Ask a tradesperson


Mould (white powder) on internal wall - at corresponding point on external wall, bricks have turned black

Hi there,
We have an external facing wall which has white powder growing on it. We thought it was damp so sanded down and sealed it with a sealant but it has come back. At the corresponding point on the external wall the bricks have turned black. I am presuming the weird growth is mold due to damp but can not see any leak or cause for the damp - any ideas??
Thanks in advance

1 Answer from a MyBuilder Bricklayer

Best Answer

Hi there, there maybe a couple of reasons why this is happening, the white mould you see is salt being drawn through the brick work due to damp, if it's on the ground floor it could be the dpc (damp proof course) failing or poor ventilation or even just the pointing not being up to scratch. As a temporary fix to stop the salts striking through, take the affected area back to brick, mix a sand and cement render with a waterproof additive in it and apply, then replaster. Hope this helps. Plasterplus


Answered 8th Dec 2013

Post your job to find high quality tradespeople and get free quotes

Can’t find an answer? Ask a new question

Question Categories