Walls made from concrete panels may be affordable and easy to erect, but let’s face it, they don’t hold a candle to a ‘proper’ brick wall. Here’s the thing: you can build one yourself.
Laying foot strippings
Before you get started, you need to know that a wall must be built on a firm, level footing or it will soon crack and fall down. The usual footing is a solid layer of concrete on a bed of hard earth. A low wall can be built on a flat, firm surface such as a patio, as long as it has an adequate sub-base and the slabs are set on a full bed of mortar. Set the wall back from the edge the same distance again as its thickness, but not less than 150 mm.
You will need:
Spade; profile boards; string; heavy hammer; earth rammer or stout length of timber; pencil or chalk; steel tape measure; spirit level; rake; straight-edged board; mixing platform; brick trowel.
Marker pegs; concrete; reinforcing mesh. Possibly also clean fill.
* Footing measurements
The width and depth of the footing depends on the thickness and height of the wall. Footings need to be a little deeper than recommended where the soil is clay (which shrinks and expands according to the weather), or is soft and loose-knit (such as peaty or sandy soil).
1. Mark the edge of each side of the foundation strip using string lines and profile boards. Position the boards well back from each end of the trench.
2. Remove 50-75 mm of topsoil and spread it on other parts of the garden.
3. Measure from the top of each marker peg and mark lines showing the top of the concrete, which, unless you are using clean filling, will be at the bottom of the trench.
4. Drive in the marker pegs on each side of the strip at about 1 m intervals, with their tops at the required height for the surface of the concrete. Generally, the concrete is laid so that it is level with a hard surrounding surface, or 25-50 mm below a lawn edge.
5. Level adjacent and opposite pegs using a spirit level, set on a length of board if necessary.
6. Dig a trench as wide as the marked lines and to the required overall depth, using the bottom line on the marker pegs as a guide. If the soil is still soft, dig a little deeper.
7. For heavy structures such as houses and retaining walls, the soil strength (bearing) must be equally firm all over. If in doubt, consult your council building surveyor. You might be instructed to call in an engineer to detail a special footing which probably will require reinforcement.
8. Mix or buy the concrete and spread it in the trench. Level it with the tops of the marker pegs.
9. Use the edge of a straight-edged board to chop across the concrete to expel air.
10. Remove the marker pegs and fill the gaps with concrete, smoothing the surface with the board.
11. Leave the profile boards in position and fit string lines to mark wall edges for bricklaying.
12. Mark the positions of the string guidelines for the walls on the concrete strip. Do this either before the concrete sets (a few hours after laying) using a spirit level, straight-edge and brick trowel, or when the concrete is hard, using a chalked straight line.
13. Cover the concrete and let it cure and harden for at least three days before building.
Laying bricks or walling blocks
Before laying any bricks or walling blocks on the strip footing, work out the bond pattern using dry bricks, especially if the wall has any corners or piers (See “Building a brick pier” on page 3). Take a note of how many part bricks you will need to cut (See “Cutting a brick” on page 3). You will have removed the string line (but not the profile boards), while setting the footings. Re-fix the string to the nails on the profile boards, to indicate the position of the front of the wall.
It takes experience to achieve a 10 mm thickness of mortar under a brick every time. If you have never done any bricklaying before, practise laying a few bricks with a pseudo mortar of one part lime and three parts sand. Clean the bricks within two hours so that they can be used in building the wall. Take particular care in positioning and laying the first course – the most crucial part of the job.
You will need:
Brick trowel; spirit level with horizontal and vertical vials; flat, even length of timber; builder’s square; gauge rod with 75 mm markings; pointing trowel; line pins and building line; mortar board; jointing tools; straight-edge.
Bricks or walling blocks; coping or capping bricks; strong mortar; damp-proof membrane about 19 mm wider than the wall thickness, with sanded surface on both sides.
1. Leave the profile boards and string lines in position as a guide until you have completed the first course.
2. Shape the mortar with the trowel so that it looks like a fat sausage pointed at both ends.
3. Slide the trowel underneath the mortar to lift it off.
4. Tip the mortar on to the building surface between the marked lines in position for laying the first brick.
5. Tap the flat of the trowel blade backwards along the mortar to flatten it to a thickness of about 19 mm. The mortar will be pressed down to 10 mm thick by the weight of the brick (see image above).
