The Handyman's Pocket Book; Brickwork.

BRICKWORK

For ordinary home use there are two kinds of bricks; the Fletton which is of good hard quality but of a not very pleasant new red colour, and the facing brick which looks much more attractive but is more expensive.  The choice depends upon the purpose for which the bricks are needed.  Frequently both are used in the same job, the cheaper Flettons being used for foundations and in other places where they are not seen.  The size of bricks can be taken as 9 in. by 4.5 in. by 3 in.  In fact they are smaller than this, but calculations can be based on them since the mortar seams have to be allowed for.  They are sold by the thousand, though small quantities can usually be obtained from builders' merchants.

Fig. 2 Stretcher Bond for 4.5-in wall.

QUANTITIES.  To estimate the quantity of bricks required for a job the simplest way is to reckon the number required for each course, and then multiply by the number of courses high.  Take a 44.5-in. wall 6 ft. long and 2 ft. high.  There are eight bricks in one course, and the 2-ft. wall needs eight courses.  Consequently 64 bricks are needed.  This is a very simple example.  Allowance has to be made for the footing which is generally wider, for any return walls, window and other openings.  The same principle of working to the number of bricks in each course and multiplying by the number of courses can be followed, however.  Remember to allow for the thickness of the wall.  For instance a 9-in. wall of the same length and height as the above example would take double the quantity of bricks. 

TERMS.  It is as well to know the terms applied to brickwork.

They are shown in Fig. 1.

• Course.  This is any one horizontal row of bricks.
• Header.  A brick the end of which shows at the wall face.
• Stretcher.  A brick with its long side showing at the wall face.
• Closer.  A brick or part of a brick which is less than the standard width.
• Bed joint.  A horizontal mortar joint.
• Perpend.  An upright mortar joint.
• Quoin.  A corner brick.
• Frog.  The recess generally cast in one side of the brick.
• Bond.  The particular formation of the bricks in a wall.

Fig. 3.  9-in. wall built in English Bond.

BOND.  The simplest bond is that used in a 4.5-in. wall, known as stretcher bond.  It could be used for any light work which does not reach to any great height-a low wall, coal bunker, base for small timber greenhouse, etc.  The vertical joints occur in the middle of the bricks of the adjoining courses.  At the corners they overlap each other.  Where a wall ends as to the left in Fig. 2 it is necessary to use half bricks in every other course, and the broken end is placed inwards.

Bricks are never used directly on earth, and a foundation of concrete laid in a trench is needed.  Apart from forming a firm base for the bricks it spreads the load over a wider area.  The foundation should be about twice the thickness of the wall in width.  This is shown at A,  Fig. 2.  If the bricks are to sustain much weight a footing can be formed of a row of headers, these resting upon a still wider concrete foundation as at B.

When a 9-in. wall is used English bond is a satisfactory method of laying.  It is shown in Fig. 3.  Note specially the corner where closers are needed.  The footing for a 9-in. wall is given at A, Fig. 3.

FOUNDATION.  The concrete foundation is the first necessity, and a trench to receive it should be dug out.  The depth of this depends on the job and upon the nature of the ground.  The concrete foundation is invariably below the general earth surface, and when there is a footing (see Figs. 2 and 3) this also and generally one course of ordinary brickwork is below ground.  The trench depth and width can be decided accordingly.

Fig. 4. Pegs to mark trench.   A. simple square.

Fig. 5. Levelling Pegs.                                   Fig. 6. Lines Pegged 

Mark out the position of the trench, driving in corner position pegs as in Fig. 4.  When a rectangular shape is required as in a building, a large square can be made by the 3 . 4 . 5 method shown at A, Fig. 4.  If the three strips are nailed together to these sizes a right-angled triangle is bound to be formed.  Additional pegs are required to enable the lines which mark the sides of the trenches to be stretched.  The corner position pegs cannot be used because they would fall away when the trench is dug.  Dig the trench, making sure that the bottom is firm.  Loose earth is useless as a foundation.  A pick axe driven in will give a good idea of it firmness.

To enable the concrete to be brought to an even level a series of pegs should be driven into the middle of the trench at intervals of about 5 ft.  The tops of all the posts should line up with the surface of the concrete, and they should be tested with a straight edge and spirit level as in Fig. 5 to see that they are level.  If the sides show any tendency to fall in, pieces of wood shuttering should be fixed to them, side-to-side struts being used to hold them.  They are removed when the concrete has set.

A suitable concrete mix is: I cement, 2.5 sand, and 4 coarse aggregate, and 0.5 to 0.75 water.  This mixed separately (see under concrete) and is poured into the trench and rammed well in.  It is brought to the level of the top of the posts.

