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 Flemish bonds) 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.
Foundations
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 to level
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.
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.
This article is reproduced
courtesy of DIYdata.com
