How to Build a Brick Wall

Bricklaying is skilled work that can take many years to master. However, in this article, we aim to show you how to build a simple low wall of less than 1 metre in height.

Walls can be built in several widths; a single course of bricks is known as a half brick and is only suitable to a height of around 45 cm. Anything higher should be built from either a parallel pair of half brick walls or a full brick width wall - one that includes headers so the length of the brick comprises the thickness of the wall.

Walls must be finished with a brick and a half pier at each end if it is retains even a small amount of soil, and any wall longer than 3 m must have intermediate piers.

1. Create the Footings

Mark out the site using two lines and pegs to ensure it is square. Dig the foundation trench the length of your wall including any piers at each end. Make it at least 38 cm deep for half thickness wall, and 43 cm for a double thickness wall. The trench should be at least 20 cm wider than the wall itself (10 cm on each side).

Check that the trench is level and the sides are vertical. Knock two pegs into the ground to the level of the concrete, bearing in mind that the top of the final footing should be at least 15 cm below ground level to give adequate frost cover.

Add a 13 cm layer of hardcore, and tamp this down. Pour in a 10 cm layer of concrete (15 cm for a double thickness wall) and chop through this with your shovel to dispel air and work it in.

Leave to harden for a few days before you start building.

2. Lay the First Course of Bricks

To ensure that the first course is straight, put timber profile boards at each end of your trench and stretch two parallel strings along the footing, the space between them equal to the width of the wall.

If your wall is to be finished with a pier at each end, start by building these by placing two bricks side by side for a half brick thickness wall, and by laying four bricks at 90 degrees to each other for a full thickness wall.

If the bricks you are using have a 'frog' (an indentation on one side), you must always ensure that it is laid uppermost. This ensures that there are no voids within the brickwork that could become weak spots and also that the loading of the wall is spread evenly across its width, rather than being concentrated onto the edges.

Lay a 1 cm bed of masonry mortar along the footing, and lay the first brick unmortared into this. Butter one end of the next brick and lay it up against the first, squeezing the mortar to a width of 1 cm. As you lay, check frequently with a spirit level that the bricks are level and horizontal; tap them down with the heel of the trowel if necessary. Insert more mortar under any that are too low. Any excess mortar extruded from the joints should be scraped off with the trowel, and then the process repeated with the next brick.

3. Finishing the Joints

After laying a course of bricks, finish the joints before the mortar dries. Use a smaller pointing trowel to give a neat, bevelled finish. Vertical joints should all be bevelled in the same direction, whilst horizontal joints should slope slightly downwards to help water run-off.

4. Continuing the Courses

As the first course is completed, move the guide line up to the next course. The second course is then buttered with mortar and laid with the joints staggered in a running or stretcher bond.

Repeat the process for subsequent courses.

4. Adding Weep Holes

For retaining walls, leave weep holes (un-mortared gaps between bricks) for drainage in the first course that is completely above ground level.

5. Installing the Damp-Proof Course

A Damp-Proof Course (DPC) can be included at 15 cm (two courses) above ground level. This is a layer of impermeable material built into the wall to prevent ground water travelling upwards through the brickwork. The easiest DPC to install is a polymer sheet, and is simply rolled out on top of the second course above ground level, making sure that any joins overlap by at least 4 cm.

Once in position, you will continue laying the bricks as normal, covering the DPC with a bed of mortar and then laying the next course of bricks above it.

Whilst all freestanding walls may not need a DPC, it costs very little to include and will guarantee a longer life for the wall.

Engineering bricks may also be used to create a DPC as their very low water absorption capability prevents the upward migration of groundwater. Two courses of engineering bricks will need to be laid to provide adequate protection.

6. Completing the Wall

Carry on laying courses of bricks, cutting them where necessary, until you have reached the required height. The project may take several days work to complete, so ensure that you cover any unfinished brickwork and the bricks themselves to prevent them from becoming damp or wet.

Add a finishing top or coping to your wall, either using special capping or coping bricks to match your wall bricks, engineering bricks, concrete cast coping slabs, or narrow slabs which match your paving. Coping is not only decorative, but prevents frost damage by shedding rainwater.