Gypsum Drywall, Moisture, and IAQ
Ongoing
This project brings together research on how gypsum board, paint and other interior sheathing materials respond to moisture and mould. It includes completed chamber tests comparing sheathing materials and the effects of paint sheen on mould growth on gypsum drywall, and a planned collaboration with SMART Canada investigating the indoor-air-quality implications of using gypsum drywall in HVAC return-air systems.
Research streams
Mould resistance across sheathing materials
Controlled chamber testing compared mould growth on paper-faced gypsum and two magnesium oxide boards under warm, humid conditions.
Paint and coatings on drywall
Testing examines how paint sheen changes mould growth on gypsum drywall, extending the research from the board itself to its finished surface.
Gypsum in HVAC return-air systems
Work with SMART Canada will combine practitioner knowledge, codes and research evidence with laboratory testing of material removed from real systems.
Project overview
Drywall, paint and coatings
Paint changes the surface that mould encounters, but different finishes may not provide the same protection when drywall is exposed to warm, humid conditions. Undergraduate research by Samantha Wu and Katy Hui Shan Cao tested how paint sheen affects mould growth on gypsum drywall, extending the lab's material research from the board itself to the coatings used on it.
Comparing sheathing materials
In a completed chamber study, two magnesium oxide boards resisted mould growth better than paper-faced gypsum under the conditions tested. The result provides evidence about material susceptibility and methods for controlled mould testing, while also showing why performance claims need to be tied to specific products and exposure conditions.
Gypsum in return-air systems
Workers who inspect and maintain HVAC return-air plenums and ducting sometimes find gypsum linings visibly degraded. A planned study with SMART Canada will combine a review of codes and published research with practitioner knowledge and laboratory testing of material removed from real systems.
Related paper
- 2024Mould risk model development for a novel interior sheathing material: laboratory testing of magnesium oxide board