Before you build or add an addition to your home, size up your structural options. Each has ecological and economic pros and cons.
While wood framing is the most common and familiar type of home structure, you have other options, including insulating concrete forms (ICFs), structural insulated panels (SIPs) and lightweight concrete blocks. Of course, if you’re adventurous, many other systems have been around for decades, including log homes, straw bale, cordwood and even Earthships. Not every method of construction may be right for your geography, but most technologies can be modified to accommodate your taste and your region. For the purposes of this primer, however, let’s stick to the structural systems your builder is most likely to know and understand.
WOOD FRAMING OLD AND NEW
Wood, by its very nature, is a green product. If forests are managed properly, trees grow back. How do you know if forests are being treated with respect? Look for lumber that is certified by the The Forest Stewardship Council
www.fsc.org or the Sustainable Forestry Initiative
www.sfiprogram.org. Typically, energy-efficient builders prefer 2x6 lumber for vertical studs in wall cavities because the wider space allows for more insulation.
Another more recent wood framing technology is called engineered wood products (EWP). Products such as studs and joists are created in a factory with special water-resistant glues and fibers from leftover mill lumber or fast-growing tree species. They are pressed and glued into lightweight floor joists, rafters or other structural pieces. The green advantages? First, engineered products use more of the tree— there’s virtually no waste. Second, they tend to be more stable and straight than dimensional lumber. The downside? Certain products need to be stored carefully and installed exactly as intended, or they can lose their structural integrity.
WOOD FRAMING -
VIRTUES
> Renewable (if forest is well managed)
> Familiar to contractors
> Excellent durability
CAVEATS
> May create unwanted thermal bridging
> Requires skilled labor
ARXX ICFS
With an effective insulating value of up to R-50 (depending on insulation thickness). ARXX insulating concrete forms can withstand 200 mph winds and have a 2-to 5-hour fire rating. The forms are made with no ozone-depleting agents. and sheathing or drywall can be attached directly to the vertical plastic sections of the forms.
www.arxx.net
LP SOLIDSTART I-JOISTS
The wood used to create these sturdy engineered joists comes from small, fast-growing trees, not old growth timber, and the resins used contain no urea formaldehyde. The product is available in long lengths and can be a major labor saver.
www.lpcorp.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84