Laying Block Paving

Planning

• It is important to check the suitability of your intended foundations with a professional, based on your requirements e.g. traffic type and your site's ground conditions.
• For most domestic applications, it is usually sufficient to dig out 260 mm below the block paving surface, assuming a block depth of 60mm, a screeding layer of 50mm and sub-base of 150mm.
• Ensure the surface of the block paving is at least 150mm below the damp proof course in any adjacent wall. You will need to plan for a fall of at least 1:40 towards suitable drainage.

Groundwork

• Mark out the area and dig out to the required depth, making sure you dig out any soft spots and backfill with well compacted subbase.
• Tap in wooden pegs to show the levels for the finished surface, including the required gradients.
• Install all required drainage materials.
• Infill the foundations to the required depth for the subbase. A well compacted MOT Type 1 usually gives good results.

Edge Restraints

• Block paving must be surrounded by a firm edge restraint to prevent movement of the blocks during use and loss of the sand layer.
• Kerbs, walling, decorative edging, or even the block paving can be used. These must be laid on a concrete bed and haunched in the concrete, then allowed to cure and strengthen prior to any vibration.

Screeding

• Screed out a layer of coarse concreting sand, to a depth of 65mm, within the edged area and compact with a plate vibrator to a depth of 50mm. More sand may need to be added. (1 tonne of sand usually covers 8m2 to achieve this thickness.)

Laying

• It is important to not only draw simultaneously from at least three packs, but to also draw down vertically from each pack, rather than layer by layer. This will give the best colour blend and overal result, as colour variations will occur, even in single colour blocks.
• Start laying from a corner or long edge and proceed along the laying face, according to the pattern.
• Use stringlines and adjust the widths of the joints to within 2-5mm, to ensure the lines in the pattern remain straight. Remember to avoid straight joints running across courses, when following a staggered bond pattern.
• To fill gaps along the edge, cut blocks using either hammer and bolster, mechanical block splitter, or power cutter, adheering to all relevant safety advice. Avoid using blocks less than a quarter of their original size.

Vibrating

• Brush bedding sand into the joints to partially fill them and to provide stability for the initial vibration.
• Ensure the surface of the block paving is clean and vibrate the paving to settle the sand in the joints.
• Top up the joints with kiln dried sand, sweep the surface and pass the vibrator over the whole area, several times, to level the area. Brush more kiln dried sand into the joints and vibrate for the final time. After a final sweep the paving is ready for use.