As a professional home inspector I find most people are un-educated on mould and whether or not it is affecting their home. There is a lot of hype on mould right now and people are walking around their potential purchase property sniffing for musty odours and looking for tell tale traces of mould. I would like to address some of the more common items found during a home inspection, which although might be a form of mould, should not scare away prospective buyers.
These items of in no specific order, just ranked as they come to mind:
Cold Rooms – These rooms are usually located under porches and are always below grade. The ceiling of cold rooms often contains the wood used to form the concrete porch above and is of no issue. Value of wood was not significant enough to justify labour to remove. Any, back on topic, these rooms are meant to be cold, hence the term cold room, and they should contain at least on screened vent to the exterior for ventilation. Plugging up these vents will lead to your cold room eminating a must odour which may spread to the rest of your basement.
Attic Exhaust Fans – Wish I had a dollar for every bathroom exhaust fan that vented directly into attic or was just put close to roof vent. When you are venting warm moist air, being close to a roof vent doesn’t cut the mustard. When warm air comes into contact with the cold air of your attic it meets its dew point and turns to moisture, which then stays in your attic. this occurance also applies to attic exhaust ducts made of wire and plastic, ( your know the cheap dryer duct that is not rated for use with most dryers) well it performs just as well in your attic. Once again not being insulated allows the warm moist air from your home to turn to moisture as soon as it hits cold air. I have heard stories of these ducts collecting so much water and ice that they become blocked.
Some exhaust ducts discharge down from your vented soffit. When your louvers of the exhaust cover are pointed towards the building which directs the warm moist air against wall where it usually will rise and re-enter your attic, especially if there is any wind. It is always better to vent out a gable end or use a roof vent. I have seen many cases where the sheathing directly above the vent discharge has the beginnings of mould growth.
