Hi All, I have read a few of member's threads who have posted in the past. I though this is mold however I can not clear it. Do I need to buy something mold cleaning stuff? This wall is along our main bath room till our ensuite. In the past the main bathroom had a leaking water problem when we brought the house which B &P report showed us but the seller fixed it with 10 years warranty. Do you think we need to hire the professional to have a look again? Thank you everyone in advance.