4808 BELVEDERE AVE 2016-01-01 MF Import

Timberbuild Homes JN 05357 September 20, 2005 Page 4 be harmful to the health of the occupants. The designer ar architect must consider the potential vapor sources and likely occupant uses, and provide sufficient ventilation, either passive or mechan�cal, to prevent a build up of excessive water vapor within the planneni structure. Geotech Consultants, Inc. should be allo�oed to review the final development plans to verify that the recommendations presented in this report are adequately addressed in the design. Such a plan review would be additional work beyond the current scope of work far this study, and �t may include revisions to our recommendations to accommodate site, development, s^a �eotechnical constraints that become more evident during the review process. We recommend including this report, in its entirety, in the project contract documents. This report should also be provided to any future property owners so they will be aware of our findings and recommendations. SEISM/C CONSIDERATIONS The site is located within Seismic Zone 3, as �Ilustrated on Figure No. 16-2 of the 1997 Uniform Building Code (UBC). In accordance with Table 16-J of the 1997 UBC, the site soil profile within 100 feet of the ground surface is best represented by Soil Profile Type Sp (Stiff Soil). Under the 2003 Intemational Building Code (IBC), the Soil Class would be D. The site soils are not susceptible to seismic liquefaction because of their dense nature and/or the absence of near- surface groundwater. CONVENTIONAL FOUNDATIONS The proposed residence can be supported on conventional continuous and spread fool'ngs bearing on undisturbed, medium-dense or denser, native sand soil, or on structural fill placed above this competent native soil. See the section entitled General Earihwork and Structura/ F111 for recommendations regarding the placement and compaction of structural fill beneath structures. Adequate compaction of structural fill should be verified with frequent density testing during fill placernent. Prior to placing structural fill beneath foundations, ttie excavation should be observed by the geotechnical engineer to document that adequate bearing soils have been exposed. We recommend that continuous and individual spread footings have minimum widths of 16 and 24 inches, respectively. Exterior footing� should also be bottomed at least 18 inches belo� � the lowest adjacent finish ground surface for protection against frost and erosion. The local building codes should be reviewed to determine if diHerent footing widths or embedment depths are required. Footing subgrades must be cleaned of loose or disturbed soil pnor to pouring concrete. Depending upon site and equipment constraints, t� may require removing the disturbed soil by hand. Depending on the final site grades, overexcavation may be required below the footings to expose competent native soil. Unless lean concrete is used to fill an overexcavated hole, the overexcavation must be at least as wide at the bottom ss the sum of the depth oi the overexcavation and the footing width. For example, an overexcavation extending 2 feet below the bottom of a 2-foot-wide footing must be at least 4 feet wide at the base ot the excavation. If lean concrete is used, the overexcavation need only s�Rend 6 inches beyond the edges of the faoting. An allowable bParing pressure of 2,000 pounds per square foot (ps� supported on soils as noted above. A one-third increase in this desig used when considering short-term wind or seismic loads. For tha GEOTECH CONSULTANTS, INC is appropriate for footings n bearing pressure may be above design critena, it is