Steve Sierleja, builder, distributor and member of San Antonio Sustainable Living has built for thirty years, starting in Pennsylvania with log and post/beam structures and continuing in our area with Faswall, durawall and Quad-Lock.
Now he distributes and builds with BuildBlock, an ICF (insulated concrete form) block manufactured in Bastrop, Texas. (Being locally made in Bastrop earns big LEED credits.)
An insulated concrete form consists of two connected walls of closed cell polystyrene. The blocks are dry stacked and concrete is pumped into the void. Block manufacturers compete based on their innovative variations on the connectors, in the profile of the block and in the size and configuration of the block. ICFs are not a generic product.
After the concrete is poured, standard exterior and interior siding as would be used in stick construction is applied. To run wiring, a hot knife is run in the polystyrene. The wiring is placed in the cut and then spray foam is used to cover it. Plumbing lines can be placed the same way, though they are generally routed through interior walls.
A typical ICF wall has a true R rating of 20 but the effective R rating is 50. There is no infiltration of air. By their nature the buildings hold up well in windstorms. The risk of fire is substantially reduced and property insurance costs are often 30 to 40% lower. Typically they only require one ton of air-conditioning per 1000 to 1200 sq feet.
BuildBlock uses recycled plastic webs to connect the polystyrene which is more durable than metal and which provides easier useful attachment points. They are completely reversable, which makes for more flexible stacking.
BuildBlock corner blocks have one side longer than the other. As any mason knows you want to avoid lining up vertical joints. By stacking a long side on top of short side this is prevented, making for much stronger corners.
Steve has managed to place BuildBlocks in the Lowes at the Rim in San Antonio, in Shertz, Pearland and Pasadena. Just go to the commerical sales desk and they will help you get started.
Steve's contracting company, Custom Homes Ltd, has several projects going including a home near Medina Lake. In December 2008, his commercial operation stacked and poured the new additon to the Wheatsville Co-op in Austin.