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� KLEINFELDER 2. Foundations It is our opinion that the proposed structures can be supported on spread and/or continuous foundations bearing on the existing soils or on properly placed Engineered Fill. We recommend that all foundations extend a minimum depth of 18 inches below the lowest adjacent finished soil subgrade, interior or exterior, whichever controls. Below that depth, moisture fluctuations should be reduced. Any soft soils or debris encountered in the foundation excavations should be overexcavated to stable soil and recompacted, free of debris. We recommend continuous foundations around the perimeter of the structures to provide a barrier against moisture migration beneath interior concrete slab-on-grade floors. The recommended minimum width of all foundations is 12 inches. With the foundations supported on existing soils, the recommended maximum allowable soil bearing pressure for the structures is 2,000 pounds per square foot (psf) for dead plus live loads. This value can be increased by 1/3 for the total of all loads, including wind and seismic forces. The bottom of foundations should be well tamped to provide a firm base. If cracks develop in the soils because of drying, the cracked soils should be sealed by light sprinkling. In any case, the foundation excavations should be slightly moistened just prior to placing concrete in order to aid in its curing. We recommend that the actual foundation and reinforcement design be provided by the structural engineer. We note that the above-stated bearing pressure is a net value, and the weight of concrete in the portions of the foundations which extend below grade can be neglected in proportioning the foundations. We recommend that all foundation excavations on this project be observed by a representative of our firm. The purpose of the observations will be to confirm that the soils exposed are the same as those on which our recommendations are based and to observe for any soft or disturbed soils in the foundation excavations. 3. Settlement For the assumed structure loads, the total settlement is not expected to exceed approximately 1/2 inch with the structures supported on existing soils prepared as recommended in this report. Differential settlement can be assumed to be approximately 1/2 this value. Most of the settlement is expected to occur during the construction period shortly after the loads are applied. 20-4280-0I.Gol/2019R150 Page 4 of 12 April 14, 1999 Copyright 1999 Kleinfelder,Inc.