Underpinning is the extension of the existing foundation down to competent bearing material, which is material that will support the weight of the house and foundation without settling. Techniques include installing reinforced concrete piers, driven steel piles or push piles, hand-dug pits, helical anchors or self-drilling anchors.
Underpinning helps stabilize the foundation, and is often necessary as first step to a major home remodel.
Underpinning is often an excellent solution to level floors, stop the foundation from moving, lift the home close to it’s orginal position, and greatly increase the value of your home.
RWR uses portable equipment during installation, with minimal disruption to your home and surrounding area.
Schedule a free inspection with one of our professional consultants, and get our recommendations for your situation.
Here is an example estimate from RWR, so you can get an idea of the detail and professionalism you can expect from our team of specialists.
This estimate is based on structural plans prepared by Structural Engineer. The bid is for the installation of drilled cast-in-place reinforced concrete piers to stabilize the downhill side of the house as per plans.
Our price includes all labor and material to complete the job as per the itemized Scope of Work below.
Scope of Work
• Mobilize to site.
• Install a temporary chute for spoils off-hauling.
• Demolish and remove from site an existing wooden and concrete pathway as per plans. Remove debris from site.
• Drill and install (7) 18” diameter x 14 ft. deep maximum reinforced concrete piers along downhill side of house and to the northern side of the house foundation as per plans. Sequential installation is required. Off-haul spoils from site.
• Excavate for and install (4) 2 ft. wide x 4.5 ft. long x 1.5 ft. deep and (3) 2ft. wide x 3 ft. long x 1.5 ft. deep reinforced concrete pier caps under existing foundation that are connected to the top of the piers as per plans.
• Repair (4) existing foundation cracks with Simpson epoxy ETI-GV-22 injection as per manufacturers recommendations prior to exterior foundation work.
• Temporarily shore the northern house entry to replace the existing inadequate isolated support with a new reinforced concrete grade beam as per detail 6/S1. Includes a new section of framing cripple wall to tie to new upper structure as per plans.
• Excavate and install approx. 43 linear ft. of reinforced concrete grade beam along the exterior of the existing house foundation and a new walkway perimeter 6” thick concrete stem wall as per plans. Includes approx. (38) reinforced epoxy dowels to tie new to existing foundation and weep holes thru new foundation for water seepage as per plans.
• Backfill walkway area with ¾ crushed rock as per detail 3/S1 to cover a minimum of 4” over new underpinning haunches.
• Install drainage lines as per plans and a new drainage dissipator a maximum of 2 ft. wide x 3.5 ft. long x 2 ft. deep (detail not provided).
• Clean up site and remove construction debris from site.
Notes
• Homeowner’s permission to park drilling power pack at the exiting garage approach/entry for the duration of the drilling procedures is necessary.
Qualifications and Clarifications
• Job is bid as package unless agreement to otherwise
• Includes one mobilization only.
• Prices are subject to adequate supply of rock, concrete, asphalt, PVC resins, PVC pipe, fittings at prices quoted at bid time and are good for 30 days.
• Proposal is based on working std 40 hours per week, 5 work days and mutually agreeable schedules.
• Progress payments every two weeks.
Unit Prices
• Additional footage for drilled and installed piers
Exclusions
• Cost of plans, permits, bonds, testing and inspections.
• Increased costs of excavation or drilling due to hard rock, underground water or caving soils. (Hard rock drilling is defined as a penetration rate slower than 1ft. in 5 minutes). (Hard rock excavation is defined as material that requires the use of a pneumatic or hydraulic breaker to excavate).
• Any work on utilities including buried pipes.
• Removal of spoils from site not mentioned above.
• Structural/Earth shoring.
• Repair to landscaping or irrigation.
• Excavation of hazardous materials, underground tanks, or materials unacceptable at dumps.
