Anti-Mould Paint: The Solution to Drywall Protection?
Trevor Mauch
Prince of Wales Secondary
Floor Location : J 169 H

My Science Fair experiment was to investigate the qualities and effectiveness of so-called anti-mould paint when it came to preventing mould from growing on drywall in the harshest of conditions. Mould, a type of fungi that can grow indoors and outdoors, is a massive problem for many households around the world. Moulds can have a serious negative impact on human health, and it is incredibly important to be able to prevent indoor growth, or anywhere people and animals may live. I decided to test the claims made by the makers of anti-mould paint, compared to standard paint, and bought drywall to test the paint on. My hypothesis was that if Behr Marquee Anti-Mould Paint is used on drywall, mould would not grow as quickly as with Glidden Essentials Regular Paint, due to the chemical component Isothiazolinone in Anti-Mould Paint, which controls and kills mould. With the 30 3x3" pieces of drywall, I painted 5 pieces for each of 6 catagories. These catagories were Anti-Mould Paint (Behr Marquee), Regular Paint (Glidden Essentials), Primer (Kilz Premium Primer), Anti-Mould Paint with Primer, Regular Paint with Primer, and drywall with No Paint. These pieces of drywall were then labeled and placed in sealed bags with a 1x1x1" piece of soaked sponge and a 1x1x1cm cube of Mozzerella cheese with Aspergillus mould present. These bags were monitored and mould growth was recorded every 3 days for a period of 12 days. After the 12 days, Regular Paint drywall had an average total growth area of 14.4 square centimeters, whereas Anti-Mould Paint had an average growth area of 12.6 square centimeters. The drywall category with the least growth was Anti-Mould Paint and Primer with an average of just 5.6 cm2 after the 12 days of growth. When observed in damp conditions with mould spores already present, I discovered that Isothiazolinone, a chemical ingredient in anti-mould paint, prevented most growth but some Aspergillus and Statchybotrys Atra still grew on the drywall.