Why Auckland brick veneer cracks in spring

Auckland clay does not sit still. A veneer that looked perfect in March can show a stepped crack by October, following the perpends down the corner like a staircase. People blame the bricklayer. Sometimes they should. More often the wall was asked to do a job the slab, the control joints, and the ties were never set up to share.

Brick veneer in New Zealand is a rainscreen. It hangs off the frame on ties, sits on a shelf or a rebate, and needs room to move. Miss the control joint, run a long wall past a garage opening with no break, or bed the first course on a slab edge that is already out, and the crack is scheduled. It is waiting for the clay to shrink after a wet winter.

Do not silicone it

Bathroom silicone in a mortar joint traps water and makes the next inspection worse. Photograph the crack in the morning, note whether it opens after a dry week, and look at the downpipe. A soak at the base course will do this on its own. So will a lintel that has rolled, or a pier under 800 mm beside a window.

Mr Singh Brick & Block Laying Ltd, LBP, work this from Sunnyvale across Auckland. Sandeep Singh’s crew are the people you want walking the elevation before anyone cuts bricks out. The number is 020 410 79568.

Repair is a different temperament to new work

You do not smash a whole wall because one corner stepped. You find the cause, cut out what has to come out, re-bed, and match the joint so the patch does not announce itself from the street. Seventies Auckland bricks are slightly uneven and no longer made in that batch. A brick and block laying company Auckland layer will hunt salvage or accept an honest break-line. “We’ll just mix new bricks through” is how you get a tide mark.

New work fails more quietly. Joint reinforcement where it is actually needed — above openings, at corners — not as a superstition. Mortar that is not too strong for a wall that must flex, and not too wet on a west Auckland afternoon. Wind-driven rain finds every open perpend.

What to have ready

Photos. Which elevation faces the weather. Whether the house has moved elsewhere — doors sticking, a gap at the skirting. Who built it, if you know. Access. If this is a sale and the building report has already named the crack, say that. The buyer’s inspector will look at the joint profile, not the brochure.

Spring is when cracks show because the ground has moved and the sun hits the north wall. Fill it with the right mortar after you know why it opened. Call a brick and block laying company Auckland practice that will say if it is a veneer issue or a foundation issue. Those are different invoices, and only one of them is bricks.