Stone Masonry 100 Hours Certificate Course

There are 9 lessons in this course:

1 Scope and Nature of Masonry

• Introduction
• The language of masonry
• Masonry tools
• Masonry materials
• Legal requirements
• Foundations
• Joining

2 Cement and Concrete

• Introduction
• Cement
• More types of cement
• Different types of lime
• Mortar
• Concrete
• Concrete masonry units
• Concrete foundations

3 Construction Method and Structural Considerations

• Introduction
• Setting out levels
• Understanding loads
• Types of walls
• Making construction stronger
• Dealing with movement
• Movement joints
• Using moisture controls
• Using metal
• Copings and caps

4 Working with Brick

• Introduction
• Types of bricks
• Laying bricks
• Cavity wall construction

5 Working with Stone

• Introduction
• Types of stone used in construction
• Stone walls
• Stone walls for landscaping
• Free standing stone walls

6 Construction for Fire -Fireplaces, bbq’s, kilns, ovens and fire pits

• Introduction
• How to construct fireplaces and chimneys
• Chimneys that do not work
• Indoor slow combustion burners and wood/coal nurning stoves
• Brick barbecues

7 Landscape Applications & Hybrid construction

• Introduction
• Paving
• Outdoor steps
• Other garden features

8 Repair and Miscellaneous Work

• Introduction
• Paints and sealants
• Plastering walls
• Fixing plaques to masonry
• Damaged walls
• Surface damage and structural damage
• Problems with paving and driveways
• Miscellaneous uses of masonry

9 Building Applications -houses, garden, farm or commercial buildings

• Introduction
• Choosing what materials to use
• Choosing a site
• Setting out buildings
• Basic design considerations
• Legalities
• Special project

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.
Aims

TYPES OF BRICKS

There are different ways to classify bricks. One of the usually ways is according to use.

• Common bricks - used for any general building but with a poor appearance
• Facing bricks - used on exterior walls and chosen for their attractive appearance
• Engineering bricks - a dense brick, often with no frog, used where strength is needed

Bricks can also be classified according to quality i.e. internal (only for internal use), ordinary (external use), and special (for extreme conditions).

Bricks can also be solid, perforated, hollow or cellular.

Clay bricks are by far the most widely used brick. They contain mainly silica and alumina with small amounts of lime, manganese and iron. Different clays give different colours and textures. They are fired in kilns to harden them.

Some other bricks are also used:

• Concrete bricks - these are made with six different compressive strengths from 7 to 40 N/mm2.
• Calcium silicate bricks - also called sand lime bricks, or flint lime bricks, these are made from sand or gravel and lime which is steamed under pressure. Again they are manufactured to six compressive strengths from 14 to 48.5 N/mm2. The lowest strength bricks are only suitable for internal work. Stronger ones can be used for exterior wok and below damp proof courses but they should be used with care sink they are prone to shrinkage.
• Fire bricks - these are moulded from clays which have to be mined rather than surface clays. The type of clay used is called refractory clay. It has more uniform physical and chemical properties and a high fusion (melting) point. Fire bricks are laid using mortar which also has a high fusion point.

LAYING BRICKS

Laying bricks is something that many people can do with moderate success if they take their time; but to lay bricks well takes knowledge first, then practice. To lay bricks fast while maintaining a quality of construction takes even more practice. Usually mortar joints are laid at 10mm thick, so if the brick was 215 x 102.5 x 65mm this would give a wall unit size of 225 x 112.5 x 75mm.
Bonding

Bricks must be bonded properly (i.e. joints must not be laid to make a straight line vertically). Bricks are bonded together by staggering each row (or course) so that each brick in the next course overlaps the brick in the course below (where the overlapped section is called the 'lap'). Normally the overlap is by one quarter of a brick's length but it can be half a brick. Bonding means that there should be no vertical joints that extend beyond one course. Walls that are properly bonded will become a solid single strong mass of wall with resistance to side thrust and lateral stability; but without proper consideration for bonding a wall is nothing more than a stack of individual bricks which lack any overall coherence.
In order to bond a wall, this means that as well as full size bricks you also need some bats or closers. Bats are parts of bricks, usually three quarter length bricks or half bricks. Closers are of three types:

• King closer - tapered from the header to the stretcher face
• Queen closer - half brick or quarter brick cut lengthwise
• Bevelled closer - bevelled from one footer to the other

Choice of Bond

The bond chosen will be governed by considerations such as the location of the brickwork, its use, and how thick the wall is to be. For example, the outer face of a house needs to look good but the walls of a basement would be built for strength. Some common bonds include:

• Flemish bond – probably the most widely used bond for exterior house walls, Flemish is both strong and attractive. It is made by laying alternate headers and stretchers in the same course. The headers in the courses immediately above and below a stretcher are positioned so they are aligned over the centre of the stretcher.
• English bond – this is stronger than Flemish bond and used mainly where strength is a priority. It is made by laying alternate rows of headers and stretchers.
• Stretcher bond – this is used for walls which are only a single course wide. Rows of stretchers are used throughout the construction. The centre of each stretcher lines up with the joint between the two stretchers on the courses above and below.
• Flemish garden wall bond – garden walls are built to save on the cost of facing bricks and the number of headers. Here, rows of bricks are made up of an alternating pattern of one header and three stretchers.
• English garden wall bond – this wall bond has three courses of stretchers to one course of headers.

