Since the inception of the International Energy Conservation Code I have seen numerous bulletins and emails with information about the best way to achieve the required U-Value for exterior walls to comply with IECC requirements. With all of this information I have yet to see conclusive data on the constructability of any given system. The data presented are empirical at best, and I believe in some cases pure advertising. We are led to believe that scientists have determined that by wrapping a building in insulation, we reduce heat loss. That makes sense when we only consider heat loss, but what happens to the rest of the building?
I have all spent the night in an old house with its frequent noises made by the movement of the framing members as they cool down. And by the way, it doesn’t have to be a really old house—all building materials are affected by thermal movement. A classic example is concrete. One would think that it is stable and without movement. Even in a mass structure like a dam, thermal movement must be compensated for with expansion joints. Our beach house on the Southern Outer Banks of North Carolina is protected by a concrete sea wall 5 miles long and 30 feet deep. In the early days of spring, the expansion joints, which are dry keyed joints, are large enough to fit your fist into the joint. In the late summer that same joint is so tight you cannot even fit a piece of paper into the joint. Wood also moves a considerable amount depending on the temperature and humidity. It moves enough to tear the wood panel in a six-panel door apart if the panel is not floating in the stiles. When we put all of these materials into an assembly like a building, we know there will be movement to be compensated for.
Where I am going with this? I’m trying to show that the new energy codes are putting us, the building industry, into a bad position. Sometime in the near future we could be blamed for constructing sick buildings even though we constructed them in accordance with current codes and standards. This is surprising when we consider the lack of institutional memory. Several years back there was a spate of sick buildings blamed for many aliments suffered by the occupants of these buildings.
Currently many of the new houses in Florida that are in foreclosure are rotting from the inside out. They have simply been closed up without the benefit of the environment conditioning of the interior necessary to maintain them in a habitable condition. We all know from the installation standards and manufacturer’s instructions that environmental conditions must be met when we are putting the building together. Apparently some folks forget that these environment conditions must be maintained for the building to last and be livable.
The energy codes ignore this to a great degree. While it is laudable to reduce the energy consumption of our dwellings and places of work, we must still keep in mind that we cannot live and work in sealed structures. Depending on the climate zone, if a dwelling or building has operable windows, you can bet that the windows will be open. Even in the colder climates there are those of us who sleep with the windows open even in the dead of winter. We have to ask what this does to energy consumption even though the heat is turned down. Of course one of the answers is, we pay the heating bill in our homes, and it is not a big problem in office buildings and commercial structures.
What we need to be on the lookout for are problematic situations that we are already aware of. This is to prevent a callback in the future. If it involves problems with the drywall, you can bet we will get the blame and have to spend the money to correct the problem.
As your technical director I am always on the lookout for what I perceive as potential problems with new code requirements. The hard part is making sure we have an influence on the outcome. Most, if not all, of the new changes are driven by a special interest group with a hired gun leading the charge. With enough advance notice we can get in line and do our best to protect the interests of the wall and ceiling industry.
If you know of any potential problems—or perhaps you have a potential solution, I’d love to hear from you. Feel free to contact me with your comments and concerns.
Donald E. Smith, CCS, is AWCI’s director of technical services. Send your questions to firstname.lastname@example.org, or call him directly at (703) 538.1611.