Report of Geotechnical Investigation

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�.vvv v�i t� i�s,cv rna vav�ovo 1tvD1A1V1 1C,J111Vb/ALLl�U (�003 ground water condition near a depth of 13 feet in the Borings). Architectur'al �esidential building design must provide waterproofing and capiilary break protection for the building_ Rain and mel6ng snow are the two main buik water sources that can wet building interiors. A prvperly sized gutter and downspout system will collect water falling on a building's roof and remove the water we(I away from the building to discharge points such as g�ound surfaces or storm water drains. Withouf this system, water will fall from the roof and splash against the building's exposed walls, then drain along iE by gravity down to the building's foundation. This water can saturate, soften, and weaken the foundation's support soil and dampen the basement. Ground surFaces surrounding the building must be graded away from the building using 5 percent minimum slopes to direct storm water away from the building. Waterproofing must be instailed alortg the building's exterior to prevent bulk water from migrating into the building. Waterproofing and clean free-draining granular material along building exterior surtaces prevents hydrostatic water pressure build-up around these surFaces. �thout this pr�:vention, hydrostatic pressure can [1]force water through cracks and voids in the building's e3derior sur�ace and. [2] cause buoyant uplift of the building or adverse building walf displacement. Capillary forces can move soil moisture (water wicking) through 1he building's e�Qerior inta the building; this movement must be blocked. Pores in a foundation wall absorb ground moisture and release it inside the building as waler vapor or in extreme cases as liquid water. Architectural design must provide capillary breaks to prevent this moisture movement into the building_ ConsideraGon should be given to sealing the footing tops wi#h polyethylene, potymer-enhanced asphalt, o�other spray- or bnuh- applied masonry sealants. A capillary break should be instalted direcUy beneath ground floors. The capillary break typically consists of 6 or more inches of clean free-draining uniform granular aggregate underlying ihe floor slabs, Plastic vapor barriEr sheeting with sealed seams should be placed between the slab and aggregate to stop the vapor transfer up into the basement floor. The aggregate breaks capillary movement of ground moisture up into the floor. Based on typical building codes, we recommend placing a polyurethane vapor barrier at least 6 mil thick directly beneath floor slabs. The seams of this barrier must be fulfy sealed with proper sealant to make the barrier watertight. Place a layer of clean ftee-draining sand 6 inches thick directly beneath the vapor barrier and floor slab_ A good quality building waterproof system includes waterproofing sealant coated onto exteriar surfaces of the concrate building wall together wifh clean free-draining granular material that drains ground water to drain lines. Waterproofing membranes must resist water infiltration caused by a maximum anticipated bulk water pressure head. Waterproofing drain-lines must be installed around the building footprint's perimeter, but they may be added beneath the footprint upon consideration of proper dtain- (ine design. Subsurface drain-lines intercept ground water along t�e perimeter of the building's footprint and possibly beneath it_ This prevents ground water from mig�ating into the building by permanenUy Iowering the ground wate�surface to the drain line elevation. Drain lin�s must be below the bottom of the lowest floor slab grades. Drain line water must flow by gravity to discharge points such as automatic sump pumps or slorm water drains. Drain lines and discharge points must be properiy designed to drain reliably the antiapated ground water quantities that would otherwise migrate into the building. The anticipated quantities may vary with respect to ground water level changes, soil character, and drain-line spacing. The drain-line sysiem design�r must apply a proper safety factor against failure of the system to discharge the anticipated quantities. Drain lines should be pertorated or slotted PVC pipes at least 4 inches in diameter. The drain lines should be encased in clean (less lhan 5 percent fines passing #200 sieve) free-draining uniform granular aggregatE fully wrapped in filter fabric to prevent soil from migrating into the drain tile over time_ Aflied 05039 (preliminary feasibility repolt) 2 July 18,2005