Ketley Square Edged Pavers for Rigid Construction

Rigid fixing of pavers is the traditional method of laying and offers benefits in certain applications. The mortar joint can be used to complement or contrast adjacent brickwork. The joints can be used as a feature by the use of coloured mortars, it can also provide structural ' strength in areas subject to high volumes of water or frequent high pressure water hosing.

Base Requirements

Generally the base for rigid paving will be concrete, either plain or reinforced. The composition and thickness is dependent on structural design considerations but typically will be 100-150mm thick with a compressive grade up to C20P depending on the structural design considerations.

Pavers

There is no British Standard covering the rigid type of pavement or the clay pavers for use in them. Durability tends to be the main choice criterion, and reference should be made to BSEN 771-1 - Compliance with "F2".

Mortars

When pavers are fixed rigidly the mortars used for jointing and bedding must have a sufficiently low permeability and adequate cement content to ensure good frost resistance. In general only 1 : 3 cement : sand mix or 1 : 1/4 : 3 cement : lime : sand should be used. The constituents and preparation of the mortar should be in accordance with the recommendations of BS5628: Part 1: 2005 (The Code of Practice for brickwork). it is recommended that a tooled, slightly dished joint profile referred to as "bucket handle" is specified. This method helps to seal the surface of the joints and presses the mortar against the pavers.

Movement Joints

When pavers are laid in the rigid format it is essential to provide adequate movement joints Perimeter joints should be provided around rigid paved areas if any dimension of the paved area exceeds 6 metres, and thereafter at approximately 6 metre intervals. In addition movement joints should be provided around fixed points of restraint such as manhole cover columns and upstands. Where there is a movement joint in the concrete base this should be carried through to the surface. Movement joints are usually 10mm wide and should comprise of a compressible joint filler, such as polyethylene foam, a barrier (or joint breaker) and an extensible tack free sealant.

Cleaning

During construction great care must be taken to avoid cement staining of the paver faces. Any cement or lime stains may be removed by the careful use of proprietary brickwork cleaners which are based on dilute hydrochloric acid solution. These should be used in accordance with the manufacturers health and safety recommendations. It is important to saturate the surface with clean water before applying cleaning agents. A rigid pavement does not become fully mature for approximately 28 days after laying. Therefore it is recommended that trafficking must be delayed until after that time. For external paving sweeping is the only "routine" maintenance required but in damp and shaded areas a suitable weedkiller may be required to treat moss and algae growth. internal paving can be cleaned using a mild detergent and warm water.