Experimental investigation of mold growth risk among typical residential indoor materials: Case study in coastal city, China

Abstract

Mold growth poses significant threats to building structures and occupant health, particularly in regions with high air humidity. Existing mold prediction models involve fewer categories of building materials and are less reliable in predicting complex real environments. This research investigated mold growth risk of ten typical residential indoor materials. Firstly, this work carried out meticulous sampling in a residential building, followed by incubation tests in a controlled mold incubator, and evaluated by the mold growth index. The results revealed varying degrees of mold growth risk among different materials at different relative humidity (RH) levels. Paints exhibited a generally low susceptibility to mold contamination, while panels and wallcovering displayed a higher risk of mold growth. Under high humidity, mold growth was observed in the panels on the first day of inoculation. Conversely, 25 % of the latex paints did not reach index 1 at the end of the experiment. The results showed that below 75 % RH at 25 °C was a safe area for all experimental materials. Moreover, experimental results indicated that a lag approximately one-week in the appearance of mold was observed when the RH was reduced by 10 %. However, the final mold growth index did not differ by more than one grade after the test cycle.