There are more choices than ever before in home building materials. The long awaited acceptance of green materials has given us a wide array of possibilities that have not been seen as a mainstream option in previous decades. When looking at materials the most important aspects are durability, energy efficiency and ecological soundness. Appearance is also a consideration, but largely a matter of taste.
Home Building Materials: Insulated Concrete
There are several different construction methods involving insulated concrete. One of the most common is the insulated concrete panel. This is a prefabricated panel, anywhere from six to 16 inches thick, which contains two to six inches of either polyurethane or polystyrene insulation sealed within concrete which is from two to six inches thick on each side. Panels are created offsite in a factory, and delivered to your home. They can be assembled into a home in one or two days.
Another form of insulated concrete is the insulated concrete form. The forms are easily built molds which are poured on site once placed. Yet another method is to build a home completely out of insulation panels covered with wire mesh. Then shotcrete is sprayed onto the panels. This is the most economical method of building with insulated concrete.
Concrete is extremely durable, probably more than any other substance. It neither burns nor melts, it can stand winds up to 180 mph, and it is very earthquake resistant.
Unfortunately it is a terrible insulator, so the entire R-value depends on the polyurethane or polystyrene. The thickness and density of this material can yield substantial R-values, as the concrete protects it completely from deterioration or damage. For maximum R-values, the thicker the insulation layer, the better. Also check the individual manufacturer’s R value, because the quality does vary from one product to another.
Insulated concrete is ecologically sound because it does not pollute, and doesn’t in any way interfere with non-renewable resources. Its durability could be easily measured in hundreds of years, and the R value of the thickest panels exceeds or matches top R values of any material.
New stick built homes are usually built with two by six pine studs, after decades of two by fours. This is partially due to the need for thicker insulation cavities, and partially due to complaints that cultivated pine deliberately grown for timber was not as strong as naturally grown lumber. Two by six stud walls are definitely the best way to go in stick built construction. Extra heavy floor joists, made of at least two by ten inch lumber, are also important to create a lasting and stable floor that does not sag, creak or collapse with age. Again thick heavy material with plenty of room for insulation is the key to getting durability and R-value. Closed cell insulation is far superior to fiberglass batts and currently leads the industry in insulation value.
Structural insulated panels are panels of polystyrene or polyurethane sandwiched between sheets of OSB plywood. While not as substantial as concrete panels, they are amazingly durable when covered with exterior siding. The construction is extremely fast. A home can be built in a day or two as huge wall panels and roof panels are placed with a crane. A home can literally be built in a day with these panels. Of course unlike insulated concrete, this home will have to be sided and drywall applied. Still construction is economical, fast and very durable. Best of all it gets top R-values because of the thickness of insulation. Most panel cores are five or six inches thick.
Stone is a very ancient building material, but in modern times most stone homes are really stone veneer. The home is stick built and then covered with a thin layer of stone. Stone is not a good insulator and tends to seep moisture, but it is very strong, and extremely attractive. When used in conjunction with other materials containing insulation it creates a very beautiful home, and adds strength and durability. It is an exceptionally good material to use in conjunction with insulated concrete.
Wood is a good, but not perfect insulator. While thick logs may be inferior in R-value to the best in insulated concrete or a stick built homes with six inches of closed cell insulation, they are probably among the best of the second choices, and they are certainly cost effective. Log panels offer the best of both worlds, with thinner logs, placed on studs with an ample cavity for more insulation. Some log panels have logs on both sides and insulation inside. These take most of the work out of construction. The benefits of log construction include, ease of installation, a decent R-value though results vary, and best of all economy. Log panels used in conjunction with closed cell or polyurethane insulation can be a very good solution to efficient low cost home building.
The R-value of brick is less than optimal, and it has gradually lost favor in construction after dominating the market in the sixties and seventies. It is still used almost universally as a foundation material, and is often used for aesthetic purposes as an exterior siding. It can even be used as an interior wall treatment. Thin ‘bricks’ less than an inch thick can be used in interior design. Overall brick requires insulation to be competitive in R-value. It is durable though, and it can also be very attractive.
Offering an unbelievably low price, and a competitive R value of 20 as is, used shipping containers are a great value for those who aren’t too proud to use them. They are actually very popular and while R-20 isn’t a top rating, with just a little added insulation they could be pulled up to an R-30 or 40 and still qualify for energy star. Used shipping containers are all about creative use, and part of that creativity is placing them, arranging them. The other part is deciding how to improve them. One can cover them with insulation panels and siding, or one could put the insulation on the inside, though that would only increase their one fatal flaw which is their long narrow design. Not many people want to sacrifice another six inches off a room that is already less than eight feet wide. Adding a roof and well insulated attic also helps hold the HVAC in.
There are many other natural and ecologically sound materials which work in dry climates. They include adobe, rammed earth and papercrete. These materials are natural and extremely ecologically sound, but they loose durability in wet climates. They should be avoided in humid, flood prone or rainy areas, but they are perfect for dry climates. It is important to consider the durability of any material before using it on your home. That includes roofing materials, so always pay a little extra for a longer life on your roofing.
For more information about building materials and home planning, download our 98 page free book and read the many other articles on this site. When considering building materials consider durability, your climate, R-value, cost effectiveness and ecological concerns when selecting home building materials.