DIY Life

Whether you're planning to build a new home, remodel your existing home, build an outdoor storage shed, or put up an addition, you've got choices when it comes to the wall you erect. Some of these choices are more traditional and some of them are newer, green building technology.

Wall construction with insulated concrete forms

Insulated concrete forms (ICFs) are another rising star in wall construction technology. These are also panel-like yet different from SIPs. They are blocks constructed with two sheets of Styrofoam with a void between them. Like SIPs, they are designed by the architect or engineer, assembled by a manufacturer, and delivered to the job site.

Once they've been delivered, they're assembled as specified on the blueprint. Once in place, the void in the blocks forming the wall are poured with reinforced concrete. The resulting wall is both strong and insulated on both sides.

The pros and cons

Like SIPs, ICFs form a nearly air-tight structure. This makes it an Energy Star candidate which means a lot for the home's equity. Also, there is little to no scrap to deal with. This not only makes it green and renewable, but it saves big bucks on labor and disposal overhead.

This particular wall technology is well-suited for areas that are prone to high winds, wild fires, and the like. Due to the acoustic and fire-proof aspects, these are being used in interior demising walls (separating units in duplexes or hotels).

The insulation provided by the Styrofoam can be rated up to R-25 depending on the specified thickness! Exterior walls can be finished with any method used with stick framing - siding, brick, stucco, ect.

And in conclusion...

That pretty much wraps up our overview of wall construction technology. I'm becoming a big fan the green methods: SIPs and ICFs, although they lend themselves more to new construction and additions.

Structural insulated panels (called SIPs in the industry) are just now making big inroads into the residential market. This is more common in custom homes than in cookie-cutter subdivisions. The panels are basically a sandwich.

These panels have a core of rigid foam plastic insulation with sheet OSB (Oriented Strand Board) on both sides. Unlike the types of framing materials we've already covered, SIPs are custom-built by a manufacturer to the specifications of the architect or building engineer.

Once they're delivered to the job site, the carpenters assemble them. They can be used not only in the walls, but in the floor and roof as well.

The pros and cons of building with SIPs

The resulting structure is nearly air-tight. This is a huge pro because it means an energy savings of 50% over a wood framed structure! Another pro is that the building process yields almost no scrap. This, plus the energy savings, puts the home on the fast track to an Energy Star certification.

Due to the reduced construction time, the cost of building with SIPs is roughly equal to that of more conventional framing methods.

One con of SIPs is that it takes training to install properly. Many contractors have yet to take the leap, and for DIY'ers, there is a learning curve involved. But that being said, this is a great choice for exterior walls. Next, we'll examine ICFs, a good choice for both exterior and interior walls.

Metal framing; commercial and residential construction

Metal studs are made of galvanized steel. They generally come in two grades: structural, which is used for exterior and load-bearing walls, and light gauge, which is used for interior walls. It's also very handy for radius walls and accents.

Although metal framing is used almost exclusively in commercial building, it's starting to see some action in the residential market. Some builders specialize in it.

Pros and cons of metal framing

There are many pros to framing with metal studs. Walls go up very fast. On light gauge studs and track, no saw is required for cutting, just use a pair of aviation snips. Structural studs do require a chop saw, but this also goes very fast.

Metal studs have "keyways" cut in them to run conduit through; there's no need to use a time-consuming hole saw like with stick framing. The stock is very straight and true so the finished walls are very straight. When hanging drywall, if the joint is a little off, the stud can be flexed slightly.

Of course, metal studs aren't flammable, so that's a big plus. At worst it turn to spaghetti under extreme heat, but by the time that happens, chances are that all the occupants will be out of the structure anyway. Oddly, I haven't heard of any insurance companies giving a rate break for this.

On the con side, metal framing also generates scrap. It can be recycled, but the money it brings is so low that most people just landfill it.

Now, lets move on to newer, greener wall construction systems!

Traditional residential framing

Wood stud framing, also known as stick framing, is the most used method of building both interior and exterior walls. The most common studs and top and bottom plates are made out of pine. Using pine keeps the price down since its easy to work and grows very quickly. It's a very renewable resource.

In the old days, when carpenters erected a house that was two stories or more, the method used was balloon framing. This means that the studs on the exterior wall went all the way up. This made for some very long stock; quite inconvenient. It was time for something a little more manageable.

The answer was a framing method called platform framing. This started to be the preferred method during the 1920's. Aptly named, the upper stories were built with normal length studs on the "platform" made by the top of the lower story. Not only were materials standardized, but construction was much easier.

Pros and cons of wood stud framing

On the pro side, wooden studs are very inexpensive, especially when bought in bulk. It's a pretty competitive market, with most stock coming from the U.S. and Canada. (Finally, something not from China!) It's also easy to work with. Since it's a soft wood, it cuts easily.

On the con side, most of it is cut to fit at the job site. This makes for a lot of scrap, which is the antithesis of building green. Luckily, some of this scrap can got to facilities that make fuel for pellet stoves. This is done when it's economically feasible.

Another problem is that many studs are warped, which makes it hard to apply drywall at times. And of course, since it's wood, it burns readily. Not a great trait in a home. But the chances for a catastrophic fire are greatly diminished with the next wall framing technology we'll talk about: metal studs.