How to Lay a Brick Wall

Plan, count and set out

Before you order materials, sketch the wall to scale on a piece of paper — including any returns, pillars or opening for a gate. Count the bricks by working out the square metres of wall face and multiplying by 60 (the standard coverage for a UK metric brick at 10mm joints). Add 10% for cuts, breakages and the inevitable "I dropped one". Order cement, soft sand, DPC and at least 2 bags of post-mix if your foundations are deeper than 600mm.

Mark the wall line with string lines and pins, checking corners with the 3-4-5 method. Drive the corner pegs in at finished course height so the string line doubles as a level reference. Spray the foundation trench outline onto the grass with marker paint before you dig.

Tip: Lay out a dry course (no mortar) of bricks along the trench line first, with 10mm spacers between them. This stops you running out of bricks mid-foundation and gives you an instant gauge for any cuts at the ends.

Pour the foundation

The same rule applies to a brick wall as to a block wall: a strip foundation twice the wall width, 225–300mm deep for a non-load-bearing garden wall. Mix a 1:5 cement-to-all-in-ballast footing mix (or use post-mix / foundation concrete from a bag) and pour to ground level. Tamp level with a piece of timber, leave it proud by a course or two, and let it cure for at least 24 hours before you start laying — 48 if the weather is cold.

Bed a strip of DPC into the mortar joint of the first course, at least 150mm above finished ground level. The DPC should run continuously across the wall, with 100mm laps at corners and returns. Without a DPC the wall will wick moisture and stain within a season.

Mix the mortar

For brickwork above ground, use a 1:4 mix by volume — one part Portland cement to four parts soft sand. Add a plasticiser to make the mortar more workable (it spreads further, trowels easier, and gives a better bond). If you'd rather skip the measuring, bagged quality-assured mortar gives a consistent mix every time.

Mix only what you can use in an hour — mortar stiffens quickly in warm weather and starts to lose workability after about 90 minutes. The mix should hold its shape on the trowel without slumping. Too wet, and you'll get shrinkage cracks as it dries; too dry, and it won't bond to the bricks.

Common beginner mistake: adding too much water to "make it spread easier". It spreads, but it loses strength. Add water gradually until the mix just holds its shape when you squeeze a handful.

Lay the first course

The first course sets every other line, plumb and level on the wall. Bed the corner bricks first onto a full mortar bed about 10mm thick. Tap each one level across both axes with a rubber mallet. Run a string line taut between the corners to align the rest of the course, then lay each brick into a fresh mortar bed, leaving a 10mm perpend joint between each.

Check the whole first course with a long spirit level before you bed the second. If any one brick is proud, lift it and re-bed; if it's low, lift and shim it with more mortar. A flat first course pays for itself in the next twenty.

Build up in stretcher bond

From the second course up, every brick should be centred over the perpend joint in the course below — that's a stretcher bond, and it's the strongest pattern for a single-skin wall. Cut half-bricks at every other course end using a bolster and lump hammer, or hire a block splitter for longer runs. Aim to use the offcuts as half-bricks in the next course rather than wasting them.

A useful rule for an accurate wall: check level, line and plumb on every brick. Press mortar firmly onto the bed face and one perpend of each brick before laying — a full bed is much stronger than a stripped one and stops cold joints.

If you're building a cavity wall or anything structural, follow the engineer's spec for wall-tie spacing, bed-joint reinforcement and pier positions. The most common DIY mistake on a structural wall is ignoring the engineer's notes.

Point the joints

Once the mortar has thumb-dry (firms up under light thumb pressure but doesn't smudge), point the joints with a jointing iron or a piece of 12mm garden hose for a rounded, weather-resistant finish. Brush the wall down with a soft brush once the pointing has firmed but before the mortar is fully hard — that flicks off smear and brings the sand to the surface for a clean, textured finish.

Materials and tools checklist

Materials

• Facing bricks — order 10% over your count for cuts and breakages
• Soft sand — for the mortar
• Portland cement — or a quality-assured bagged mortar
• DPC strip — 100mm wider than the wall
• Plasticiser — improves workability
• Coping stones — to cap the top course

Tools

• Wheelbarrow and spade
• Brick trowel
• Rubber mallet
• Long spirit level (1.2m or longer)
• Builder's line and pins
• Bolster and lump hammer (or block splitter hire)
• Jointing iron
• Soft brush

When to call a bricklayer

A 1m × 3m single-skin garden wall is a fine DIY weekend for two people with some building experience. Get a quote from a local bricklayer if:

• The wall is over 1m tall or anywhere near a highway
• It's structural (part of a building, retaining or load-bearing)
• The wall has returns, openings or piers — corners slow beginners down
• You want it to match an existing wall or a particular bond pattern

Either way, we've got the bricks, sand, cement and DPC at trade prices and deliver next-day across Berkshire, Buckinghamshire, Surrey and the wider South East.