Wednesday, September 15, 2010
Framing is always one of the most enjoyable parts of building a house (right next to seeing the joy on a homeowner's face when they see their finished home, and almost as enjoyable as getting paid). This is when the rubber meets the road so to speak, when the lines of the blueprint are translated into actual walls and the floor plan comes to life.
Framing also plays an important role in the green building process. For the purposes of LEED certification, framing counts toward material efficiency, durability, energy efficiency, and environmentally friendly products. I'll discuss each one in turn.
As you might imagine, a significant amount of wood goes into the construction of a new home. As it turns out, too much wood. Even after accounting for waste (doing accurate take offs and minimizing scrap are also key elements of LEED), there is simply too much wood in a house.
Building codes and tradition have encouraged 16 inch on center framing. What this means is that the studs on a typical wall are spaced every 16 inches, as are roof rafters, ceiling joists, and floor joists.
Everyone wants a solid house, but why pay for something that is not needed? If done properly, 24" on center framing works just fine, and reduces the amount of lumber in a home by over a third. The truth is, 16 inch on center framing is often just an excuse for sloppy framing. If you do it right, 24" on center framing will result in the same strength and performance, and with significantly lower costs. In this LEED home, our roof rafters, ceiling joists and floor joists are all spaced 24" on center.
Framing plays a key role in durability. Hurricane clips are a good example. We install them on every rafter, and they provide significantly more resistance to wind than simple toe nailing, at a minimal cost. Making certain that the loads in the house, from the roof on down, are properly transferred to the foundation is another aspect of durability. It sounds obvious, but not everyone does it. We do.
For all of its great qualities, wood is not a great insulator. If you can take wood out of the thermal envelope of the home and add insulation the result will be a much more efficient home. We use advanced framing techniques such as two-stud corners and ladder blocking to do just that. Again, it's simple, but not everyone does it. LEED certification is your assurance that your house is both well-built and efficient.
Finally, framing plays a role in the use of environmentally preferable materials. Products such as I-joists and open web floor trusses utilize scrap wood and smaller trees relative to dimensional lumber, and they are more consistent and stronger. At John Marshall Custom Homes we use framing products from local sources as much as possible, and we insist that our wood products are certified as being produced using sustainable practices.
Come by our green home at 631 James Alexander Way in Davidson and see first hand how framing techniques result in a stronger, more efficient, and less costly home.