Instagram Reel
Watch the jobsite view
Open the original Reel on Instagram to see current jobsite work.
Open on InstagramThe original post is ready to watch
Sonoma & Napa Counties, CA • Underground & Surface Construction
A Trusted Team To Get The Job Done
Honest, reliable, and efficient underground and surface construction. From precision grading and concrete flatwork to complete utility trenching, stormwater drainage, and septic systems, we build with uncompromising standards.
Call directly:(707) 303-6889
Prompt site review & honest estimates
Comprehensive Site Solutions
Driven By Passion. Delivered With Experience.
We handle tough underground and surface site challenges across Sonoma and Napa Counties. Every job is executed with specialized equipment, skilled operators, and attention to long-term durability.
01
Concrete
Poured Flatwork & Structural Foundations
High-quality concrete work specializing in driveways, sidewalks, building pads, footings, and stem-walls built to exact municipal and structural code requirements.
Driveways & Walkways
Building Pads & Slabs
Footings & Stem-Walls
02
Grading
Slope Optimization & Subgrade Prep
Precision elevation and slope management to optimally divert stormwater runoff, prevent pooling, and prepare compacted grade for durable asphalt or concrete flatwork.
Stormwater Diversion
Subgrade Compaction
Asphalt & Flatwork Base
03
Fire & Water Utilities
Underground Supply & Code Compliance
Comprehensive planning, trenching, and execution of underground supply lines for water and dedicated fire suppression systems for new construction and renovations.
Water Supply Lines
Fire Line Conduits
Utility Trenching
04
Excavation
Site Preparation & Heavy Earthmoving
Complete site prep, deep trenching, hillside clearing, foundation digging, and heavy soil relocation operated with well-maintained equipment and experienced crews.
Site Prep & Clearing
Foundation Digging
Heavy Soil Operations
05
Drainage
Stormwater Management & Protection
Expert drainage solutions that divert heavy stormwater runoff safely away from buildings, foundations, and hillside structures to prevent water damage.
Runoff Redirection
Foundation Protection
Surface & French Drains
06
Septic Systems
Mound, Leach Line & Infiltrators
Wide variety of septic services including engineered mound systems, at-ground installations, leach lines, and infiltrator systems for new construction or full replacements.
Mound & At-Ground Systems
Leach Line Installs
Replacements & Upgrades
Have a unique or multi-phase project?
We coordinate excavation, grading, utilities, and flatwork under one roof so your site moves forward seamlessly.
Proof In The Ground
Completed Work & Job Site Gallery
We let our work speak for itself. Here is a look at our authentic field projects across Sonoma County, including residential flatwork, deep infrastructure trenching, and structural retaining walls.
Surface Flatwork & Paving
Residential Access & Driveway Finish
Precision surface grading and durable asphalt paving with clean transition edges and proper water runoff drainage.
Underground Infrastructure
Deep Utility Trenching & Conduit
Engineered trench excavation, gravel bedding, and multi-line utility conduit installation meeting structural specifications.
Earthmoving & Retaining
Hillside Stabilization & Wall
Heavy machine slope excavation, backfill compaction, and engineered retaining wall assembly for soil retention.
View Completed Work PhotosFive field photos, one dedicated page
From The Jobsite
See What's Moving On Site
Take a closer look at current jobsite work through our Instagram Reel. Watch it here when the official embed is available, or open the original post on Instagram.
Watch On InstagramOriginal Reel • Opens in a new tab
The official Instagram player appears when available. If it cannot load here, the direct link keeps the Reel ready to watch.
The original Reel opens on Instagram in a new tab.
Google Reviews
What Our Clients Say
The finished work matters, and so does the experience of getting there. These selected words come from people who worked with Over & Under Construction on real projects.
Selected excerpts from our Google Business Profile. This section is a hand-selected snapshot, not a live-synced feed. Visit Google for the current rating and full review text.
Selected excerptGoogle
“I’ve had the pleasure of working with Over Under Construction for a few years now and I have to say, they truly stand out from the crowd.”
Selected excerptGoogle
“We worked with Over and Under Construction for multiple projects and they were incredible partners. They were honest, reliable, trustworthy, and did amazing work.”
Selected excerptGoogle
“Over and Under replaced a driveway apron and some sections of sidewalk in an older neighborhood. Their communication and work was highly professional.”
Selected excerptGoogle
“Dylan took charge of the entire process. He was incredibly patient and professional and coordinated with the City, the Fire Department, and everyone else involved to make sure the work was completed properly and met all requirements.”
See the Full Review SnapshotSelected excerpts, with the full profile on Google
About Over & Under Construction Inc.
Reliable Underground & Surface Work Across Sonoma and Napa Counties
Over & Under Construction Inc. offers full-service underground and surface construction services that take the stress off your hands. We take pride in building genuine client relationships rooted in trust, honest assessments, and getting the job done right.
Whether preparing a site for a new building pad, routing heavy storm runoff, digging deep utility trenches, or installing replacement septic systems, our focus on every job is practical, efficient, and professional execution.
Service TerritorySonoma & Napa Counties, CA
Direct Contact(707) 303-6889
Dedicated heavy machinery and hands-on operators for every site demand
Core Standards
Values Applied To Every Project
Our reputation in the field depends on the standards we uphold every single day.
Relationships
Built On CommunicationWe believe successful construction starts with honest conversations. We take the time to understand your goals, answer questions directly, and maintain dependable communication from first estimate to final walkthrough.
Safety
Every Site, Every ShiftConstruction safety is evident in how we operate. From protecting existing underground utilities to managing heavy equipment on challenging terrain, our standards protect crew members, your property, and surrounding structures.
Integrity
Accountable CraftsmanshipWe believe in doing what we say we will do, the first time, every time. Honest job assessments, clear pricing, and reliable execution. Our reputation across Sonoma and Napa Counties is built on standing behind our work.
Estimate & Site Assessment
Get In Touch For Your Free Project Estimate
Submit your project details below. Our team reviews your scope, location, and site requirements, then contacts you to discuss next steps and provide an accurate estimate.
Prefer to talk right now?(707) 303-6889
Call us directly to discuss urgent site repairs, active project timelines, or on-site inspections in Sonoma and Napa Counties.
Serving Sonoma & Napa Counties, CA
We provide full underground and surface construction across Sonoma and Napa Counties for residential properties, general contractors, and commercial sites.
