Bricklaying & Repointing

White powder on newly installed masonry - bricked up old doorway

Anonymous user 09/03/2024 - 2.56 PM

We had some external brickwork done last summer in the uk where a builder bricked up an old doorway. The weather wasn mixed whilst the work was getting done - some days sunny, some rainy. The builder put a plastic DPC in at the bottom of the wall. The day after the bricks were laid (which from memory were laid after and during rain) some of the bricks themselves were starting to turn a little bit white. The builder wasn’t worried and said it would likely go away. The white marks on the bricks are still there many months later, and some of the mortar has now turned white with a powdery substance on it. We’ve had a lot of rain and snow recently and I wonder if water is somehow getting into the mortar and it’s now drying out leaving salt behind. But it’s just on some of the mortar - not all of it’s affected. The existing bricks surrounding the new brick work are all unaffected as well. Any advice on what could be causing this, how to get rid of it and how to stop it reoccurring?