Preparing the Foundation

Project: Building an Addition for an Elderly Parent, Episode 1, Part 2

Bob introduces homeowner Howard Brickman, who is building a new addition for an aging parent that will nearly double the size of his colonial home in Norwell, MA. It showcases concrete building technology that is streamlined, efficient, and versatile.


There were some delays in obtaining a building permit because the home is near a quaking bog that serves as a wildlife habitat and natural filtration system for the town. Steve Ivas, an environment consultant, leads a tour of neighboring Black Pond Bog.  Formed by melting glacial remains, the pond is covered by a moss layer that has since formed a 20-foot thick fibrous mat.  At the home site, a hay-bale buffer was created on the property to protect a connected wetland from erosion or runoff during the project.


At every step, time and materials savings speed the construction and save countless hours of labor.  A monolithic pour, or single pour that would normally take three, is used for the concrete slab and frost walls.  ReddiForm's innovative plastic footing ICF forms are used to create and reinforce the structure.  Insul-Tarp is used to create an insulated vapor barrier and reflect heat back into the living spaces.  Fibers are blended into the concrete mix, eliminating the need for a traditional steel reinforced mesh.

Part 1: Planning for Soil Conditions and Setting the Footings
Part 2: Preparing the Foundation
A monolithic, or single pour, is used to create the slab and frost walls. Todd LaBarge of LaBarge Engineering reviews some of the steps involved in the process. To create the frost wall, they dig down four feet and use innovative insulated forms called ReddiForm blocks that snap together. These polystyrene forms can withstand the pressure of backfilling because they have a structural interior web that reinforces them. The frost wall is backfilled and a rebar cage is inserted into and over the ReddiForm blocks. The front face of the form is cut out and the rebar is extended out across the surface where the slab will be poured. The bearing is then transferred up to the top of the slab, which achieves in one pour what would normally require three: footing, frost wall, and floating slab. A column pad is put in place to increase the load for the load-bearing wall. The product used for under-slab insulation is called Insul-Tarp, which can be laid out quickly and easily, saving time and labor costs. This is an all-in-one reflective and insulated vapor barrier. When the radiant tubing is put down over the barrier, the heat will reflect back into the living space instead of passing into the ground.
Part 3: Pouring the Foundation and Starting the Walls
More and more homeowners are converting their houses into multi-generational homes for themselves, their children, and their aging parents. In Norwell, MA, Bob Vila meets a couple making room for a mother-in-law.