Most insulation materials although primarily inorganic, contain organic compounds which can support mould growth (e.g. binders). Dust and debris including spores from outdoors may supplement the level of organic materials, naturaly accumulating over time. Therefore, when in the presence of moisture such as humidity or wetting, insulation can sometimes contain actual mould growth. In our investigation we found that visual assessment was inadequate for evaluating the insulation material. Sometimes insulation material that looks clean may contain high levels of mould growth while dirty looking materials do not.
New cementitous materials are naturally protected from mould growth due to the high alkalinity (pH 11.5-12.5). However, due to carbonization, where the Ca(OH)2 in the cement reacts with the CO2 in the air producing CaCO3, pH lowers over time with an ending point of around pH 7-8. High levels of mould can be found even though the materials looks solid and has no visual discoloration indicating water damage.
Investigation of porous materials:
In porous materials, the vast majority of the mould growth can often be found inside the material rather than on the surface. Analyzing bulk samples with the Mycometer test allows measurement of this hidden mould source, something no other method can provide. The bulk samples are weighed and then simply put into the enzyme substrate solution instead of a swab. The time of analysis is the same as with swab samples. The results are given as fluorescence counts per mg material. Contact us for available protocols.
Examples of relevant materials for bulk sampling are:
- Rigid fibrous glass duct liner
- Insulation material e.g. mineral wool and glass wool
- Ceiling Tiles
- Plaster – Mortar - Concrete
Protocols are available for some materials, e.g. insulation materials and in materials containing cement (mortar/plaster/concrete).
- Post remediation verification (PRV)
- Documenting the efficacy of the cleaning of surfaces for mould growth
- Documentation of mould growth
- Documentation that discoloration is NOT mould growth
- Delineation of mould growth where it is non-visible. How much should be cleaned?
- Documenting the cleaning of HVAC systems