applied only at five points (four corners and center) rather than across the entire base, making it quicker but less structurally sound than full bedding.