BRICK ISSUE GUIDANCE :
LIME BLOW IN BRICKWORK
SYMPTONS, PREVENTION AND CURE
Lime Blow occurs when small bits of lime are present in the clay of brick, which can happen for various reasons.
The presence of lime will not normally become evident until the brick has been laid, got wet. As the brick dries out the lime may blow a small part of the brick face away. Sometimes this may happen straight away, sometimes it may take a few wet-dry cycles for the lime to blow the brick face. Sometimes small chalky white 'dots' of lime can be seen in the brick face, showing the lime before it blows the brick face. |
Lime blow is not structural, it is purely a
cosmetic issue. Typically the clay of the brickwork will have become contaminated with lime prior to being turned into a brick and fired. When the brick is fired in a brickwork kiln the lime turns into calcium oxide which then turns into slake when the finished brick is walled and becomes wet. It is the process of 'slaking' that causes the lime to 'blow' the face of the brick. |