ARTICLE

How to build a garden wall

First things first. If you're going to build a garden wall it has to be safe and it has to be legal. In this article we look at the basics of building a low garden wall. One caveat before we begin - building brick walls is hard work. Hard but satisfying! So, here's how to build a wall!

How to build a garden wall

How to build a garden wall

WHAT DO I NEED?

  • Profile boards and line
  • Trowel
  • Sharp sand
  • Cement and ballast or ready-mixed concrete
  • Bricks
  • Bucket
  • Shovel
  • Plastic sheeting
  • Spirit level
  • Plumb line
  • Hammer and bolster chisel
  • Bricklayer’s line and pegs
  • Stiff hand brush


  • Do I need planning permission?
  • How many bricks will I need?
  • What about the foundations?
  • And how do I lay the concrete footing?
  • How do I go about laying the first course of bricks?
  • How do I cut bricks?
  • Building up the end piers of the wall
  • When do I start filling in between the piers?
  • What is pointing?

    Time to complete job: A couple of weekends for a small wall.
    Approximate budget: From £.60 per brick.


    Do I need planning permission?
    If you’re planning a wall next to a highway or footpath, one metre is the maximum permissible height without planning permission. Two metres is the maximum height when building elsewhere. For more details see the Government's Planning Portal.
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    How many bricks will I need?
    That depends on how many ‘courses’ (rows) and also how the bricks will be laid, either as ‘headers’ (bricks laid with their short side facing out) or ‘stretchers’ (bricks laid with their long side facing out).

    This wall is a simple stretcher bond, the bricks laid end-to-end, and each course overlapping the one below by half a brick.

    We are building end piers, too. These are square pillars at each end, the dimensions of which are two whole bricks side-by-side. As a guide, this wall will require 60 bricks per square metre, plus an additional 14 bricks/metre height of the piers at each end.
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    What about the foundations?
    The stronger the foundations, the stronger your wall so take your time to get this stage right. The height and width of your wall will determine the depth of the foundations. A single skin wall up to 1m (3’3”) high needs a footing at least 150mm (6”) deep and 300mm (12”) wide.

    An extra 100mm (4”) is needed if your soil is clay because the ground can swell. If the subsoil is loose dig a little further and lay compacted hardcore to create a base. For walls only three or four courses high, a shallower footing or pre-prepared concrete bricks are fine.
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    And how do I lay the concrete footing?
    To do this mark out the area of the wall on the ground with string attached to pegs and dig the trench directly underneath the string. Keep an eye out for drains and remove any tree roots you encounter.

    Now mix your concrete, one part cement to five parts ballast (sand and gravel) adding water to create a thick, pouring consistency of concrete. Alternatively, use ready-mixed bags. Pour the concrete into the trench to the correct height, and leave to dry for a few days.

    Tip: Always wear protective mask, goggles and gloves
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    How do I go about laying the first course of bricks?
    The key thing is ensuring that the first layer is absolutely level. If it isn’t, the wall will be unstable. The process goes like this:

    1) At either end of the footing, fix profile boards (two pegs hammered into the ground with a horizontal batten fixed at about two brick courses high between the two). Now pull two strings taut from one profile board to another, a brick width apart, describing the two sides of the first course of bricks.

    2) Lay the bricks in place without mortar to check their positioning. To create an end, or as it is called, 'pier', start the first course by laying the first brick at right angles to the course (a header), with one of its ends flush with one face of the wall. The end pier is a square section (two bricks laid lengthways side by side) with the main wall flush with one side of this pier. You will need to cut a half brick to lay in the angle between main wall and pier header on the first course, to create the square section. See our next section for how to cut bricks.

    3) With a brick trowel place a dollop of mortar at one end of the footing for the pier, and a layer of mortar 10mm (3/8") to lay the first five bricks. Make sure any ‘frog’ (the hollow indentation in a brick) is facing upwards.

    4) Keep checking with a spirit level and the strings of the profile boards that the bricks are level and straight as you work along the course. When butting one brick to another, 'butter' the end of the brick you are laying with mortar, to bond to the previously laid brick.

    5) Continue laying your first course of bricks, scraping away excess mortar.

    6) When the first course is complete, straight and perfectly level, (with a pier at the other end, too) remove your string and profile boards.

    Tip: Practise bricklaying with a 1:1.5 sand-lime mortar mix that breaks apart when dry
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    How do I cut bricks?
    Place the brick on a hard surface and use a club hammer and bolster to create a shallow groove all the way around the brick, half way along its length. Hit the bolster, held at right angles to the brick side, with hard blows from the hammer to create the groove.

    With a groove cut all the way around, then place the bolster blade in one of the grooves, and hit the bolster with the hammer until the brick breaks in two, hopefully following the grooves you've already cut.

    Tip: Keep your wall low until you know what you’re doing
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    Building up the end piers of the wall
    You need to ‘rack’ the wall ends by building up the retaining piers at either end. Effectively, you are building a half pyramid at each end, with one brick on the top layer, two on the next, and so on down. If you do this at each end, you will have a series of stepped bricks, working from the first course laid, with each course finishing half a brick shorter than the one underneath.

    You don’t fill in the bricks between the piers at this stage, you’re simply creating the steps that lead to the top of the pier. So here's the process:
  • Build up the pier at the ends of the wall by three courses, alternating the bricks in this formation: header-stretcher-header, with a half brick in the angle between the pier and wall every second course.
  • To check your bricks and mortar are evenly spaced vertically, you’ll need to use a gauge rod. Either buy one, or make one with a long batten and mark indentations with brick and mortar heights for each course.
  • Keep checking with your spirit level that the pier is both horizontal and level and also that the emerging gradient of steps is even - do this by laying your level down the slope of the stepped bricks... the level should touch each brick edge.

    Tip: Give yourself plenty of time. Whatever you do, don’t rush it!
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    When do I start filling in between the piers?
    When each pier is five or so bricks high, it's time to lay the courses between them.
  • Set a bricklayer’s line (a taut line secured in place with steel pins inserted into the mortar between courses) suspended between the piers, and set at the exact height of the course to be laid.
  • Use this line as a guide to lay the next course of bricks.
  • To lay a course, lay a bed of mortar on the previous course of bricks, and place your 'buttered' brick on this layer, tapping into place to match up with the bricklayer's line. Check every few bricks with a level to ensure they are perfectly straight and level in all directions.
  • As you start on subsequent courses move the line to the height of that course.
  • When you lay the final course of bricks lay them with the frog facing downwards.
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    What is pointing?
    Pointing is filling in any missing areas of mortar between bricks, and enhancing its appearance with neat, uniform joints and making it weatherproof. The key thing with pointing is that the mortar is the right consistency to work with so leave the bricks about an hour before doing the pointing. If your wall is very long it’s best to point in stages so the mortar doesn’t get too firm.

    You can achieve different effects by using the edge of a pointing trowel, or a rounded blade, like a bent length of copper piping. Rub your tool along the mortar joint, creating a downwards slope with the trowel, or a rounded profile with the pipe. If pointing with a slope, make sure all the vertical joints slope the same way. After pointing, use a stiff brush to remove any excess mortar before it dries fully. Craig Phillips has this excellent advice on repointing, which will help you get the right idea.
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