It's physically demanding but you should have few problems as you learn to use the tools and materials. Choose a barbecue size which suits the cooktop and ideally is a multiple of full or half bricks, that is, around 240 and 120mm with joints.

Materials for our barbecue cost about $380, with a quality gas barbecue unit, gas bottle and accessories a further $800.

You'll need
Basic brickie's tools: trowel, spirit level, bolster and lump hammer, wheelbarrow, mortar board, shovel, string line, square and joint finishing tool.
350 bricks
8-10 bags concrete mix
2 x 1500mm lengths trench mesh
Formwork timber: 2 x 900mm, 2 x 1800mm,
2 bags cement
1 bag lime
5 bags brickie's sand (blended)
Barbecue unit, gas bottle and timber and hardware for serving area.

Here's how
Formwork
Level a site for the 100mm-thick concrete slab base. Cut formwork to size, nail corners together and securely peg or prop in place. Check the base is square and level in both directions. The formwork is used as a mould for the concrete without further levelling.

You'll need about eight bags of premixed concrete for this area. Have an extra bag or two handy in case of irregularities in concrete depth.

Pour half the concrete into formwork and push in two lengths of trench mesh. Pour remaining concrete over reinforcement. Compact concrete to level of formwork and screed it level. Smooth surface with a wooden float. Let concrete set overnight, then cure it by keeping wet for several days for maximum strength before laying bricks.

Getting started
Dry lay the first row of bricks on the slab and decide on the best layout. Remove bricks and mix the mortar.

Mortar
Mix 1:1:6 parts cement (we used off-white for a pale cream colour), lime and blended brickie's sand in a wheelbarrow, then add water to make a soft mortar that's easy to compress but will not flow through your fingers.

At front corner put down enough mortar for three or four bricks. It should flow off the trowel and form a 30mm high ridge. With a slight wiggle of the wrist, run point of trowel through the mortar to spread it slightly to sides. This is called furrowing and ensures filled horizontal joints. Lay the first brick at the front corner, align it and tap with trowel to bed it into the mortar. Check height with a gauge stick.

Butter the next brick to fill the vertical joint (perpend). Tilt the brick and apply mortar with two or three quick strokes on the end face.

Lay next brick, adjust width of perpend, align and bed it into mortar. Lay the corner brick then fill in the remaining brick in the row. In our case this brick needs to be cut.

Build the entire first course before starting upper courses. Remove excess mortar with trowel, striking it away from brick face without smearing.

Start the next course at the corner overlapping the brick to form a strong bond. As the courses start going up, check brickwork for plumb (vertical) as well as height and level.

On longer runs of brickwork such as the back of the barbecue, build up corners and use a string line set just off the top edge of the row of bricks being laid. The string line must not actually touch the bricks.

Lay a solid brick base under barbecue unit inside perimeter brickwork. Leave a gap in divider wall for the gas hose.

Clean up
Brush off excess mortar with a stiff brush once surface dries a little. After a few days, remove any stain with a 1:10 mixture of hydrochloric acid and water. Always add acid to water (not water to acid) and wear protective clothing. Dampen brickwork, then apply acid. When it stops fizzing, hose down with water.

Setting barbecue unit and gas bottle
Set the unit in place, feed the gas line from the bottle to the unit and fix as per manufacturer's instructions. Place gas bottle in the compartment adjacent and connect the hose via a regulator and gas fuse.

Serving area
Nail pencil-round hardwood decking boards to two hardwood rails for a serving area and fix to walls of barbecue with masonry anchors. Coat timber with a preservative or exterior oil.

Gauge stick
To achieve consistent mortar joints, make a gauge stick. For convenience mark on one edge of your spirit level intervals of 86mm with a felt-tip pen. This corresponds to the thickness of a brick (76mm) plus a mortar joint (10mm).

The level can then be used to check for accurate brick height as well as plumb (vertical).

  Source: Building Barbecues, a Better Homes and Gardens mini workbook (Murdoch Books) ISBN 0864119429