Even in this economy, some folks are having the joyous experience of planning to build a new home. If you happen to know which end of a hammer to swing, or know whom to hire to swing that hammer for you, there is great joy in helping design and produce a new home.
One of the first steps in building a new home is the foundation. There are a lot of options for building foundations. The foundation system that is used the most here in New England is the full basement.
The basement allows us a lot of extra storage space and gives us a place for the heating system and easy access to plumbing and wiring, at least for the first floor.
The basement is usually made with walls that are either cement block or poured concrete that is 8 to 10 inches thick. Insulation is sometimes ignored with traditional concrete basements. The 10-inch-thick basement wall has an insulation value of about R-1, the same as a single pane of
glass. The thermal mass of the concrete wall makes it seem like more, but that is deceiving.
There are some alternative systems for building basements. The first one is an insulated concrete form, or ICF. They are like big adult plastic foam Lego blocks.
The blocks nest together and are filled with concrete that is pumped into a hollow core. This can be a fun do-it-yourself project, but there is always the possibility of a “blowout” if the blocks are not installed properly. When a blowout occurs, the concrete flows out the hole that blows in the forms and everyone scrambles to stem the flow of the concrete out of the forms. A bad time, but not as bad as it sounds.
Another alternative foundation system is the all-weather wood foundation or insulated wood foundation. This system uses pressure-treated lumber to construct a foundation system that is stick-built and waterproof.
These are permanent foundation systems that are relatively easy to build and are very fast to install. All basement installations need proper drainage and insulation.
Another foundation system that is frequently being used is the frost-protected shallow foundation, or concrete slab. It is also known as a floating slab or Alaskan slab. We did this type of foundation on the first house we built. This is a low-cost and quick foundation.
It is a great way to integrate a low-cost radiant floor heating system into your home when you build on a floating slab.
I am not as smitten with this foundation as I was 35 years ago. It is difficult to insulate to the degree that today’s energy costs warrant and it brings all the wooden parts of your house too close to the ground. Buildings should be at least 8 inches off the ground, but 12 inches is better. This is difficult to do with a floating slab.
Another concept that I think has merit but is seldom used is building on posts. This is a throwback to the “back to the land” builders of the 1970s and ’80s who were building out of pocket. This concept was quite inexpensive and quick, and fairly reliable when using pressure-treated lumber. It also usually meant cold floors since the floors were never insulated very well.
Living in the 21st century has its pluses. The big one is that we have access to foam insulation. A building on posts can easily be insulated by installing sheet foam underneath the floor or by spraying foam insulation under the floor.
Although this concept is a little out there for Maine, it is used in Southern states where flooding might be an issue. This concept is also probably going have a negative effect in terms of valuation. Appraisers like more traditional foundations.
Change is sometimes slow to come in traditional New England. And that is not always a bad thing. It is, however, good to think outside the box when trying to make our homes more affordable, initially and beyond.
Questions for Tom Gocze should be mailed to The Home Page, Bangor Daily News, P.O. Box 1329, Bangor 04402-1329. A library of reference material and a home-project blog are at bangordailynews.com/thehomepage.