Call 415-457-5658 for a prompt, reliable estimate from our experienced estimator. RWR has been doing foundation, excavation, and drilling work in Tiburon and Belvedere in Marin County. You may see our trucks and equipment politely serving neighbors near Trestle Glen, Lyford Drive, and Tiburon Blvd. We’ve been helping repair foundations, slides, and retaining walls in Marin County for over 24 years.

Here’s the kind of detailed estimate you can rely on, to correct foundation problems and perform structural work, land stabilization, retaining walls, and garage additions.

This is an estimate for replacing a failing wood retaining wall and fence. To prepare this estimate certain assumptions were utilized using standard construction practices and design details. Final price is subject to receipt and review of plans completed by a licensed engineer. An allowance has been provided for plans. Cost of permit is additional. The scope of work includes demo of the existing fence and wall, drilling pier holes, installing concrete in piers with steel I beams, lagging, drainage behind the wall and a redwood fence. Our price includes all labor and material to complete the work as per the itemized Scope of Work below.

Scope of Work

Mobilization and Layout
• Coordinate the preparation of plans with engineer (See Engineering allowance) for permit purposes
• Pull building permit as required (cost of permit is additional)
• Mobilize to jobsite with necessary equipment.
• Grub vegetation as required to install new wall
• Daily Cleanup
• Final Cleanup

Demo and Cut Bench
• Demo existing retaining wall, fence and off haul debris from site.
• Cut bench as necessary to install new wall and drainage per plans and specifications.
• Off haul dirt spoils from site

Piers

• Drill twenty four (24) 16” diameter x 6 ft deep holes with drilling equipment. See hard rock drilling conditions. Final depth to be determined by engineer.
• Install twenty four (24) steel I beams (w8x15) x 6 ft deep in pier holes with concrete (minimum 2500 PSI) per plans and specifications. Coat I beams with two part epoxy for protection.
• Off haul pier spoils from site.

Retaining Wall
• Install 3 X 12 pressure treated lumber approximately 136 linear ft x a maximum of 3 ft high per plans and specifications. Treat cut ends with copper green.
• Allow ¼ inch gap between lagging for drainage

Drainage
• Install approximately 12 cubic yds of drain rock 1 ft wide behind retaining wall 1 ft from top of grade.
• Install approximately 136 linear ft of perforated SDR 35 pipe wrapped in filter fabric and exit at end of wall.

Compaction
• Install a native soil cap on top of drain rock approximately 1 ft in depth and compact.

Fence
• Install a redwood fence (construction grade) on top of retaining wall a maximum of 5 ft high approximately 136 linear ft.
• Fence is to be constructed using 4×4 posts with 2×4 framing and 1×8 fencing material
• Include approximately 35 additional ft of fence on the side with 4×4 posts approximately 3 ft deep
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
• Price includes allowance for engineer and plans. Contractor to engage engineer and coordinate all design requirements with engineer to obtain plans for permit. It will require contract to be executed with owner.
• Final price is contingent on receipt of plans and confirmation of assumptions used for estimate.
Exclusions
• 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 work on utilities including buried pipes or irrigation pipes.
• Replacement of damaged landscaping.
• Embedments into concrete other than foundation bolts.
• Excavation and off hauling of hazardous materials, underground tanks, or materials unacceptable at dumps.
• Structural or Earth Shoring
• Additional drainage not specifically outlined in this proposal.
• Importation of backfill material except as noted.
• Damage to trees or cost of arborist
• Cost of surveyor if required