Bob Vila meets with Jim Costello from Superior Walls of America to discuss the difference between precast panels delivered to the site and a traditional poured concrete foundation. The precast panel is made of an outside shell wall of high strength concrete combined with rebar reinforced concrete pillars. The ten-inch thick pillars give a look similar to a traditional stud wall with Styrofoam insulation. Pressure treated furring strips attached to the pillars make drywall or paneling easy to attach. The panels have an R factor, the measure of a materials resistance to the passage of heat, of 5 (concrete block has an R factor of about 2). Polyurethane caulk with special concrete adhesives is added between each panel to insure a tight seal. The panels are attached to each other and the base with pre-installed saddle bolts. A typical home�s installation takes about five hours and without having to wait for the foundation to set or dry, contractors can begin framing immediately. The walls are guaranteed for 15 years compared to poured concrete walls, which generally have a warranty of one year.

Bob talks with Jim Niehoff of the Portland Cement Association about building homes using concrete. For builders, constructing homes with concrete can save a lot of time and give homeowners a very energy-efficient home. Building a home with this combination of concrete and foam can save homeowners about 30-40 percent on heating and cooling costs. Building with concrete is particularly desirable in disaster-prone areas, because it provides stronger protection against hurricanes and tornados. Bob talks with the homeowner, Howard Brickman, about the experience of building the addition with concrete. The process has been very efficient. The crew has only been on the site for seven work days and has accomplished a great deal in that short amount of time. The construction process has eliminated the need for any exterior wall framing or insulation. The shell of the addition is already complete except for the rafters on the roof. The finished addition will look like a traditional shingled home and will be indistinguishable from the original section of the house. The radiant heating system put into the addition was downsized because of the energy savings involved with concrete construction. It is estimated the concrete addition will cost 30 percent as much to heat as the rest of the house.

Bob is joined on the site of the Punta Gorda, Florida, storm-ready home by Jim Crain of Precise Forms. Precise Forms partners with Mercedes Builders to create high-quality, reinforced concrete homes throughout Florida. Precise Forms began in 1967 by supplying cast-in-place forms for subterranean foundations and basements. In 2000 they began to set forms for full wall, cast-in-place houses for Mercedes Homes. Once the forms are set, Bob walks through the layout with Jesse Gonzalez of Mercedes Homes. Gonzalez points to window placements that are encapsulated behind the aluminum forms as they walk past view windows in the family area, past the three bedrooms, bath, laundry, and two-car garage of this four-bedroom home with master suite. Mark Newton of Solid Wall Systems joins Bob as the pour begins. He explains that they are using a 2,000 pound psi, small aggregate concrete mix for the entire pour. We watch as the concrete is pumped into the forms, which are braced at the top by two-by-fours that hold the tops of the forms square to prevent movement as the forms receive the static pressure of the concrete. Newton explains that they will vibrate around all door and window openings before allowing the concrete to set. This will help eliminate voids, honeycombing, or any blowout due to bad adhesion or conformity of the concrete.

Bob talks with homeowner Howard Brickman about drying out of the new addition. Concrete can pose problems for the wood-floor installation business. Brickman's consulting business created a device that measures the relative humidity of the interior of the concrete and predicts what will happen after the concrete is covered with a floor covering. The whole exterior structure of the addition, except for the roof, is made of concrete. It's critical that the concrete that makes up the floor is dried before the wood floor is installed. This is especially true in Southern climates where there is a high amount of humidity.

Bob is at the Mashpee home site for the installation of the pre-cast basement entry system from Bilco. He looks at a finished system and remarks on the light, sturdy doors that are molded of high-density poyethylene, ribbed for strength, yet light weight and low maintenance. He then visits an installation in progress to see how the pre-cast concrete stairs are drilled to accept the threaded steel rods that will join the stairs to the foundation. The faces of the stair system that will receive the butyl resin and bond with the foundation are first primed with a catalyst to help the butyl resin adhere. The resin is laid on in strips that will flatten, spread, and compress as the stairs are lowered into place and pressed against the foundation to form a water-tight seal. The stairs are made of 5,000 PSI (pounds per square inch)concrete that is so dense it doesn't need waterproofing treatment like the foundation. The door leaves are installed last, with pre-molded cutouts for the hardware. These light, ribbed doors are actually as strong as steel, but never need to be scraped, primed, or painted. They are sold as a premium product, at a higher price than traditional steel doors, because they are built to be secure and maintenance-free. These doors shed water by design, and direct it away from the house and the door opening.