There are many other types of bonds. Some like herringbone are only suited to very thick walls. Others, like basket weave, are best suited to brick paving.

Locking Your Construction in Place

• Joints - corner joints with acute angles are solved by using bats or closers. Squint bricks and angled bricks may be used on corners with less acute angles e.g. 135 degrees. These bricks can be purchased to suit a range of construction designs.
• Ties – brick ties are used to tie two walls, or leaves, together. This is necessary in cavity walls where the inner wall is able to share some of its static and live loads to the exterior wall through the ties. Cavities have to be of a certain width (typically more than 50mm and less than 75mm), and the inner and outer leaves also have to be of particular thicknesses (usually not less than 90mm). Ties are made of durable material like steel and coated with zinc, galvanised wire, or stainless steel. Different shapes include butterflies, twists and double triangles. Plastic ties may also be used.
• Ties are positioned in the mortar bed as walls are constructed. They can fail for a number of reasons such as poor materials, poor choice (e.g. too short), corrosion from aging (usually only in older buildings), or occasionally because the mortar used has corroded them (e.g. black ash type mortars).

How to Cut Bricks

Sometimes you only need part of a brick to fill a space, for a closer or bat, or when building more complex constructions like arches. To cut the bricks various methods are used. Your choice will be governed by availability of tools as well as skill level in using those tools.

The quickest way to cut a piece off a brick is to use the edge of the blade on a brick trowel. First the brick is marked on each edge by tapping with the trowel. Then the trowel is used to hit swiftly along the line between the two edge marks. This method is fine if the cut edge doesn’t have to be perfect. It should not be attempted on harder bricks since you can quickly ruin your trowel.
A similar level of accuracy can be obtained using a brick hammer. Once again, mark both edges first by tapping with the hammer and then join up the space in between with swift hits of the wedge shaped edge.

A hammer and bolster is the simplest means of cutting bricks with reasonable accuracy. First mark a line around all sides of the brick by holding the bolster in position and tapping gently with the hammer. Once done, you have to place the brick over a support so that it overhangs from where you want to cut it. Make the first proper cut on the shortest face and then finish off on the longest face.
Another option which provides greater accuracy is a special tool called a ‘scutch chisel’, or a ‘scutch hammer’. A scutch chisel is a chisel with a groove in the end into which is placed a blade with a toothed edge. The blade is called the ‘scutch comb’ or ‘drove’. The chisel is used like any other brick chisel by holding in position along the line to be cut and hitting the head with a lump or club hammer. A scotch hammer serves the same purpose but the scotch comb holder is on either one or both ends of the hammer. It’s not as accurate as the scotch chisel since you have to swing the hammer whereas you can hold the chisel exactly where you want it before striking.

Various types of power saw can also be used, an angle grinder being an obvious example, but a proper brick saw gives the best results. These use flowing water down the blade which helps to dampen noise, reduce dust, and increase the accuracy of cut whilst minimising loss due to fracturing of bricks. If other power tools are used they should be fitted with a dust extractor bag to prevent silica particles from being inhaled.

Damp-proofing

Any construction that is exposed to water can be more at risk of deterioration. Buildings have to have damp proof courses so that moisture from the ground doesn't move up the walls. Water must also be stopped from spreading downwards. Barriers to water can be built into a construction in various ways.
A damp-proofing course between the bottom of a wall and the ground (at least 150mm above ground level)

• Inside a concrete slab floor
• Beneath a concrete slab
• Above lintels in cavity walls to prevent downward movement of moisture
• In chimneys and parapets
• Around windows and doors

A waterproof layer plastered on the back of a wall that has soil or anything wet behind it

To stop moisture from entering brickwork, a damp-proof course has to be impervious to water. It also has to be durable so that it will last for the lifetime of the construction. The material used ought to be able to withstand the load placed on it without deteriorating.
There are different options for damp-proofing as follows:

Flexible - these damp-proof courses are the most widely used since they are suited to many situations. Materials used include polythene or plastic, bitumen felt, lead and copper sheeting. They are used exclusively over openings in cavity walls and are ideal where damp-proofing needs to be incorporated into unusual shapes or is stepped.

Semi-rigid – a mastic asphalt course is suitable for dense walls where the damp-proof course is under a heavy load. Semi-rigid layers can also be built from a mix of hard and soft materials.
Rigid – sometimes a more solid damp-proof course is needed. Materials used include epoxy resins and sand, brick and slate, stone or concrete with waterproofing materials added.
Grouts – mixes of cement slurry and polymers can also be applied.