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Location

69 Paul Drive
San Rafael CA 94903

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Office hours

Mon – Sat 8:00 AM – 6:00 PM
Sun – Closed

Call us Today

415-785-7522



Location

69 Paul Drive
San Rafael CA 94903



Office hours

Mon – Sat 8:00 AM – 6:00 PM
Sun – Closed

Call us Today

415-785-7522

Call us Today

415-785-7522

Specialized Waterproofing & Leak Repair Mill Valley

Mill Valley sits where the slopes of Mount Tamalpais meet Richardson Bay, so rain pours down from above while high tides press in from below. Low-lying stretches around Tam Junction and Bothin Marsh have a long record of ponding during heavy storms and king tides. As a waterproofing contractor in Mill Valley, I Construction & Structural Inc. follows moisture back to its true entry point, whether that’s a redwood-shingle cabin in Homestead Valley or a garage level just off Miller Avenue.

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Mill Valley Homes Were Shaped by Creeks and Steep Terrain

Drive through Mill Valley, and the building styles shift with every turn: rustic cabins from the early 1900s tucked beneath redwoods, mid-century houses balanced on posts and piers along steep slopes, and compact mixed-use buildings clustered around the downtown plaza. Each type takes on moisture in its own way, and each breaks down in its own way. Our waterproofing services in Mill Valley typically begin once a wet season has exposed the flaw, such as a hillside drainage path that dumps water against a foundation, a lower-level garage seeping at the wall base, or a deck that has soaked up rain for decades with nothing sealing it underneath.

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Our Services

I Construction & Structural Inc. designs every building waterproofing plan in Mill Valley around the property’s actual conditions. A fix that suits a Blithedale Canyon hillside home rarely suits a creekside cottage in Sycamore Park, and neither resembles what a downtown mixed-use building requires, so we sort out which situation a property is really in before building the repair around it, not a generic template.

Balcony, Roof Deck & Parking Deck Waterproofing

Elevated decks and flat-roofed sections are everywhere in Mill Valley, from view balconies on hillside houses to podium-style garages beneath downtown buildings. Many were finished with a thin coating and little thought for runoff, and that coating eventually gave out. Roof waterproofing in Mill Valley on these surfaces generally means stripping the worn layers down to the substrate and installing a system designed to handle both pedestrian use and pooled water.

Removal of failed surfaces and torch-applied membrane installation on decks, roofs, and garages
Flashing and sealing around railings, drains, and wall joints where coatings crack first
Corrective leveling of depressions that trap water rather than move it along
Targeted patching of membrane areas still in good shape, avoiding needless full replacement
Water-holding tests after membrane installation, before the final wearing surface goes on

Concrete Wall & Structural Leak Repairs

Plenty of the concrete seepage we’re called about in Mill Valley originates in older stem walls and garage-level foundations cast before waterproofing layers became routine. When winter rains soak the hillside soil, the lack of any barrier lets moisture creep through steadily. Foundation waterproofing in Mill Valley on walls like these usually means fixing a flaw built in from day one, not just cleaning up after the latest storm.

Digging down beside the affected wall to expose where water passes through
Coating the exterior face with modern waterproofing where none was ever applied
Sealing live cracks so they can’t keep letting moisture into the wall
Adding drain lines that carry groundwater away before it builds against concrete
Returning inside after a heavy downpour to verify the wall stayed dry

Retaining Wall & Basement Waterproofing

Hillside properties throughout Mill Valley, from Cascade Drive to the ridges above Throckmorton Avenue, rely on retaining walls and lower-level rooms that were often built well before today’s drainage standards. Residential waterproofing in Mill Valley hinges on one deceptively simple question: is water being forced through the wall by soil pressure, or is it sheeting across the surface until it finds a gap? The answer determines everything that follows.

Waterproof coating or membrane applied across exterior of retaining and basement walls
French drain installation to relieve the hydrostatic pressure building behind the wall
Grading adjustments that direct surface runoff safely away from the building foundation
Sealing cracks, cold joints, and wall-to-footing transitions to stop water from entering
Sump pump installation on low-lying lots that require a dependable mechanical backup

Our Waterproofing Work in Mill Valley

Hillside Drainage Correction

Runoff from the slope above a redwood-shingle home was funneling straight toward the downhill foundation wall each winter. We installed a curtain drain uphill and sealed the exposed concrete face so the wall stayed dry through the season.

Garage Deck Membrane Replacement

The elevated parking level of a mixed-use building had a coating that was peeling away and letting water drip onto the units below. We removed the old surface, laid a fresh torch-applied membrane, and reshaped the deck so rain flowed to the drains instead of pooling.

Slab Moisture Repair

A single-story home near the bay showed damp patches along interior baseboards after every big storm. Soil outside had settled toward the house, so we rebuilt the grade and buried a perimeter drain to redirect the water.

