Cleaning efflorescence from paving stones.

July 12, 2005

Q: We have a backyard rectangular shaped brick (paving stones) deck. Quite a large number of the bricks (which are grey) have white on them that we cannot
remove. I was hoping there was something that we could use to wash them and remove this unsightly problem.

Lynn, Fort Langley

A: The white that you see forming on the bricks is coming from the cement and under sub straight soil conditions and is called alkaline or efflorescence. To remove from the bricks wash with a muriatic acid mixture of 60% water and 40% muriatic acid. Always wear protective clothing and eye protection when you are working with acid. After washing rinse well and allow to dry. Seal with a paving stone sealer available from Universal Concrete Accessories in Burnaby. Call Brian Slater at 604 299 8551; he will get you going with the product you need.