The following notes are intended to be sufficient to enable you to tackle simple garden-wall type projects. For your first attempt at laying bricks, it is a good idea either to build your wall dry, or make up a mix of soft sand and water so that you can practise spreading mortar.
The mortar and bricks
Real mortar should never turn out too hard when set, in fact never harder than the bricks it bonds. One part cement to five of clean soft sand, plus a plasticiser is a good average mix. The plasticiser makes the mortar ‘buttery’ and easier to handle and adds extra adhesion. Never make the mix too sloppy or you’ll have problems handling it and it will be squeezed out by the weight of the bricks and mark your brickwork.
Mortar has a limited life; one and a half to two hours is about the limit, and once it stiffens should never be ‘knocked up’ again with water. When it starts to stiffen throw it away. There are all kinds of brick, but for most projects medium density facing bricks will do. Avoid really soft bricks which soon break down if exposed to the elements. Bricks for foundation work which is to be hidden away could be common bricks, but choose sound ones.
Choose your bond
If you look at any brickwork you will see that the vertical joints are staggered so that no two line up. The simplest bond is the stretcher bond, and using standard bricks 22.5 cm x 11.25 cm x 7.5 cm (allowing 1 cm joints) to produce a wall, you produce a wall 11.25 cm thick. The size given includes a thickness of mortar, so the brick is in fact slightly smaller than quoted. A wall produced in this bond would not be very strong, so if it is more than about 38 cm high, pillars need to be built into the wall to add support. These will be 22.50 cm by 22.50 cm and the addition of pillars will involve the cutting of half-bricks (referred to as ‘queen closers’).
If you turn a corner in this bond, rather than build a pillar it is probably better to just interlocks as illustrated. Where a stronger wall is required you can build a double thickness wall (22.50 cm), and this needs no strengthening. You can also use more decorative bonds (i.e. English or Flemishbonds) than for a half brick wall. These involve the stretcher bond already mentioned plus headers (bricks laid across the width of the wall). English garden wall bond is really a modification of another bond and it consists of one course of headers to three of stretchers. It produces an interesting and fairly economical wall. With this bond you will note that a piece about 5.6 cm wide (called a queen closer) has to be placed next to the corner header bricks.
Bricks are cut using a wide blade chisel called a bolster, and the bolster is tapped firmly with a club hammer. Grooves are nicked in both sides of the brick, then a good sharp tap will split the brick along the cuts. Having said that, practise for a while with old bricks until you get the knack.
The most important part of any wall is its foundation, and if this is out of true, you will have a hard job producing a wall. Always cut your foundations horizontal, on sloping ground this may involve stepping them to accommodate the slope, make each step equivalent to a whole number of bricks plus mortar. And the foundation must be strong enough to bear the weight of the wall. For a light garden wall, 30 cm deep should be sufficient if the soil is firm and well drained. But on unstable or weak ground, make the depth 46 cm. Make the trench twice the width of the brickwork. Lay a concrete footing of, say, 1 cement, 6 ballest to a depth of about 15cm (6 inch) in the bottom of the trench. (See our page giving details for foundations for more details)
Laying the bricks
When you come to actual laying, you will note that your bricks have an indent on one face, called a ‘frog’. The brick should be laid with the frog up, this will ensure that the frog is then filled with mortar as work progresses and no voids are left within the wall.
With your foundations laid, mix enough mortar for an hour and stack bricks near the job. Place some mortar on your mortar board and you are ready to start. Lay a course of bricks dry first to see the work fits in the given space. Open or close joints slightly if necessary rather than have to cut bricks. Start with a corner brick and bed it in mortar, run a line from the laid brick to the opposite corner of the wall. Lay a second brick a metre or so along the line then checked with the spirit level. Then fill in between bricks. Proceed in this way until the far corner or end is reached. The first course must be straight and true!
When you’ve laid a number of bricks, you need to check and adjust them. The four checks are (in order):
- Gauge – use the gauge rod to make sure that the corner brick is the correct height.
- Level – use the spirit level to check that the row of bricks is horizontal. Don’t try tolevel each individual brick.
- Plumb – Use the spirit level to make sure the wall is vertical.
- Straight – use a straight edge horizontally along the face of the wall and adjust so that they are all in line.
(for further details of these checks, see further pages)
When you first start bricklaying, you may want to check and adjust and then check it all again. After a little experience, you’ll be quite confident to just check and adjust once. Bricks are mass produced and are not perfectly square, so you won’t get a perfect level along the top of the bricks or a straight line along the face. Now building up the corners, checking each course (Gauge, Level, Plumb and Straight). With the corners built, you can fill in the rest of the wall using a line between the corners. The actual joints may look a little ragged, so as the mortar stiffens, strike the joints as required.