1110 RAINIER AVE A DOMESTIC VIOLENCE SERVICES OF SNO CO 2018-01-01 MF Import

� Everett Housing Aufhorif y May �6, 2012 � JN 12080 Page 10 wealher. It is also important that surface v�ater be directed away from temporary slope cuts. The cul slopes should also be backfilled or retained as soon as possible to reduce the potentiai for instabilily. Please note that loose soil can cave suddenly and without warning. Excavation, foundaiion, and utility contractors should 6e made especially aware of this potential danger. These recommendations may need to be modified if the area near the potenlial cuts has been disturbed in the past by utility installation, or if settlement-sensitive utilities are located nearby. All permanent slopes should be inclined no steeper than 2:1 (H:V). Water should not be allowed to floev uncontrolled over the top of any temporary or permanent slope. All permanently exposed slopes should be seeded wilh an appropriate species oi vegetation to reduce erosion and improve the stability of the suriiciai layer of soil. Topsoil is often placed on regraded slopes to promote growth of vegetation. Proper preparation of the regraded surface, and use of appropriate topsoil is necessary lo prevent the topsoil from sliding off the slope. This is most likely to occur foliowing extended wet weather if a silty topsoil is used. On steeper slopes, it may be necessary to "track walk" the slope or cul small grooves across the slope prior to placing the topsoil. DRAINAGE CONSlDERAT/ONS Foundalion drains should be used where (1) crawl spaces or basements will be below a struclure, (2) a slab is below the oulside grade, or (3) the outside grade does not slope dowrnvard from a building. Drains should also be placed at the base of all earth-retaining walls. These dralns should be surrounded by at least 6 inches o( 1-�nch-minus, washed rock and lhen �vrapped in non-woven, geotextile filter fabric (Mirafi 140N, Supac 4NP, or aimilar material). At its highest point, a perforated pipe inveri should be at least 6 inches below the bottom of a slab floor or the level of a crawl space, and it should be sloped for drainage. All roof and surface water drains must be kept separate from the foundation drain system. A typical drain detail is atlached to this report as Plate 9. For the best long-term performance, pertorated PVC pipe is recommended for all subsur(ace drains. If the structure includes an elevator, it may be necessary lo provide special drainage or waterproofing measures for the elevalor pit. If no seepage into the elevator pit is acceptable, it will be necessary to provide a(ooling drain and free-draining wall backfill, and the �valls should be waterproofed. If the footing drain will be loo low to connect to the storm drainage system, then il will likely be necessary to install a pumped sump to discharge the collected water. Alternatively, the elevator pit could be designed to be entirely waterproof; ihis would include designing the pit structure to resisl hydrostatic uplift pre�sures. As a minimum, a vapor retarder, as defined in lhe Slabs•On-Grede section, should be provided in any crawl space area to limil the transmission of water vapor from the underlying soils. Also, an outlet drain is recommended for all crawl spaces to prevent a build up of any �vater that may bypass the footing drains. The excavation and sito should be graded so thai surface water is directed off the site and away from the tops of slopes. Water should not be allowed to stand in any area where foundations, slabs, or pavements are to be conslructed. Final site grading in areas adjacenl to the building should slope atvay al least 2 percent, except where the area is paved. Surface drains should be provided where necessary to prevent ponding of water behind foundation or retaining walls. GEOTECH CONSULTANTS,INC.