Expert: Bruce E. Johnson - 1/4/2010

Question
We built a new home in 2005. We notiiced our vinyl fllors curling up, floors warping and wet spots in our bedroom ceilings upstairs. We notified the builder and were told that the humidity in the house was high because the attic was not ventillated enough. Apparently they vents installed were facing the direction of he wind and could not exhaust the moisture because the wind would blow the moisture back into the attic. The problem was "fixed". Now I have mold growing on the ceiling and walls of the bedrooms. The odd thing is that it is only growing on the walls on the front of the house and my bedroom and bathroom are the coldest rooms upstairs for some unknown reason and have the most mold in them. Could this still be from poor ventillation? could it be from not enough insulation?  

Answer
Hi Tina, humidity inside your home should be easily handled by your air conditioning equipment.  The normal range for interior humidity should be around 40-50% for comfort.  Attic ventilation shouldn't have anything to do with this.  Attic insulation and wall insulation may be factors but I would look at your heating and cooling equipment first.  It sounds like the HVAC equipment is undersized or is not being used enough to remove the excess moisture in the air. Look in you local phone directory and see if there is anyone in the "waterproofing" or "insulation" categories that can do infra-red studies of your home.  By doing an infra-red consultation you can pinpoint heat and cold entering and exiting the house envelope.  This may help determine the areas of moisture infiltration if they exist.   I hope this information helps please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com