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Geotechnical Engineering Investigation Page 15 of 24 New Residential Subdivision 2706 Pock Lane Stockton, CA 95205 March 30, 2021 CTE Job # 25-1097G into and embedded below rough pad soil grade at least 24 inches to prevent moisture migration into structure foundation soils. The post tensioned slab shall be underlain by a four-inch capillary moisture break layer consisting of consolidated aggregate base or sand with a sand equivalent (SE) of 30 or more. Alternatively, the structural mat can be underlain by a 6-inch layer of Class II base. In moisture sensitive areas, a vapor retarder of at least ten-mil thickness (with all laps or penetrations sealed) should be installed over the capillary moisture break. A maximum one-inch layer of similar material may be placed above the vapor retarder to protect the membrane during steel and concrete placement. Prior to the placement of capillary moisture break and vapor retarder, the slab subgrade, if not lime treated, should be kept in a moist condition between 3-5% above optimum to a depth of 18" as verified by a CTE representative. During the construction of the post tensioned foundation system, the concrete should be placed monolithically. Under no circumstances should cold joints form between the footings/grade beams and the slab during construction of the post tensioned foundation. The foundation/slab excavations should be clean(i.e., free of all loose slough) and dry prior to placing steel and concrete. The concrete for the foundation should not be placed against a dry excavation surface. When evaluating wind and seismic conditions the allowable bearing pressure may be increased by one-third. These pressures are net values and therefore the weight of the mat may be neglected for the portion of the mat extending below grade. Based on the above allowable loading the mat shall be designed using a modulus of vertical subgrade reaction of 100 pounds per cubic inch (pci). We estimate that total seismic and static settlements of a post tensioned foundation, loaded as recommended above, to be approximately 1 inch of total settlement and 1/2-inch of differential settlement between structural elements assumed to be on the order of 30 feet.