Why Choose I Construction?

Water Risk Changes From Street to Street

Bayfront pockets near Tam Junction and low ground along Richardson Bay contend with tides, groundwater, and storm surge. Up in the canyons and on the ridges, the concern flips to fast-moving runoff and soil saturation. Pinpointing which of these applies to a property shapes the entire waterproofing strategy before a single tool comes out.

Original Flaws Matter More Than Recent Weather

Many Mill Valley buildings date to an era before membranes and drainage requirements existed, particularly the old cabins converted into year-round homes. So an issue that seems to have appeared this winter is often a water leak repair in Mill Valley that has been developing since construction, made worse by decades of redwood-country dampness.

Creek, Bay, and County Approvals

Digging or drainage work near Old Mill Creek, Arroyo Corte Madera del Presidio, or the Richardson Bay shoreline can require additional sign-off from the city, county flood control agencies, or other regulators. We account for those steps when scheduling a project, so approvals don’t stall the job halfway through.

Noticing Water Where It Doesn't Belong?

Baseboards that stay damp after every rainstorm, a deck surface that feels soft underfoot, or a stain spreading across a ceiling all deserve attention before the next big storm arrives. If you’re comparing options for leak repair in Mill Valley, homeowners tend to reach out once the signs become hard to ignore; send us a few photos of what you’re seeing, and we’ll help you work out the cause.

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Protecting Homes Throughout Mill Valley Communities

I Construction & Structural Inc. serves Mill Valley homeowners with dependable water leak repair and waterproofing solutions matched to each property.

Dominican Hills
Old Mill
Sycamore Park
Tamalpais Park
Miller / Molino
Blithedale Canyon
Cascade Canyon
Scott Valley
Alto
Homestead

Frequently Asked Questions

How can I tell if dampness in my garage or crawl space is a leak or just condensation?

Condensation appears as beads of moisture across a wide area, especially on cool mornings, and fades as air warms. A leak concentrates in one spot, near a crack, joint, or wall base, and worsens after rain. Photos at different times help us tell them apart.

Can redwood roots and heavy tree cover near my foundation cause water problems?

They can contribute. Roots can open gaps in old concrete and clog drain lines, while dense canopy keeps the ground shaded and slow to dry between storms. We check for both during a site visit, since a drain that looks fine may be blocked underground.

Do I need a permit for waterproofing work near a creek in Mill Valley?

Work close to a creek, the bayfront, or a drainage channel can require review beyond a standard building permit. Whether it applies depends on proximity and how much soil is disturbed. We check this early so approvals fit the schedule rather than delay the work.

What happens during a waterproofing inspection?

We look at where water collects, how the ground slopes around the building, and the condition of walls, joints, drains, and decks. Then we trace moisture to its likely entry point. You learn what we found and which repair is needed before any work begins.

How long does a typical waterproofing repair take?

A small sealing or patching job can finish in a day or two, while excavation, drainage installation, or a membrane replacement usually takes longer. Weather, access on steep lots, and permit requirements affect the timeline. We give you a realistic schedule after seeing the site.

Can a sump pump alone fix a wet basement or lower-level room?

A pump removes water that has collected, but it doesn’t stop water from entering. It works best alongside sealing, drainage, and grading that reduce how much water arrives in the first place. On low-lying lots, it serves as a backup rather than the whole solution.

Will waterproofing get rid of the musty smell in my lower level?

Often, yes, once the moisture source is stopped, because that smell usually comes from damp materials and trapped humidity. Existing mold or soaked insulation may still need to be cleaned or replaced. Fixing the water problem first keeps the odor from coming back after cleanup.

Is it better to waterproof a wall from the inside or the outside?

Exterior work is more effective because it blocks water before it reaches the wall. Interior methods can manage dampness when digging isn’t possible, such as against a neighboring structure or a steep slope. We recommend the approach that fits your property’s access and site conditions.

Can waterproofing help a home near Richardson Bay during king tides?

It can reduce how much moisture reaches the structure through sealed walls, drainage, and pumps where needed. Tidal flooding is a broader site condition, though, so waterproofing manages the building’s exposure rather than eliminating the flood risk. We explain what is realistic for your location.

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No Obligation Consultation

No obligation, no pressure, consultation allows you to find out for yourself and decide based on knowledge.

Friendly Crew

We know we are working for you and do our best to make sure you are 100% satisfied with our work.

Safety First

With over two decades of experience we place your safety above all else. All plan and projects take this as first priority.

About us

We are a locally owned and operated company that values honesty and integrity and treats your home as if it were our own. We offer a variety of contracting services customizable to each individual project.

Services

Contact us

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I Construction & Structural Inc
69 Paul Drive
San Rafael CA 94903

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Office: 415-785-7522
Service: 415-424-5969

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Fax: 415-785-7137

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[email protected]