How To Build a Dwarf Brick Wall
Things you’ll need
- Spirit level
- String line
- Brick Cavity ties (if double brick wall)
- an awareness of the Building Code and Australian Standards for Brick Walls.
You should start by designing your dwarf (<1 Metre tall) wall on a piece of paper.
Be sure to include all of these:
- Where is the wall going to be built?
- Is there anything in the way? (services, tree roots, plants, etc.)
- Dimensions of wall. (Standard House Brick: length = 230mm, height = 76mm, mortar joint = 10mm)
- Required footings / foundations
- What type of bricks to use?
- How long it will take?
- Clean up
A brick measures 230 x 110 x 76 mm and can vary slightly from brick to brick. Allow 59 bricks per squared metre of surface area. (This includes a percentage for wastage).
To work out the surface area of the wall, multiply the height by the length = surface area m2.
Now all you need to do is multiply the surface area by 59 and this will give you your brick amount. For a wall with two skins of brick simply double the quantity.
E.g. Double brick wall, 1 metre high and 4 metres long:
1 x 4 = 4m2 surface area
4m2 x 59 = 236 number of bricks for each skin
236 x 2 = 472 total number of bricks for the project
(Be sure to include for piers and any courses below natural ground level).
A trench usually 450mm x 450mm for a double brick wall one metre high, is suitable.
The trench should be dug out of firm soil or clay. If you want your first course of bricks to be below ground dig a further 100mm.
For a footing 4 metres in length you will need just less than 1 metre cubed of concrete.
When ordering concrete be sure to state that you require the strength at 20mpa, or you can buy pre-mixed bags at the hardware store.
To start, simply wheel-barrow the concrete into the footing. Be sure to work the concrete by poking it to bring up any air holes.
Level out the poured footing with your trowel and spirit level.
Roughen up the surface to create a good bond with the first course.
Allow the footing to cure (strengthen) for at least 48 hours. Be sure to spray the setting concrete with water at regular intervals. Do not drown it, simply keep it wet.
On sloping ground you will need to step the footing.
Laying the first course
Set out the first course of bricks without using mortar on to the footing to be sure it all works out, and fits properly. Don’t forget to allow 10mm for the mortar joint.
If this is your first time laying a wall, it is ideal to have a dry run first, and get used to using the spirit level. Check the level of your wall both vertically and horizontally.
Make your mortar mix by mixing 1 part cement to 5 parts bricky sand (1:5). Add only enough water to make it workable. A plasticiser agent may be used to improve the workability of the mortar. Follow manufacturers instructions if you do use one.
It is wise to only mix what you can use before it dries out on you – usually one wheelbarrow at a time.
Using your trowel, place the mortar on the footing, lay your first course of bricks on top of the mortar, and be sure you place mortar in the brick joint to that 10mm we’ve been talking about. The first course is the most important as it guides the rest of the wall! Take your time to get it right.
Check that the first course is level and straight. It is recommended to set up a string line for perfection and move the string up with each course of bricks.
Once the first course is laid, place some mortar on top of it. Again, be sure to have at least 10mm between every course.
Laying one course at a time, work your way up the wall until you achieve the desired height.
If you are constructing a double brick wall, start the second skin when the first skin is two courses high. Allow brick face to brick face to be 230mm. You can do two courses of each wall to do both skins of brick at the same time.
The brick face may be cleaned when the mortar is semi-dry. Use a wet sponge for this.
Other points to consider
Don’t forget to include anything you might plan to have in the wall, e.g. ornaments, boxes, openings, etc. For any openings be sure to place a steel flat bar to support the opening. Check with your hardware on what type of bar to use. Type and sizes of steel flat bars depend on the opening you desire.
There you have it! Your new brick wall.