6. Lay the first brick in position on the mortar in line with the marked guidelines.
If the brick has a frog (indentation on one side), lay it with the frog facing upwards.
7. Lay another brick in the same way a metre or so farther along the line. Do not worry about its position in the bond; it is for levelling only and can be removed later.
8. Place a flat board across the tops of the two bricks and use a spirit level to check that it is horizontal. Use the trowel handle to tap down the highest brick as necessary until both bricks are level.
9. Prepare a mortar bed for the second brick of the course. Before laying the brick, hold it upright and spread mortar for the vertical joint on the end to be butted.
10. Squash the mortar down against all four edges, or it will easily fall off.
11. Lay four or five successive bricks of the course in the same way, then place a spirit level along them to check that they are horizontal. Tap bricks down with a trowel handle as necessary. If a brick is too low, remove it and add more mortar.
12. If the course turns a right-angled corner, use a builder’s square to make sure it is true.
13. After completing the first course, build up at each end and corner with three or four stepped courses. Use the gauge rod to check that each course is at the correct height.
14. Insert line pins into the mortar at each built-up end. Use the line between them as a guide to levelling the top of the second course. Move it up progressively to check the levels of following courses as you lay the bricks between the stepped ends.
15. Point the bricks after laying three of four courses (see “Pointing the joints” on page 3).
16. From time to time, check that the wall is both upright – not leaning – and straight by using a spirit level against it vertically and a straight-edge horizontally.
17. If using a top course of shaped bricks, sandwich the damp-proof membrane into the mortar two courses from the top. If using coping stones, sandwich it into the mortar bed for coping. The damp-proof membrane should overhang about 10 mm on each side.
Cutting a brick
Cutting a brick in half lengthways (closers) is tricky, as the brick is likely to fracture. It is generally easier to cut two quarter-bricks (bats) and lay them end on instead of using a closer. The easiest cutting method is with a brick bolster and club hammer.
1. Pencil in the cutting line round the brick, then score along it with the bolster, tapping it gently with a club hammer.
2. With the brick laid frog down on sand or grass, rest the bolster in the scored line with its handle tilted slightly towards the waste end of the brick. Then strike it hard with a club hammer. The brick should part neatly in two (see image above).
Cutting a block
A walling block can also be cut with a bolster and hammer. Mark the cutting line and continuously score round it, gradually increasing pressure until it breaks cleanly in two. As an alternative, you can use a block splitter.
Using an angle grinder
If you have a lot of bricks to cut, hire a power-driven angle grinder masonry cutter, but handle it with care to avoid an accident. Wear safety spectacles and heavy gloves as a protection from flying fragments.
Pointing the joints
The mortar joints between bricks are shaped so that they shed rainwater and look neat. The commonest shapes used are flush, concave, and weatherstruck (sloped outwards from a recess at the top of the joint).
The shaping, generally known as pointing, can be done after each course before the mortar dries, or left until later using fresh mortar – of a different colour if desired. If pointing is to be left until later, when you have laid a few courses, rake out some of the mortar from each joint to leave a 13 mm-deep recess.
*Flush joint – Made by trimming off the excess mortar with a pointing trowel so that it is in line with the adjoining bricks. Rub the joint smooth with a piece of sacking.
*Concave joint – Made by trimming off the excess mortar with a trowel, then drawing a rounded piece of metal along the joint to give it an inward curve. You can use a bent piece of 15 mm pipe, or a handle from a bucket may be suitable.
*Weatherstruck joint – Made by using the pointing trowel to recess the mortar slightly below the upper brick, and then sloping it to project slightly above the lower brick. Trim off the mortar from the overhang at the base using a straight-edge and the trowel. Shape the vertical joints in the same way, but sloped from side to side, all either to the left or to the right.
Using a roller tool
Pointing can also be done with a roller tool. Different blades can be fitted for shaping different types of joints.
