There are three parts to building a solid exterior wall, including sinking the footing, laying the bricks and applying a smooth rendered finish. Tackle it as a complete DIY job or get a tradie to help with the tougher tasks such as the footing then do the bricklaying and rendering yourself.
Make it legal
Check council requirements as most building projects like this require a development application with plans and measurements. Wait for approval before beginning the work.
Building a solid wall
Sink the footing
Lay the bricks
Apply the render
How to make render
Mark out the trench squared off the existing wall and use a small excavator with a 300mm bucket to dig, checking the depth. Square the sides with a spade and remove debris.
TIP The trench required for this wall was 6000 x 300 x 500mm deep.
Position a prefabricated cage in the trench then lay lengths of steel pipe across it 1500mm apart, using tie wire to suspend the cage 50mm clear of the sides and floor.
TIP We used 6000mm lengths of 12mm three-bar steel cage.
As the concrete is poured, level it roughly and ensure the top of the cage is covered by 50mm then use a spirit level to screed the surface level.
TIP To find the volume of concrete multiply the trench dimensions 6000 x 300 x 500mm = 0.9 cubic metres.
Mark the base course on the footing to build the corners, stepping out three brick lengths and up to seven courses high, spacing the corners so you don’t have to cut bricks to fit.
TIP Allow 240mm for the brick length and the mortar joint.
Insert brickie line pins into mortar joints to set out a stringline. Spread and furrow mortar 25mm thick along a metre of the last course, mortar the end of each brick, bed and tap it to the stringline. Strike the joints flush with the brickwork, removing excess mortar.
Position five courses of engaged piers parallel to the wall and every sixth course perpendicular to overlap and lock into the wall.
TIP We used five piers but you may need a different number depending on what your wall will be used for.
If installing a bearer position galvanised strapping between the wall and piers to secure it, notching the perpendicular bricks so the strapping goes freely between them. Continue laying courses to the top of the wall, using a spirit level to check for plumb.
Lay dropsheets and dampen the wall then use a hawk render board and steel render trowel to apply the mix.
TIP Work from the top, applying render with short upward strokes then smoothing in a circular motion.
First let it set slightly then screed with a straightedge, holding it vertically and working left to right in a sawing motion. Fill any depressions and smooth the surface again, leaving it to harden for up to 15 minutes.
First sprinkle it lightly with water then smooth in a circular motion using a timber float, detailing any corners using a small metal corner trowel to prevent damage later.
As the render firms and dries, rub the surface in a circular motion using a flat sponge.
TIP Leave the wall to cure for four weeks. Before painting rub it with a brick to remove the sand film.