As I travel around the Melbourne Suburbs I see lots of brick fences……….. A problem with a large proportion is that they have obvious cracks.
If you don’t believe me just walk around your neighborhood and look at a few brick fences yourself!
So why are there problems with brick fences?
- The actual cost of the wall in both materials and labour is high resulting in people trying to minimise on wall, and supporting pier dimensions.
- Although many people think of brickwork as an inert material it is still subject to expansion and contraction which needs to be accommodated with proper detailing.
- Brick work is actually a fairly brittle structural material which relies on its weight for a lot of its strength. The jointing material of mortar is much weaker than the bricks.
- Due to the considerable weight of brickwork it needs substantial (costly) foundations which will not be subject to any settlement.
- If it’s built on clay there is more chance of movement……The soil below the narrow foundation can gain, or lose, moisture more readily than under a house slab.
- Although it ‘feels’ as solid as a concrete wall it may only have a tenth of the structural strength of a well designed reinforced concrete wall.
Here are a few recommendations;
- Don’t try to save money on the foundation. After all that’s what all those expensive bricks are standing on. A 500mm wide x 300mm deep concrete with trench mesh should be the minimum.
- Brick piers a minimum of 320mm x 320mm with vertical steel reinforcement.
- Minimum wall thickness should be 210mm (double brick)
- Have articulation/expansion joints at 5m intervals.
- Use horizontal steel reinforcement every 6 courses.
- It you are using the wall to retain soil get the wall properly designed.
All sounds too expensive?,,,,,,,,,,,,,,,Perhaps brick piers with infill timber or steel panels may be the way to go!
Remember – “There is no such thing as a cheap brick wall”.
For sizes of brick walls see Brick Dimensions