Most garden walls are built with modern lightweight Celcon or Toplite blocks. These arc-cheaper than bricks and have superseded breeze blocks, which are made from highly expensive, imported blown volcanic clay. Heavier and sturdier walls can be achieved with the use of ‘concrete’ blocks. These are, however, more difficult to cut and transport around the garden. If you’re building a smaller wall, use ordinary bricks, which can be laid in small spaces, and won’t need to be cut. Brick prices rise steeply with the better-made and designed display bricks.
Use pegs and a builder’s line to mark out the position of the ‘face’ of the wall (the side of the wall that will be most visible); this should follow a straight line, unless there is a designed curve (see below right).
It’s now time to start bricklaying. You can mix your mortar from one part cement to six parts soft sand, or buy a ready-made mix from a large DIY store. Work one wheelbarrow load at a time and, if the weather is hot, cover the mix with a sheet of plastic or wood to stop the mortar from drying out too quickly.
Begin by trowelling a 1cm (1/2 in) layer of mortar on to the footing. Then, using your line as a guide, and checking every so often with a spirit level, start bedding in the first course of bricks.
If the first brick is to butt up to an existing wall, then its ends will need to be ‘buttered’. To do this, hold the brick in one hand, trowel on a small amount of mortar, and then roughly shape it so that the mortar is at its thickest in the middle, sloping off to both sides. Then lay the brick lengthways, with the buttered end touching the bricks of the wall. Tamp the brick down on to the mortar bed and check that the brick is lined up with a spirit level in 90 directions.
Lay brick after brick, course after course then, after about six courses, step back and start cleaning up the mortar, which should be stiff enough to work. First use a jointing iron, or the bend in a piece of 1cm (1/2 in) copper pipe, to smooth a nice clean finish between each course, then brush off the small blobs of semi-dry mortar with a soft hand brush.
To protect your garden, you need garden walls but that is only possible if you know how to construct garden walls. Otherwise you can pay to a professional to carry out this task. You can also learn how to build a raised border in your mini-garden.