Moisture Testing

Moisture when elevated in building materials will allow the spores of moulds to start to grow in as little time as 24 hrs.  Elevated moisture can also create anaerobic odours to form behind walls.  Part of all my building inspections entails using accurate tools to measure the moisture content of materials in the home.  I use both contact and non contact moisture meters with extension probes to get into all areas of a wall structure. 

Caution should be noted on companies that claim they use thermal imaging cameras to detect moisture or moulds behind walls.  A thermal camera shows a difference between the thermal temperatures of a wall.  In most cases this is from insulation gaps or cold spots.  The use of thermal imaging cameras is far overrated and it just looks like a cool machine the inspector has.  It is one tool that needs to be used sparingly and by someone with a lot of training to interpret the image results.  I use multiple tools that are appropriate for the materials and situation and know their limits.

Moulds can form on the surface of wood and other cellulose based materials in as little as 15% moisture content on the surface.  Concrete can have moisture levels of 20% when dry.  That means that any wood in direct contact with concrete can absorb enough moisture to allow moulds to form.  Those 1970’s rec rooms in the basement with the sub floors, or finished basement walls.  Moisture testing is part of all general indoor air quality inspections and mould inspections.


© The House Doc 2011