Forming and Placing Concrete for the Garage
Starting with the garage will give us covered storage.
Our 8-in.-thick foundation walls vary from a 6-in.-high stubby upon the batholith to 10-ft. retaining walls on massive footings for the basements. Because of their width, we call the retaining wall footings sidewalks and that is what they are used for when forming up the walls.
We use the Gates system of form ties, waler cams, and strongback clips with ¾-in. plywood forms. It is a very robust set up and we are quite confident with our forms. Starting on the outside, we nail a 2×4 to the footing offset from the string by ¾ in. then we lay in the 10 ft. sheets (or less) and start holding it all together with ties and walers. Once the outside is built we place and tie the rebar curtain then build the inside forms. On the high walls we build in a plank for the pump crew and finishers.
Since the garage is unconditioned and we can use it for storage and shop space while building the house, we formed and poured its walls first. That way we could divide labor and simultaneously form the house walls while framing the garage.
After pouring the garage we took apart all of the strong backs and walers and stack them nicely out of the way; collect all of the Gates Cam Locks and Strong Back Clips; and then pull and clean the plywood forms.
The garage footprint is 26 ft. by 24 ft. and it has two levels. Drive in parking above and walk-out basement below for shop space. We framed it up first so that we’d have some space for materials and tools. The floor is 11-7/8 in. Truss Joists on hangers between ledgers and a center girder with a single post. The subfloor is a double layer of AdvanTech, which has stood up well to our rainy season.
The garage walls are 2×6 and sheathed with salvaged 1/2-in. plywood. Architecturally, the 2-in-12 pitch roof and the large soffits will match the volume of the house with its 16-in. TJI rafters. There will be plate-to-plate clear polyurethane panels on the south wall for light.