Due to the magnitude of the differential settlement and the vulnerability to future settlement, stabilization and lifting are required as follows: Install helical piles or push piers for the underpinning and lifting of the foundation in the moderate to severe areas. Typically, the helical piles or push piers cost around $2,000 each for installation.
Only licensed foundation stabilization contractors who specialize in this work should be contacted for construction.
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Costs for this solution will be approximately:
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$8,000 helical piles or push piers (if 4 are required)
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$2,000 exterior concrete removal and replacement
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$1,500 plan check & permits
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$2,000 structural engineering
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$2,000 geotechnical engineering
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$1,500 inspection
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$2,000 stucco & drywall repair after lift
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Total Costs: $19,000
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Please note, these are rough order of magnitude estimated costs. Actual costs may vary.
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Special care should be taken to address the drainage issues along the exterior of the home that do not have hardscape (such as the areas with pavers). New concrete slabs should be installed within 5ft of the structure around the entire structure’s perimeter. The new concrete slab to house interface should be properly sealed to prevent water seeping through. New slabs should be sloped away from the structure at 3/8 inch per 12 inch. Linear trench drains and drain lines should be installed at the new slab to soil interface to move collected water off the new slab into the drain. A licensed landscape contractor or licensed landscape architect may be consulted for final design recommendations. Additional roof gutter installation, roof gutter assessment/maintenance, and downspout subterranean drain lines assessment/maintenance, around the perimeter is necessary to avoid large sheet flow water off the roof in proximity of the foundation. Surface topography should be re-graded so as to ensure surface runoff flows away from each side of the house. A new drip irrigation line should be installed under the slab to keep the current moisture content in the soil consistent throughout the seasons.
After the underpinning and lifting is achieved, exterior stucco cracks may be locally repaired by a qualified handyman or licensed contractor specializing in this work. At the exterior repairs to cracked stucco, use either an injected epoxy compound to help prevent water intrusion or remove/replace stucco 6 inches beyond the crack to ensure material continuity (the same welded-wire mesh as existing should be used in the replacement material).
After the underpinning and lifting is achieved, at the roof framing ridge, if rafter members have separated beyond ¼inch from the ridge board, a Simpson Strong Tie connection (such as a LRU26Z, LSU26, THA213, etc.) should be installed to ensure framing member continuity in a gravity or seismic event. Contractor shall take special precautions to ensure the Simpson Strong Tie connection is properly connected so additional pulling of the roof rafter away from the ridge does not occur. Additional strengthening shall include a 2×6 horizontal member to connect at mid-height of the rafters as shown in the sketch below on each side of the roof ridge board.
FOUNDATION ENGINEERING 