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Building with Polystyrene Forms and Concrete

The project in Norwell, Massachusetts, involves putting an addition on an existing house to create an in-law suite. A lower-level garage is being built with a spacious suite above. The area has been excavated and the slab and footing poured. The pour was done in one step. A number of products were used to make the slab-and-footing pour faster and easier. Insul-Tarp, an innovative all-in-one vapor barrier and insulation product was used underneath the floor slab. ReddiForm polystyrene blocks or ICFs are being used for the walls. Bob talks with Ron Ardres from ReddiForm about the ReddiForm process. ReddiForm is a modification of the original ICF concept. The blocks are simple in design and can be laid out in a number of ways. This layout flexibility reduces the waste factor to about two percent. The blocks are lightweight but strong enough to support heavy weight and resist high compression. Steel is added as reinforcement to the structure. Holes are drilled into the slab through the cells in the ReddiForm blocks to hold steel dowels that will act as reinforcement and tie down. The blocks are glued to the floor for additional reinforcement. Rebar is also added horizontally throughout the structure. Additional rebar reinforcement can be added as specified to support the bearing loads. The ReddiForm system improves construction speed and helps economize projects by reducing steps and labor. In this home, the blocks will be stacked seven-and-a-half feet high to create a basement and a two-car garage. Once the basement walls are complete, foam forms will be put in place horizontally over the structure to act as the first floor slab. The slab and the walls will be poured in one continuous pour. More information