Bricks: How to Prevent Cracks in Brickwork
Brick is one of the most used material on construction and housing industry. Working with bricks can be a little tricky and confusing. Some contractors have failed to execute some simple steps and have paid the price with costly reparations after the job has been completed. Try following these ideas and you will prevent cracks in brickwork.
Bricks Expansion Joint
Bricks, like other construction materials will change in volume with changes on temperature. It will all depend where the brick is located and what conditions are being exerted upon it.
Bricks will also increase in size due to expansion by moisture and the absorption of water. Engineers will calculate how much it will expand following some basic calculations and studying the behavior of the materials acting upon it.
Using expansion joints in your brickwork, will separate your bricks into small segments, in which, each segment will act individually, and will behave separate from other segments. The expansion joints will reduce brick cracking by changes in temperature, moisture, creep and/or settlement, either horizontally or vertically.
Use pre-molded foam or < a href="http://www.dupontelastomers.com/products/neoprene/neoprene.asp">neoprene in the brick expansion joint. This can be done, by leaving a continuous opening through the brick wythe and filling it. Finish this joint with backer rod and elastomeric sealant material to prevent moisture and water going into the brick joint.
Very important make sure that the expansion joint materials run through the full thickness of the wythe. This will avoid that mortar, and other debris will clog the joint
Do not use incompressible material in the joint.
Bricks Vertical Joint
Every joint in brickwork is different. There are a lot of conditions varying from one scene to another, so don’t treat every joint the same way.
Vertical joints in brickwork ideally will be placed every 25 feet. This is a good rule of thumb.
The engineer should locate the brick expansion joints, not the mason. This is a complex technical issue and should be treated with all responsibility.
Vertical joints should be located at corners, offsets, setbacks, opening, wall intersection, changes in direction, height and long walls.
Brick expansion joints should be placed where different walls encounter, reducing thus the possibility of cracks due to differential settlement. The joint must be located in the interior corner or at least 12” from the corner, creating a stable connection to other members of the building.
Brick Horizontal Joint
Horizontal joints must be located underneath the shelf angle, but please remove temporary shims used to hold the angle in position during the construction process.
Sometimes using lipped bricks, with at least a half inch in depth, is required for large horizontal joints, because they reduce the impact of the joint. Lipped bricks should be made by manufacturer, and not in the project itself. This will allow a greater quality and reduce the errors due to weak bricks. Finally do not allow contact between the lipped brick and the brickwork below, it might cause problems in the future with its integrity.
