How to lay paving slabs


Paving Installation

  • This is heavy work, requiring specific skills, tools and experience.
  • Before starting, refer to suitable professional advice, publications or websites.
  • The following advice assumes you have acquired a basic knowledge of what is required, including health and safety precautions.


  • These depend on ground conditions and expected use.
  • For light pedestrian use on solid, even ground, 40mm compacted sharp sand may be adequate.
  • For less stable or wet ground, provide 100mm well compacted hardcore beneath the sand.
  • For domestic driveways, increase the hardcore depth to 150mm. For Paviors then follow the Pavior Laying Guide; for Flagstones the section headed Driveways.


  • Mark out the area and dig out to the required total depth.
  • Tap in wooden pegs to show the levels for the finished surface, including the required gradients.
  • Infill the appropriate foundations and remove the pegs before laying the paving.
  • For Rio Paving and all Paviors, follow Pavior Laying Guide.
  • For all other paving (including Rio if preferred), follow Paving Flag Laying Guide.

Paving Flag Laying Guide

Getting Ready

  • Avoid rubbing and damage to Flags by carefully stacking them on timber battens with spacers between them.
  • Select paving from different packs throughout the job, to blend colour shades.


  • Make up a slightly wet mortar mix of 1 part cement to 5 parts building sand.
  • A PVA, SBR or equivalent bonding agent can be added to the mortar to assist bonding, particularly with natural stones. Alternatively coat the back of each flag with neat wet cement and bonding additive just before laying.
  • Prepare a full bed of mortar ahead of each Flag, approximately 25mm thick, but allowing for the variation in thickness between Flags.
  • Tap the Flag down to the required level, keeping a piece of softwood between hammer and slab.
  • If the Flag will not level with several gentle taps, lift it, adjust the level of the mortar bed and relay the Flag.
  • Draw mortar up to the sides of each Flag before laying adjacent to it. This minimises pointing later on.
  • Keep checking levels and gradient across a number of slabs. Stringlines can be helpful to define levels and lines within the laying pattern.
  • Maintain the correct joint width by gently shuffling with a trowel. Small pieces of timber are useful as temporary spacers.
  • If you need to cut Flags, a power tool with a suitable diamond tipped cutting disc will cut accurately through our products.

After Laying

  • Do not walk on the paving for at least 24 hours.
  • During wet or frosty weather, cover the paving for protection until mortar has cured.
  • Then point as soon as possible.


  • Use a damp mortar mix of 1 part cement to 4 parts building sand.
  • Press firmly onto the joints to produce a dense, impervious surface that will drain water across the paving.
  • If mortar gets onto the faces of the Flags, clean off immediately using a damp sponge frequently rinsed in clean water.
  • Jointing sands and other pervious materials are not recommended except where paving is laid with minimal joints.
  • Where minimal joints are recommended, these should be 2-3mm and filled with a kiln dried jointing sand. Butt jointing is not recommended for any of our products.
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