When levelling bricks, you may have to remove some – either to add more mortar to a low brick, or to scrape some off a high brick that will not tap down to the right level. The replaced brick may not stick well because the mortar has lost some of its adhesion. This does not matter as long as it occurs with only an occasional brick. But if the mortar gives no grip at all, scrape it off and start again.
On a hot day, dip each brick in water to wet the surface before laying it. This makes up for dryness in the mortar.
Bricklaying is probably the most expensive of the building trades. You can expect to pay as much to a bricklayer as you pay for the bricks. Bricklayers are in constant demand for major construction work and generally prefer not to do the sort of small jobs needed by many householders. For this reason, apart from the money-saving aspect, it is worth learning a few basic bricklaying skills.
Doing a little of your own brickwork will not make you an instant tradesman; high quality bricklaying can only be done after a lot of experience. But with a little practice you can successfully build low garden walls, barbecues, compost bins – and even a house wall.
Equip yourself with a beginner’s set of tools. Besides these, there are two other important tools that you can make yourself – a corner block (or two) and a notched plate. If you have a lot of bricklaying to do, hire a small mixer and mix the mortar correctly. When you have assembled all the tools necessary to make a start, organise the work area. Sound organisation is more critical in bricklaying than possibly any other trade.
As a beginner, you cannot afford the distractions of having to look around for tools and materials. Take the following steps to organise your work site.
1. Make the area around the site (about 900 mm all around if there is room) as level and as clear of obstructions as possible.
2. Make stacks of bricks – not too high – at least 1 500 mm apart so that you do not have to walk to one end of a long wall to get each brick.
3. Position spot boards between the stacks of bricks so that mortar is always near the spot where you are laying bricks. Ideally, you should take no more than a short step at most to reach the spot board.
4. Make sure tools are clean and ready for use. Do not have the hose running, but do keep a bucket of water near the job. This is for washing dirt off hands, dampening the mortar if necessary, and cleaning tools before the mortar sets.
5. If the job will take longer than a day, keep just enough mortar ingredients near the missing spot to enable you to work for half a day. This will help you develop a better working rhythm.
‘Raking’ the corners
Brick walls are not built by simply laying course upon course. It is standard practice to build up a number of bricks at each end of a wall in a series of steps no higher than 900 mm – the height of 12 bricks – then fill in the intervening space.
Bricklayers have a language all their own: when a corner of brickwork is stepped up in this way it is called “raked” brickwork. It is also referred to as a rack. Apart from the accuracy necessary to get the first course right on the line, this is the most important part of setting out the work. The secret of making successful corners lies in being able to read your spirit level at an angle somewhere between vertical and horizontal.
Each brick laid when raking back is checked for accuracy – both vertically and horizontally. When you reach the top of the “rack”, the work must also be checked for level, from the brick farthest from the corner point of the top brick. Until you gain some experience, build only three or four courses at a time.
When both ends are raked back an equal number of courses, adjust the string line and start filling in. When filling in, use a corner block to position the string line accurately. Use pins at both ends of the line if you prefer, but insert the blades of the pins in vertical (cross) joints so that the line will remain taut. If the line sags, the wall will dip in the middle. Over a long length of wall, the notched plate is wedged between the bricks and the string to support the line and to keep it straight. Repeat the raking process for each new set of corner bricks.
Many beginners make the mistake of deciding on the length of a wall, begin to build, then find that it takes an odd piece of brick to fill in a gap left empty in the middle of the run. Using their gauge rods, professionals mark out a wall to the nearest half-brick – and save themselves a lot of trouble. They call this “making brickwork”.
Whether you are building a straight garden wall, a braai or a house wall, plan your layout to “make brickwork”. Provided they have no openings, straight garden walls, walls with only one corner (an L-shaped wall), and those with two corners can be built to the nearest full brick or half brick.
Where walls have openings, windows, doors and gates, more careful measuring is necessary. It is easier to pack out a window, door or gate frame than it is to cut an odd piece of brick at every course.
1. Use your gauge rod to measure along the footing from the corner of the wall to the full brick closest to the edge of the proposed opening.
