Report of Geotechnical Investigation

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� � buildin wall backfill. in these 9 cases, addi�onal fill must be placed m subsided areas to restore � proper su�face drainage away from the building walls to minimize bulk water from ponding against building walls and migrating to the building foundation. ( Waterproofing must be installed along the building's exterior to prevent bulk water from migrating � into the building. Waterproofing and clean free-draining granular material along building exterior surfaces prevents hydrostatic water pressure build-up around these surfaces. Without this � prevention, hydrostatic pressure can [1] force water through cracks and voids in the building's exterior surface and [2] cause buoyant uplift of the building or adverse building wall displacement. ICapillary forces can move soil moisture (water wicking) through the building's exterior into the building; this movement must be blocked. Pores in a foundation wall absorb ground moisture and � release it inside the building as water vapor or in extreme cases as liquid water. Architectural � design must provide capillary breaks to prevent this moisture movement into the building. Consideration should be given to sealing the footing tops with polyethylene, polymer-enhanced asphalt, or other spray- or brush-applied masonry sealants. A capillary b�eak should be installed directly beneath ground floors. The capillary break typically consists of 6 or mo�e inches of clean free-draining uniform granular aggregate underlying the floor sfabs. 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 siabs. The seams of this bamer must be fully sealed with proper sealant to make the barrier watertight. Place a layer of clean free-draining sand 6 inches thick directly beneath the vapor barrier and floor slab. . A good quality building waterproof system includes waterproofing sealant coated onto exterior surfaces of the concrete building wall together with 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 footprinYs perimeter, but they•may be added beneath the footprint upon consideration of proper drain-line design. SubsurFace drain-lines intercept ground water along the perimeter of the building's footprint and possibly beneath it This prevents ground water from migrating into the building by permanentiy lowering the ground water surface to the drain line . elevation. Drain lines 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 storm water drains. Drain lines and discharge points must be properly designed to drain reliably the anticipated ground water quantities that would otherwise migrate into the buiiding. The anticipated quantities may vary with respect to ground water level changes, soil character, and drain-line spacing. The drain- line system designer must apply a proper safety factor against failure of the system to discharge the anticipated quantities. Allied Project 05039 15 July 31, 2005