Wall under Valley Gutter growing mushroom

Wendy2896

one of our bedroom wall direct under a valley gutter starts growing mushroom, seems it is in high damp condition ( the wall's other side is my neighbour's bathroom. the valley gutter is cleared last year by my neighbour. and she said it can not be the valley gutter's problem because the wall in her side is not damp.

now my question is what professional I should ask to have a look the wall and identify what causes the damp condition and how to prevent it. how much will it cost roughly.

thanks

iamcornholio

Mushrooms don't just appear over night, and need a lot of water to grow

You have got a persistent damp problem, and the most likely cause is a leak from the valley or the adjacent bit of roof, rather than condensation

You need a reputable roofer to have a look and advise.

A shared valley can leak to just one side