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Why are there gaps in brick walls?
Those gaps are called “weep holes” — a building code requirement that drains water out of brick exterior walls. Typically, behind the brick is a 1.5-inch cavity or air space and then the wood structure. Those gaps are called “weep holes” — a building code requirement that drains water out of brick exterior walls.
Why are expansion joints required in brick walls?
An expansion joint separates brick masonry into segments to prevent cracking caused by changes in temperature, moisture expansion, elastic deformation, settlement and creep. A control joint determines the location of cracks in concrete or concrete masonry construction due to volume changes resulting from shrinkage.
Why are weep holes used?
The inclusion of weep holes in masonry walls is intended to serve two purposes: Ventilation: They allow ventilating air to the back of a wall to help prevent mildew, dry rot and damp which might otherwise reduce the life or performance of building materials such as cavity wall-ties, cavity insulation and so on.
Why are bricks offset?
Most brick bonds require bricks (or other masonry units) of the same size or at least compatible sizes. But if you stack them so that the joints are staggered, or are offset, between neighboring courses, the bricks are essentially woven together. In this way, the bond adds strength to the construction to make a.
What is a brick weep hole?
A weep, a weep hole, or a weep-brick is a small opening that allows water to drain from within an assembly. Weeps are located at the bottom of the object to allow for drainage; the weep hole must be sized adequately to overcome surface tension.
Why do bricks expand?
Causes of Expansion There is a three-dimensional time-dependent increase in the size of each brick when it is exposed to the atmosphere after leaving the kiln. This causes increasing length, height and width of brick walls with time.
How long can a brick wall be without an expansion joint?
In general, experience suggests that movement joints in clay brickwork should be spaced at approximately 10 – 12 metres. PD 6697 states that in no case should joints exceed 15 metres and the spacing of the first joint from an internal or external angle should not exceed half of the general spacing.
Why do they stagger bricks?
In building walls, brick bats(half bricks) are used so the joints of the bricks stagger. This staggering gives the lower and upper bricks stability and strength, as to not cause a fracture line in the mortar.
What is header and stretcher in brick?
Header is the shorter square face of the brick which measures 9cm x 9cm. While Stretcher bond is used for the construction of walls of half brick thickness whereas header bond is used for the construction of walls with full brick thickness which measures 18cm.
What could have caused this brick wall to collapse?
We can see that this collapsed brick wall was a structural brick foundation, and the soil piled up suggests it was done in by pressure from wet earth – a drainage or roof drainage problem may have been the root cause of this collapse.
What are normal Expansion cracks in brick walls?
THERMAL EXPANSION CRACKS in BRICK, usually diagonal or stair-stepped, often at building corners where roof spillage is concentrated. Our photo (above) of step cracks in a structural brick wall also shows that the upper section of the wall has bulged outwards past the lower or right hand section of this structure.
What are the most common defects in brickwork?
The most common example of this defect is the damage that occurs to a brick wall when a steel lintel over a window or door is caulked tightly between the brick and the steel. Moisture penetrating the brick wall through cracks or mortar joints is trapped around the steel lintel.
What happens to brick walls when moisture builds up?
Unlike thermal expansion and contraction, dimensional changes in brick due to moisture are irreversible. Brick walls are relatively rigid in comparison to the overall building which moves due to a number of factors.