A few weeks ago, I had the good fortune of attending a class at a certain large contractor/real estate education provider in Minnesota to fulfill my recurring education requirement. It was just a simple one hour Energy Hour class. Still… I went to the class with anticipation of what I might learn about the latest in energy for the state of Minnesota.
About midway through the class a contractor puts up his hand and asks, “Shouldn’t houses breath? Didn’t we go through all of this in the 1970′s? Haven’t we learned anything in 30 years? Who is behind all of this anyway?” The contractor was referring to houses being built airtight. The instructor answers “he didn’t know, it must be all those greeny’s.” 150 contractors burst out in laughter while I just sit there in total shock. For a moment, I thought I was sitting in a class IN 1970. I thought my industry had advanced further than that, but sadly it hasn’t.
Of course, the science of building homes more airtight was settled more than 15 years ago, yet the ignorance of uneducated contractors in our industry continues to persist today. The issue is not the air tightness of a home, the issue is contractors putting homes together not understanding what the heck they are doing. There is a science to constructing homes correctly and unfortunately the building codes can’t really protect home buyers from homes being put together improperly.
Recently, I found a certain national builder actually building homes air tight as required by code but only used one bathroom exhaust fan for internal management of moisture. Now that is just plan wrong…but it passed code!
Quick Facts:
1 – Air tight home construction when combined with controlled ventilation systems actually reduces the probability of mold growth in a building.
2 – Air leakage can be responsible for thirty percent or more of your home’s heating and cooling expenses, adding to mold and rotting of walls, more insects and dirty air. Reducing air infiltration can significantly cut heating and cooling costs, improve building durability, and create a healthier indoor environment.
3 – Water leaks from the exterior of the home or high interior humidity are the primary cause of mold and rotting issues, not air tightness. Air tightness can lead to moisture problems if humidity in the home is not managed properly or if poor choices are made with respect to materials, but is air tightness is NOT the primary reason for mold in walls.
4 – Air barriers are designed to seal the outside from the inside, NOT trap moisture in a wall cavity. An air barrier keeps a home from leaking air from the conditioned to the unconditioned spaces and vice versa. Air leakage contributes to condensation when hot and cold temperatures meet and therefore create at least one of the conditions for mold to grow. If the wall system is not leaking, mold is less likely to grow.
Of course, there is a major difference between air leakage and moisture in walls due to improper construction techniques. When we find mold and rotting issues, nine times out of ten it is due to poor caulking and construction techniques. The answer is not to leave walls open, the answer is to build houses correctly in the first place.
The contractor makes the statement that he “makes a good living fixing these problems.” He is implying that he is fixing walls that mold or rot due to air tightness. He doesn’t even know what the heck he is talking about. He is fixing LEAKING walls. The scary part is he is probably not truly correcting the problem and it may actually repeat itself.
I resolved to keep quiet, get my credits and move on, but was sick to my stomach knowing that most consumers are purchasing homes from a pool of builders who just don’t get it.
