Key points before you start

• Get professional advice if you are in any doubt, particularly with walls over 1.5m high and complex or stress carrying structures.
• Plan the wall and draw a design; this helps with calculating quantities and makes building quicker.
• Get the right tools; spade, concrete mixer, trowel, spirit level, club hammer, 60-120mm bolster chisel, stringline and pointing tool.

A firm foundation is essential

• Walls need a concrete foundation three times wider than the thickness of the wall. Its depth should be at least 100mm with the base 300mm below ground level.
• For walls over 1m high the foundation base depth should be one third of the height of the wall above ground.

Construction

• Single skin walls 100mm thick should not be higher than 1m and need 215mm square piers every 2m.
• Walls over one metre high should be double skin construction, with the two skins tied together and should have support pillars at least every 3m.
• All walls need provision for expansion and contraction about every 6m.
• Protect the top of the wall with copings and pier caps or suitably sized paving slabs.

Bricklaying, Mortar & Joints

• Use normal bricklaying techniques including damp proof courses where appropriate.
• Mortar should be 1 part masonry cement to 4 parts soft bricklayers sand.
• Mix bricks/blocks from different packs to ensure a blend of shades. If using just one pack, select from the top down.
• With raised planters and retaining walls, leave some vertical joints un-mortared for drainage.
• Raised pools require a waterproof liner and a design that will support the weight of water.