5105 CHINOOK DR 2016-01-01 MF Import

aEainst the wall to prcvcnt thc ouild-up of hydrustatic pressurc on thc wall. Thc chimncy drain should consist of a minimum 12 in�h width of pca gravel or'/. inch �v�shcd drain rock place immcdiatcly udjacent to concrete wall extending from the footing dram to within 2 fcet of the ground surface. The upper t�vo feet should be backfilled with a lo�v permeability soil to discourage surface runo(T fmm entering the wall drainage systen.. Approved drainage boards.such as Inca Mat or Mira Drain, should be placcd to extend fiom approximatcly two fcet below the top of the wall down to hydraulically tie into thc footing drain system. Rackfill otthe foundalion walls outside of the chimney drain should be placed in approsimate 12 inch loose IifLs and compacted to a medium dense condilion around 90 percent of the modified Proctor mnximum dry density. A higher degree of compaction is �ot rec.�mmended as this may increase the pressures acting on the basement walls. Thc onsitc soil may bc uscd for wall compaction provided that thc soil moisturc content will allow adequate compaction oCthc wall backfill. Keeping the excavated soil from the foundation excavation covered u�th plastic shceting will help insure that the soil may bc uscd for wall backfill. I Floor Suppurt The residence will utilize both crawl space and slah-on grade floors. Thc crawlspacc soil should be covercd with a moisturc barricr to reduce the potential for moisturc transfer from the �ound. The slab-on-grade floor should be cast utop medium dense or Jenser native s.znd or compacted swclural hackfill around the foundation elemenu. A capillary break of 4 inahes of pea gravel should be placed atop the prepared iloor subgrade. A moisture b;uriP- should be placed atop the capillary break malcrial prior to casting thc (loor slab. All concrcte placements should be pertormed in accordance �+�th curtcnt American Concrete Institute (ACI) standards. Drainagc Considcrations A perimcter foundation drain should be establishcJ to protect the foundatinn/crawlspace from ground watcr intrusion. "fhc Icvcl of thr fiiundation drain shuuld bc set at, or slightly bclow, Uic base of the footing ele��ation. The drain should consist of 4 inch di�meter, rigid, perfiirated, PVC dr<tin pipc and should bc sct lo allow for gravity dischargc. Tlic drain pipc should bc surroundcd hy a minimum of 6 inchcs of pca gravcl or washcd drain rock.. Roof drains should not lie into thc footing drain but should bc collectcd in a scp.vatc, tightlinc drain. 'I hc pmperty was undcrlain by dcnsc sand sedimcn�s with a modcratc cai ''^ to infiltratc st�rm w�lcr runofl: It is our undcrslandinF Uial an infihration trcnch will hc c J across thc north sidc of thc property. (t is our npinicm thnt a pro�xrly dcvclopcd infiltrah� .�nch will allnw thc m.ijnrity �f slc�rm water nmotT to inliltrate back into the ground. "I'he c�vcrflow nut of the trench should bc sct to dischargc at thc northcast comcr of thc prnperty. Conclusion '3ased on our ::ite reconnaiss:uice and suhsurtace exploratiuns Ihc site appcars to he swtahlr firr thc ruposeJ develupmenl provideJ the recommendations presented hen�in are properly implcmentcd. The proposed replacement of the single family residencr �aill not have :�n adverse atTecl ��n thc suhjcct property or un adjacrnl propertics. Our findings and recommendations pruvided �n Ihis report were prepared in accurdance with gcncrally acccplcd pnnciplcs of cnginccrind eeolo�y and gcotcchnical cnginecring as practiced in BGC, pllc 14267 209"' �venue Nfi WooAinville, W� 98077 (425) 273-5062 _ � I3�� ,