After seven days of steady rain, the crew is ready to pour the concrete for the foundation and slab at the Punta Gorda, Florida, storm-ready home. Bob explains how code now dictates that foundations be elevated and supported by a three-course block stem wall set on reinforced footings below the grade. These perimeter stem walls are reinforced with horizontal and vertical number five diameter steel rods or rebar. The stem walls and slab are poured as one to create a seamless slab and foundation. This integral foundation will protect against water intrusion and hydrostatic prssure that lifts slabs and compromises structures when storm surge comes. The concrete is floated and polished to finish the slab before the reinforcing steel rods and mesh are set for the walls. Vertical steel rods are spliced to the reinforcing rods protruding from the foundation, then steel mesh is attached with wire to the rods. Stirrups and rebar create the headers, and spacers are attached to the mesh to keep it centered in the new wall once the concrete is poured.

The slab was poured at the same time as the footing, saving a lot of steps. The process was very streamlined. Insul-Tarp, a combination insulation and a vapor barrier from RadiantMax.com, was used to insulate the slab. The tarp acts as a barrier to the moisture below the slab and provides an insulation value of around R6, which prevents heat loss. The haunched footings, the slab, and any reinforcing are all done in one step. Traditionally a 10'x10' steel reinforcing mesh would go down before the concrete is poured, but that step was eliminated by blending the fibers into the concrete mix. This mesh adds to the cost of the concrete but by an insignificant amount. This method is still much cheaper than the traditional method. The slab is four inches thick. After the concrete has been poured and allowed to set, the diagonals are checked to make sure the slab is completely square and points are perpendicular.

Jesse Bartusek from Bellawood joins Bob for the installation of the Bellawood Brazilian Walnut, also called Ipe. The first step, Bartusek explains, is to monitor the moisture content in the concrete so that there will be no cupping of the wood from excessive moisture levels. A moisture barrier is put down between the concrete and the wood to ensure a dry seat. The sealer and the adhesive are both polyurethane based. Once the adhesive is troweled on, the crew has between 30 and 45 minutes to install the planks. The planks are laid out and hammered with a rubber mallet to put them in place. The crew then tapes the boards because the adhesive has memory and will pull boards back to their initial positions if not held in place. Tapping all the boards in place, or racking out the floor, can force some glue up onto the surface. It must be removed with a special adhesive remover. The patterns and colors in the wood tend to vary because it is a natural product. The eight-layer aluminum oxide finish provides long wear that is guaranteed for 50 years by Bellawood. The tape will stay in place for at least four hours but is recommended for 24.

Bob meets with Brian Kallmeyer from Unilock to talk about the Unilock tumbled concrete pavers. The product starts out as a high density (minimum 8,500 PSI mix) concrete paver. The density is achieve by taking a pretty dry mix with good aggregates like local granite that's put in a 3-story machine that presses it to a very high compaction and compression. They use a standard portland - no more than a typical wet concrete. Originally to tumble the create the antiqued pavers, they would just throw the fresh, shiny, square pavers into an old cement mixer and roll it around. The process has since become more elaborate to meet the growing demand. The resulting product is easy to work with. Unlike the natural stone that it duplicates, these pavers have been made in a mold so they are very dimensionally stable. They can be cleanly cut using a lever action on a guillotine cutter.

Bob talks with Howard Brickman of Brickman Consulting about waterproofing the concrete basement floor. Brickman is putting water down on the floor to make the floor more absorbent for the sealant he will be applying later. To seal the concrete, Brickman will use Bone Dry, a sodium silicate with enzymes, to penetrate and seal up any spaces in the concrete to prevent water intrusion.