1315 MADRONA AVE 2016-01-01 MF Import

Geo[echnical Engineenn� �eport 1313 Madrona Avenue Everett, Washington March 11, 2013 FtiN F�le No 2793-G01 A Page 8 All wall backfili should be weli compacted. Care shoutd be taken to prevent the bwldup or excess lateral sod pressures due to overcompaction of the wall backf�ll Slabs-On-Grade Slab-on-grade araas should be prepared as recommended in the Site Preparation and Grading subsection. Slabs should be supported on medium dense or fumer naUve soi!s, or on siructural fili extend�ng [o these soils. Where moisture control is a concern, we recommend that slabs be underlain by 5 inches of pea gravel (or use as a capillary break. A suitable vapor barrier, such as heavy plastic sheeting, should be placed over the capillary break An addibonal 2-inch-thick damp sand blanket can be used to cover the vapor barrier to protect the membrane and to aid in curing the concrete. This will also help prevent cement paste bleeding down in�o the capillary break through joints or tears m the vapor barrier. The capillary break rnateri2l should be connected to the footing drains to provide posrtive dramage. Drainage lNe recommend that runo(f from impervious surfaces, such as roofs, dnveway and access roadways, be collected and routed ro an appropr�ate stormwater discharge syslem. The fini,hed ground surface should be sloped at a gradien? of 5 percent mmimum for a distance of at least 10 feet away irom the buildings, or to an approved method of diverting water frorn the foundation, per IBC Surface water should be collected by permanent catch basins and drain lines, and be discha�ged into a storm drain system. We recommend that footing drains be used around all of the structures where masture centrcl is important. The underlying glacial dri(t may pond �vater that could accumulate it is good practice to use footing drains installed at least 1 foot below ihe planned (inishe,d floor slab or crawlspace elevation to provide drainage for the crawispace. At a minimum, crawlspaces should be sloped to drain to an ouilet tied to the drainage sys:em. If drains are omitted around slab-on-grade floors where moiswre control is important, the slzb should be a minimum cf 1 foot above surrounding grades. Where used, tooting drains should consist of 4-inch-diameter, perforated PVC pipe Ihat is surrounded by free-drairnng matenal, such as pea gravel Footing drains should discharge u�to [ightlines leading to an appropriate collection and discharge point. Crawlspaces should be sloped to drain, and a positive connection should be made into the foundation drainage sysh�r�, For slabs-on-grade, a drainage path should be provided from Ihe capillary break material �o il footing drain system. Roof drains shoutd not be connected to wall or footing drains Our expenence with gently-sloping glacial dnft sites is that ihe volume o( water collected h; residence foundation drains and routed to the stormwater detention system is ins�gnrficant when considered in the storm drainage design. We do not expect that the foundation drain water will impact the design of the srormwater detention system. Utilities Our exploiations indicate that deep dewatering will not be needed to install standard depth utilities. Anticipated groundwater is expected to be handled wrth pumps in the trenches. We also expect that some groundwater seepage may develop during and fotlowing the wetter Robinson Noble, Inc