JUNE LAKE RESIDENCE
This foundation was located in the eastern Sierra community of June Lake, CA. The site was on the side of a granite mountain and presented many challenges to the general contractor, the excavator, and us. We incorporated many different construction techniques to place this foundation on this particular lot.
The lot itself was aggressively sloped and located about ¾ mile off of the main road at the end of a very narrow lane. This presented logistical problems as we did not have the open space for materials, vehicles, and maneuvering. The concrete mixers could not turn around so they backed the trucks up the entire narrow road to the jobsite. Over 15,000 pounds of rebar was dropped at the base of the access road and later moved by us to the pad. In addition, there were numerous large granite boulders throughout the site. It took a month and a half with a 50,000 lb rock hammer on a big excavator to clear enough of the rocks away for the preliminary pad.
When we first started laying out the footing, there was one enormous boulder that protruded into the interior stairwell. The rock was blasted with dynamite and then chiseled by hand to provide clearance for the stairs. The footings were on multiple elevations and wove their way over rocks and around 400 year old trees. We drilled and epoxied rebar into the boulders to attach the foundation to the hillside. At one point on the lowest level, the footings were almost 11’ wide. The garage wall was 16’ high and in places, 18” thick. The change in elevation from the bottom of the first footing to the top of the highest wall was over 29’.
The foundation required several special inspections including a review by the structural engineer before the footing was poured and numerous inspections by the geotechnical engineer. The geotechnical engineer actually supervised us installing the rebar into the granite.
The footing step from the garage level to one of the upper levels was 4’6” wide and 16’ tall. It used over 35,000 lbs of concrete alone. To hold it in place, we drilled and epoxied threaded rods into the granite and built a framework of 4×6 beams and covered it with plywood to make a form. All of this work had to be completed in place using scaffolding.
Due to the design of the house and the site, the formwork for the foundation walls utilized both our aluminum panel system and our wood forms and had approximately 20 steps with several different wall angles.