Prior to laying
One of the primary things to do before attempting a patio, is to decide on a particular pattern. A pattern can basically be one of two types.
- Regular – symmetry in at least one direction.
- Random – slabs laid randomly i.e. joints together, but no symmetry. When designing a random pattern, it is usually preferable to avoid laying cross-joints (i.e. where four corners meet).
Once you have settled on a pattern type, you should design it on squared-paper if it is not one that you have a pre-printed design for already. You can print out a blank design template from our Patterns Page.
Paving Slab Preparation
It is often a good idea to “dry lay” some or all of your paving slabs before attempting to lay them permanently. Laying paving slabs dry, means that you place the slabs onto the ground “as is” in the pattern you propose. This will allow you to determine if and where any cutting or adjustment will be required. If the whole area is to be paved, then it is usually common practice to begin laying at one corner and work in a fan towards an opposite corner. If you wish to lay only a part of the main area, then the dry-lay will be even more important. This is especially true for a rotary paving product, which will go to makeup a circle. This type of product so often ends up as a separate feature, away from other landmarks and guides. Then you will be able to mark the area, cut out turf if necessary, and adjust joint widths.
Laying Paving Slabs
Remove vegetation and topsoil, compact and level the area and if necessary build-up with hardcore or scalpings to required levels. When laying paving adjacent to the walls of a building, ensure that the top surface is at least 150mm (6″) below the level of the damp-proof course. Set out the area with string lines and level pegs. The paving should slope away from the walls with a fall of at least 25mm in every 1.5m (1″ in every 5′).
This is the simplest and most cost-effective method suitable for casual foot traffic only. A bed of sharp washed sand is spread evenly over the area to a depth of at least 25mm (1″) and the paving pressed into this. Sand or fine soil may be brushed into the joints upon completion. Some movement or settlement of the paving can be expected with this method. 40kg sand for bedding of slabs will cover approximately 1 Sq Metre (1.2 Sq Yards) giving a 25mm (1″) bed.
Use a mix of one part ordinary Portland cement to six parts of sharp washed sand. “Spot bedding”, i.e. a small mound of mortar under each corner and also one in the middle on larger slabs makes for easy adjustment of levels. A full “Mortar Bed” will provide the best and most permanent support for your paving but makes it more difficult to get the slabs true to level without repeated lifting. The slabs should be placed in position and levelled by lightly tapping with a hammer and a block of wood. The slab should not rock in any direction. Check for accuracy with a straightedge in both directions using the pegs for reference. Repeat with successive slabs using small pieces of batten 10mm (3/8″) thick as spacers for your joints. Check the alignment and level against adjoining slabs with a straightedge spanning two or more slabs. Joints between slabs can be filled with 4:1 mortar mix (four parts building sand to one part cement) well rammed in with a piece of wood. Be sure to use a dry, stiff mix to avoid staining the surface of the paving. Clean any excess from the slab face with a damp sponge.
None should be required other than the occasional cleaning with water and a stiff brush if so required. Careful use of a pressure washer might also be considered. No chemicals of any kind should be used.