MORTAR.  Either a lime-cement or an all-cement mortar can be used.  For the former use 1 cement, 1 lime, and 4 sand.  The sand and lime are mixed thoroughly first and the cement added immediately before use.  If hydrated dry lime is used the entire mix may be done in one operation.  Cement mortar requires 1 cement and 3-4 sand.  These are mixed together dry, the whole being turned over to a fresh position three times.  The water is added from the rose of a watering can to form a workable mix.  Only make up enough for the number of bricks you can lay in one operation.  Setting begins within half an hour of mixing and the mortar is of little value if used once this happens.  Make a point of turning over the mix two or three times whilst working.  Incidentally, avoid brick laying in frosty weather as the mortar is spoilt.

Bricks must be damped before being laid as otherwise the moisture is absorbed from the mortar.  The best plan is to spray them with water half an hour or so before use, using a watering can.

LINE OF BRICKWORK.  Continuing the example already given, set lines on pegs to give the line of the brickwork on the concrete foundation.  Spread the mortar on the foundation and press the bottom course of bricks into ti to leave a joint about 0.5 in. thick.  Any squeezed-out mortar is picked up with the trowel and thrown on to the brickwork.  Assuming that a footing is being used the appearance will be that shown in Fig. 6.

CORNERS.  Now begins the brick laying proper.  As a 4.5-in. wall is being built, stretch lines afresh 2.25 in. from the centre line of the headers forming the footing, as a guide to keeping the first course of bricks in line.  Build up four courses of bricks at the corners as in Fig. 7, taking care to keep the outer surfaces upright.  If you have no plum line (A) you can use a large square as at B, placing a spirit level on the horizontal arm.  Pick up the mortar with trowel and place it in the position the brick is to occupy-you will soon learn to judge how much to pick up.  Also cover the end of the brick with a pat of mortar to form the upright joint.

The four corners being laid the intervening spaces are filled in course by course, lines being held in the joints as shown in Fig. 7 as a guide to keeping the courses level and plumb.  The simplest way of finishing off is to draw the trowel along the joint to cut off all surplus mortar.  As the trowel in drawn along with its edge level with the upper edge of the joint it will depress the mortar slightly at this point and make it flush with the bottom edge.  At the same time it will leave a smooth finish.  Beginners may find it easier to use a putty knife.  If there is any surplus mortar on the face of the brickwork it can be washed off with clean water and a brush after a couple of hours.  Do not use dirty water which has had cement in it.  It will discolour the brickwork.

CUTTING BRICKS.  When a brick has to be cut the professional strikes it all round with the trowel and then knocks off the surplus.  Beginners are advised to use a bricklayer's bolster as shown in Fig. 7 C.  A light blow is given on each side to mark it.  The brick is then placed on a firm surface and the bolster tapped smartly.

Fig. 7. Corners built up and lines stretched.

REPOINTING.  This is often needed in old brickwork.  The operation is fairly simple, but certain precautions must be taken if the result is to be successful.  The first job is to rake out the old joints to give the mortar a reasonable depth as in Fig. 8.  The professional uses a special form of pick pointed at one side and having a chisel edge at the other.  If this is not available a narrow cold chisel and hammer will have to be used.  The depth should be from 0.5 in. to 0.75 in., and when the edges of the bricks have crumbled and the old mortar is weak it is advisable to cut in to 1 in.  All loose particles, dust and so on are then brushed away.  A wire brush is handy for this.

Just before starting the pointing damp all the raked-out seams thoroughly.  Have a can of water and an old brush, and go over the whole.  In hot weather it will probably be necessary to go over the work a second time.  Unless this is done the dry brickwork will absorb the moisture from the mortar and cause the latter to drop out.  Whilst speaking of weather, never attempt re-pointing during frost.  The new mortar will only drop out.

The mortar can be equal quantities of cement and sand, though many prefer a mixture of 1 part cement, 2 parts non-hydraulic lime hydrate, and 9 parts sand.  The former makes a stronger mortar, but it may be too strong for the brickwork causing the latter to crumble at the edges.  The cement-lime mortar is more easily worked with the trowel.  It should be well pressed in and finished smooth in accordance with the rest of the brickwork.  A common finish is known as weathered pointing, and is shown in Fig. 9.   The trowel is drawn along the seam at an angle as at B so that the mortar is pressed slightly in at the top.  This will cause an uneven edge to appear at the bottom owing to the mortar being pressed out.  This is trimmed with a knife and straight-edge as at C.  

An old table knife ground at an angle can be used.  Generally the unwanted mortar drops away; otherwise it is easily flicked off with the knife.  The mortar is best held on what is known as a hawk (see Fig. 11, B).  Do not make up more mortar at a time than you can deal with in half an hour of working, and turn it over frequently.

When the seam has to be hollow-recessed as in Fig. 10 it can be finished by drawing a piece of rounded hardwood along as in Fig. 11, A.  Here again any pressed out mortar should be removed before it hardens.  As a rule the straight-edge is not necessary, the knife alone being used.