Looking for a reputable contractor experienced in Wall repairs to provide an estimate in the Corte Madera area? RWR Construction provides expertise in stabilizing land and increasing support of existing foundations as well as new foundations. Techniques include installing reinforced concrete piers, driven steel piles or push piles, hand-dug pits, helical anchors or self-drilling anchors. Contact us today for recommendations and a prompt, professional estimate. We’ve been doing underpinning locally for homeowners, contractors, and engineers for over 30 years.

Call us for a detailed estimate. Here’s an example:

Revised Preliminary Estimate for House & Landscaping Excavation, Pier Drilling, Foundation, Drainage & Waterproofing Work.

This revised preliminary estimate is based on architectural drawings and structural drawings provided. The revised preliminary estimate is for the installation of a new house foundation and pier system as shown on the structural drawings plus landscaping structural concrete per layout on L1.1.
The price includes all labor and material to complete the work as per the itemized Scope of Work below. Price is subject to final structural drawings.

House & Garage Foundations Scope of Work
Mobilization and Supervision
• Mobilize to job site, supervision and final clean-up.

Hard & Soft Demolition + Off-haul
• Demolish existing house structure plus house foundation demolition as per plans.
• Includes demolition of all existing concrete and rock retaining walls, wooden decks, concrete stairs plus house chimney all as shown on A1.9 and outlined on the current drawings for the installation of the new structures except for the existing garden shed (to be use by general contractor as office).
• Remove all soft and hard demolition debris from site.
Demolition exclusions: Permits, retention, hazardous materials abatement & utility safe-offs.

Grubbing and Earthwork
• Grubb and clear the existing small vegetation for the installation of the new house foundation as shown on drawings. Off-haul debris from site. (Trees & stump removal is excluded).
• Excavate (2) level bench/pads per elevations shown on architectural drawings. Stockpile native soil for backfill and re-compaction operations behind the new concrete retaining walls on site.
• Off-haul a maximum of 900 trucked cubic yards of clean native soil from site.
• Perform limited backfill and re-compaction operations with native soils behind the new concrete retaining walls to cap the new drainage system as needed. Re-grade at access ramp area with native soils (behind new garage). No import is included.

60 ft. long x 5 ft. tall I-beams and lagging retaining wall
• Drill (11) 18” diameter x 13 ft. deep piers and install (11) new W8x28x18 ft. long metal I-beams in pier holes. Fill piers with 2500 psi concrete.
• Remove drilling spoils from site.
• Install 3×12 ACZA pressure treated lagging between I-beams. Seal all cut ends with preservative. Leave ¼” gap between boards for drainage.
• Install back drain consisting of permeable class II drain rock as shown on drawings.

Pier drilling and installation
• Drill and install a total of (8) 18” diameter x 10 ft. deep maximum reinforced concrete piers per structural detail 11/S6. See drilling conditions and exclusions below. Final depths to be determined by soils engineer.
• Off haul pier spoils from site.

Install new concrete foundation per sheet S2 & S3
• Install new reinforced concrete house foundation per layout provided on structural sheets S2 & S3. No architectural finishes are included. Standard cast in place is included for the installation of the new foundation retaining walls.

Drainage and Waterproofing
• Behind the new foundation retaining walls, install Paraseal waterproofing membrane and Miradrain 6000 drainage panels over Paraseal waterproofing. Terminate drainage panels into a perforated 4” SDR 35 drainage pipe at base of the new foundation footings. Backfill behind foundation with a 1 ft. thick drain rock pocket wrapped in filter fabric, extending up to 1.5 ft. below new house perimeter sub-grades. (Alternate; use class 2 permeable without filter fabric). Outlet drainage pipe via a buried 4” diameter SDR 35 tite line ending approx. 3 ft. away from the lowest drainage point of the new garage and house foundations.
• Backfill the upper one ft. behind walls and any safety or access drainage cuts in compacted lifts with native soils.

Landscaping Concrete & Drainage Scope of Work
Landscaping Footings Excavation
• Excavate (2) level bench/pads to elevations shown on architectural drawings. Stockpile native soil for backfill and re-compaction operations.
• Off-haul an additional 50 trucked cubic yards (allowance amount) of clean native soil from site.
• Perform limited backfill and re-compaction operations with stockpiled native soils, behind the new landscaping concrete retaining walls to cap drainage system.

Landscaping concrete work per layout on sheet L1.1
• Install reinforced concrete paving slabs at three house patios.
• Install garage street approach/entry pavers.
• Install main entry reinforced concrete stairs.
• Install poured in place concrete pavers: (24/18”x18” + 14/20”x20” + 1/30” x30” +4/96”x24” +5/66”x24”) as per layout on L1.1. Includes color allowance at $30.00 per cubic yard.
• Install new landscaping reinforced concrete footings and 2×6 board formed walls. Includes $30.00 per cubic yard allowance for concrete color for all landscaping walls.

Landscaping Drainage Work
• Install (15) new Christy VO1 drain boxes with grate per C1 layout.
• Install (12) house downspouts per layout on C1.
• Excavate for and install (1) 15 ft. long x 12” wide x 24” deep leach field per detail 3/C2 with two “pop-ups” per 2/C2.
• Install a 18” wide x 6” thick rock filtration trench behind the new I-beam retaining wall per A/C2.
• Install approx. 280 linear ft. of new SDR-35 tite line to outlet house and landscaping drainage as per C1.
• Behind the new landscaping retaining walls, install Miradrain 6000 drainage panels. Terminate drainage panels into a perforated 4” SDR 35 drainage pipe at base of the new landscaping footings. Backfill behind foundation with a 1 ft. thick drain rock pocket wrapped in filter fabric, extending up to 1.5 ft. below new house perimeter sub-grades. (Alternate; use class 2 permeable without filter fabric).
• Backfill the upper 1.5 ft. behind landscaping wall drainage pockets with native soils.

Qualifications
• Job is bid as a package.
• Includes one mobilization only.
• Elevations and layout to be provided by general contractor. RWR will assist general contractor with layout and elevations.
• RWR is not responsible for survey lines. Survey of property lines must be done by licensed surveyor.
• Progress payments every two weeks. No retention.
• Contaminated soil not accepted as clean soil at the dump will incur an additional cost depending on the material. Add $20.00 per cubic yard of rock/shale material off-hauling from site.

Exclusions
• Cost of plans, permits, bonds, testing and inspections.
• Increased costs of excavation or drilling due to hard rock, tree roots, caving conditions, underground water. (Hard rock excavation is defined as material that requires the use of pneumatically, hydraulically or 35 pound and over electrically operated hammers or rams to excavate.) (Hard rock drilling is defined as a penetration rate slower than 1 ft. in 5 minutes.)
• Earth shoring.
• Erosion control or site winterization.
• Tree or stump removal.
• Geo-foam installation.
• Excavation of hazardous materials, underground tanks, or materials unacceptable at dumps.
• Architectural concrete or type of special concrete finish product (e.g. board form, color concrete, sealers, etching, etc.).
• Any work on utilities including buried pipes.
• Mock ups.
• Foundation embedments other than foundation “J” bolts.