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 a site visit and structural drawings. The scope of work is for demo, excavation, installation of underpinning piers/haunches, installing dowels and grade beams and foundation drain. Included is an allowance for reinstalling the stair and deck. The price includes all labor and material to complete the work as per the itemized Scope of Work below.
Scope of Work
Mobilization and Layout
• Mobilize to jobsite with necessary equipment to complete job (See qualifications and clarifications)
• Layout underpinning piers per plans and specifications
• Daily Cleanup
• Final Cleanup
Demo and Shore Existing Structure
• Saw cut approximately 18 ft of driveway in front of garage and remove concrete from driveway across front of garage approximately 1 ft out. Where haunch is located remove approximately 2 ft x 2 ft. of additional concrete driveway.
• Demo and remove concrete stairs and deck as required
• Demo and remove concrete wall and pad on North side of house (Spa heater to be removed by others prior to demo of pad).
• Off haul debris from site
• Shore North side deck existing structure to allow for installation of new pier supports using RWR designed shoring method.
Excavation and Off Haul
• Excavate for underpinning haunches per plans and specifications (1/S1, 3/S1 and 4/S1).
• Excavate for installation of tie beam next to foundation per plans and specifications 2/S1.
• Off haul spoils from site.
Concrete Reinforced Piers
• Drill twelve (12) 18” diameter holes x 15 ft maximum with portable drilling equipment per plans and specifications S1. Final depths to be determined by soils engineer. See drilling condition exclusions.
• Install twelve (12) 18” diameter concrete reinforced piers x 15 ft per plans and specifications.
• Off haul pier spoils from site.
Haunches and Tie beams
• Install approximately 80 dowels using Hilti HY 150 two part adhesive anchor system per plans and specifications
• Install rebar and concrete into haunch excavation per plans and specifications 1/S1, 3/S1 and 4/S1.
• Install rebar and concrete into 1 ft x 1 ft tie beam excavation 1/S1, 2/S1, 3/S1 and 4/S1.
• Backfill all exterior concrete work as required by plans and specifications.
Repair Stairs and Side Deck
• Using existing 4×4 posts reinstall existing posts using galvanized CBSQ44 brackets and attach posts per plans and specifications.
• Install new wooden stairway and deck to replace removed concrete stairs in front of house.
Does not include paint or paint labor. Price does not include rebuilding of structural stair support if necessary. Upon removal of concrete stairs engineer will approve structural integrity of stair and deck support. Stairs and deck are over living space. This will require installation of new waterproofing. RWR will engage a subcontractor to install waterproofing prior to installation of new wooden stairs. Price does not include this additional cost of waterproofing or any type of flashing that may be required.
• Trench approximately 50 linear ft in crawl space of house to install foundation drain per plans and specifications.
• Install approximately 50 linear ft of perforated SDR 35 pipe with cleanouts as necessary along foundation per plans and specifications 6/S1.
• Trench is to be a minimum of 12 in wide x 12 in below crawl space grades
• Trench will be lined with filter fabric and filled with ¾ in drain rock.
• Include a tight line to surface drain drop inlet and exit to outside.
• Discharge perforated pipe to tight pipe on the exterior into existing drainage outlet per plans and specifications.
• In lieu of demo concrete stairs and replacing with wood stairs the pier located under the stair way would be relocated to the exterior of the house (This has been approved by the engineer).
• The haunch for detail 4/S1 would be redesigned with larger rebar (subject to calculation and detail provided by engineer).
• Excavation would occur in interior of home. Demo sheetrock in closet for access under stairway.
• Excavate haunch per plans and specifications with spoils removed through downstairs window.
• Repair sheetrock as required (does not include paint).
(Note: Price difference is greater than shown as waterproofing will not be required with alternative)
Qualifications and Clarifications
• Job is bid as package unless agreement to otherwise
• Includes one mobilization only
• Prices are subject to RWR obtaining adequate supply of wood, steel, 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.
• RWR is not responsible for survey lines. Survey of property lines must be done by licensed surveyor.
• Progress payments every two weeks.
• Estimate does not include replacement of landscaping. RWR will remove landscape material as directed by homeowner for future replacement by others.
• Cost of plans, permits, bonds, testing and inspections.
• Increased cost of drilling or excavation due to hard rock, underground water or caving soils. (Hard rock drilling is defined as a penetration rate slower than 1 ft. in 5 minutes.) (Hard rock excavation is defined as material that cannot be excavated with a conventional backhoe or excavator bucket.)
• Any additional work required as a result of utilities including buried pipes or irrigation pipes.
• Replacement of damaged landscaping, driveway or fence.
• Excavation and off hauling of hazardous materials, underground tanks, or materials unacceptable at dumps.
• Any work related to landscaping, fences or gates except as outlined
• Additional drainage not specifically outlined in this proposal.
• Earth shoring
• Winterization erosion control items (to be completed on a Time and Material basis if required)
• Electrical or Plumbing except as outlined in this proposal
• Backfill or Compaction of any soils not outlined in this proposal.
• Importation of backfill material except as noted.
• Survey of property lines
• Landscaping or irrigation