2. If there is no objection to having the opening precisely at that point, mark the footing accordingly. If it must be moved, make it a half-brick more or a half-brick less and mark the footing (see image above).
3. Use your gauge rod to mark the other side of the opening, then mark either a half-brick or full brick to conform with the markings on the gauge rod.
4. You can use either a full brick or half-brick at the end of the wall – whichever makes the length of the wall closest to the measurement of your plan.
Building a brick retaining wall
A retaining wall supports a bank of earth on one side, and may be needed in a sloping garden, or as a base for a boundary fence where the neighbouring garden is at a higher level. It can be built of bricks or walling blocks in the usual way, but must be a full-brick wall – about 225 mm thick – built with a strong bond and string mortar.
The strip footing should be set in a trench with the top of the concrete surface about 230 mm below the level of the lower ground, so that the bottom of the front of the wall is a little below ground level. To allow for drainage from the banked soil, make weeper holes through the wall. One way is to leave out the mortar in every other vertical joint on about the second course above the lower ground level.
This is simplest to do between headers. Another way is to angle a plastic or clay pipe through the wall at 1 m intervals.
MAKING MOVEMENT JOINTS
In a long run of wall, a movement joint is needed to allow for shrinkage or expansion of the materials. The joint is a narrow vertical gap about 10 mm wide in the wall and coping, completely separating one length of wall from the next.
Make movement joints at the intervals recommended. Fill in the gap with a strip of bituminised plastic foam and seal it on each side with a mastic masonry filler suitable for outside use.
A RAISED PLANT BED
A hollow bed for planting is simply a wall that completely encloses a small area filled with soil. Build a full-brick wall 215 mm thick either on a strip footing surrounding an area of soil, or on a completely solid surface, such as a patio.
Where there is an earth base to the bed, no drainage is needed in the wall. Where the surface is completely solid, make a series of 10 mm drain holes round the base by leaving gaps through the wall on the first course. Choose a bond that includes headers, and leave out alternate mortar joints between them.
A useful height for a raised bed is 600 mm. If it is any higher, the pressure of the soil as the weather causes it to expand or shrink could force the walls outwards. Do not make the bed wider than about 900 mm. Not only will it take a lot of soil to fill it, but it will be difficult to reach plants in the centre.
Building a brick pier
End pier on half-brick wall
A half-brick (stretcher bond) wall is 110 mm thick. To make an end pier projecting on one side only, lay a header brick against the end stretcher on the first course, then a half bat butted against the header and parallel to the stretcher.
On the second course of the pier, lay two stretcher bricks, then repeat the pattern for alternate courses.
Intermediate pier on half-brick wall
For the first course of an intermediate pier projecting on one side only, lay two header bricks to project from the bond in the place of one of the stretchers at the required positions – at 1 800 mm intervals.
On the second course, the projecting headers are covered with a stretcher, and at the inner end are overlapped by stretchers. To avoid a constant vertical joint on the wall face, use three-quarter bat stretchers with a half bat in between.
Intermediate double pier on full brick wall
For an intermediate pier projecting both sides from a wall built with an English garden wall bond, interrupt the first stretcher course with three pairs of head-on headers with two pairs of head-on closers (or bats) between them. This will project half a brick on each side of the wall.
For the second course, lay two head-on stretchers on each side on the projecting half bricks. Repeat the pattern for alternate courses. The only variation is that on the fourth (header) course, the pier stretchers are alongside headers.
End pier on a full brick wall
For an end pier on a full brick wall built with an English garden wall bond, end the course with two three-quarter bat stretchers. Then lay three headers in line with the stretchers. Place two head-on stretchers on each side so that the pier projects half a brick on each side, and runs half a brick beside the three-quarter bats.
End the second course with three-quarter bats, then butt headers across the pier at each end, with four parallel stretchers between. Repeat the pattern for alternate courses. On the fourth (header) course, no three-quarter bats will be needed.
© Complete Guide to Home Improvement in South Africa, published by Reader’s Digest (1991). Reproduced by arrangement with Heritage Publishing.