A gravel trench
We dig a trench along the path of the water and fill it with gravel, giving the water an easy route to flow into instead of pooling.
Bay Area French Drain Installation · Licensed · 13+ Years
French Drain Installation in the San Francisco Bay Area
Water that collects against your foundation is what cracks it, floods your crawl space, and breeds mold. A french drain intercepts that water and carries it safely away — before it does the damage.
Free inspectionLicensed (CSLB #1022608)Foundation & crawl-space drainage13+ years experience
Free on-site estimate · No pressure · We come to you
Why It Matters
Move Water Away Before
It Reaches Your Foundation
The Bay Area's wet winters and clay-heavy soil hold water — and clay doesn't drain well, so that water pools against foundations and seeps into crawl spaces and basements. Once it's there, it's relentless: it works into foundation cracks, floods the space under your home, and feeds the moisture that leads to mold, wood rot, and pests.
A french drain is a simple, proven fix: a gravel-filled trench with a perforated pipe that collects the water and channels it to a safe outlet, well away from the house. It's often paired with a sump pump to pump the water out where gravity can't, and it's the first step to drying out a crawl space that keeps taking on water.
- Keeps water away from your foundation
- Stops crawl space and basement flooding
- Prevents pooling in the yard and against the house
- Protects against cracks, rot, and mold
- Reduces damp, musty air in the home
- Pairs with a sump pump for full drainage
How It Works
How a French Drain
Protects Your Home
It's a straightforward system — but where it goes and how it's built determine whether it actually keeps you dry.
A perforated pipe
A perforated pipe set in the gravel collects the water that filters in and carries it away from the foundation.
Filter fabric
Fabric wraps the system to keep soil and silt from clogging the pipe, so the drain keeps flowing for the long term.
A safe discharge point
The pipe routes the water to a safe outlet — daylight, a drain, or a sump pit — well away from the house where it can't seep back.
Interior or exterior
We install exterior drains to intercept water in the yard, or interior perimeter drains inside a crawl space or basement — whichever fits.
Works with a sump pump
Where the water can't drain by gravity, the drain feeds a sump pit and the pump lifts it out — a complete drainage system.
Do You Need One?
Signs Your Home
Needs a French Drain
Drainage problems show up as water where it shouldn't be — and as damage that follows. Watch for these.
Water pooling near the house
Puddles that linger against the foundation or in low spots of the yard after rain mean water isn't draining away as it should.
A wet or flooded crawl space
Standing water or persistent dampness under the house is a clear sign you need to intercept and redirect that water.
Foundation cracks or settling
Water working against the foundation causes cracks and settling over time — a drainage issue worth addressing early.
Damp, musty odors
A musty smell rising into the house usually means moisture is collecting under or beside it and feeding mold.
Water stains on foundation walls
Stains or white mineral crust on basement or foundation walls show water has been coming through.
Soggy ground after every rain
Ground that stays saturated long after a storm — especially on a slope draining toward the house — calls for a drain.
How We Work
Our French Drain Installation Process
A french drain only works if it's placed where the water actually goes — which is why we start with an inspection, not a shovel.
Free inspection
We inspect your property, crawl space, and grading to trace where the water comes from and how it flows, so the drain goes exactly where it's needed.
Plan the route & outlet
We plan the trench path and a safe discharge point — to daylight, a drain, or a sump pit — that carries the water well away from the house.
Dig & lay the drain
We dig the trench to the right depth and slope, wrap it in filter fabric, and set gravel and a perforated pipe for reliable flow.
Connect drainage if needed
Where gravity won't do it, we tie the drain into a sump pump so the collected water is pumped out and away.
Backfill, test & clean up
We backfill, confirm the water flows to the outlet as intended, and leave the site clean.
Free inspectionLicensed (CSLB #1022608)Drainage traced & done right
Why Attic Pros
The Bay Area's Trusted
Drainage & Waterproofing Team
For over 13 years, Bay Area homeowners and businesses have trusted us to solve their water problems — because we trace the water to its source, install the drainage that actually fixes it, and stand behind the work.
- Licensed contractor (CSLB Lic. #1022608)
- SPCB-registered for pest-related work (Co. Reg. #9901)
- Diamond Certified & Angi Super Service Award winner
- Independently reviewed — verified Google ratings
- Free, no-obligation on-site inspection
- Local team with 13+ years under Bay Area homes
Real Customers, Real Results
Trusted by Bay Area Homeowners
4.8
★★★★★
Based on 1,900+ verified Google reviews — trusted for drainage, waterproofing & home services across the Bay Area
Google Review
★★★★★
Saed Abdullah was here today did a excellent service Thank you again for your help
Steve
Google Review
★★★★★
I appreciate the great communication and flexibility. Samim arrived on time and an appointment went well.
G B
Google Review
★★★★★
I'm very impressed with AtticPros' expediency in scheduling a service call. Samim was courteous, well prepared and knowledgable. He quickly provided a thorough assessment of the situation. What really impressed me is how respectful of the (access through the bathroom) area he was. He cleaned up the attic access door and the (little) fallen insulation on the floor. I highly recommend attic pros for rodent extermination and clean up or any other service required.
Lorna Edits
Google Review
★★★★★
Rodent intrusion and the associated damage they cause is the worst! After reading reviews, I decided on Attic Pros because they have great reviews and because they specialize in the work I needed. I was not disappointed. Within a few days of reaching out, Tom came out and did the estimate. The work began only two business days later! The work was scheduled over two days but they did it all in one! The guys arrived on time and were cheerful, polite, and pleasant to deal with. Kevin showed me pictures and video periodically throughout the day so I could see the work, start to finish. He answered all of my questions and explained everything clearly and patiently. Before they left they made sure there was no trash or debris left behind. The crawl space now looks like it belongs under a brand new home, it’s that clean and tidy. I highly recommend Attic Pros for all of your insulation and rodent elimination needs. Update: I came back and edited this, removing a star. The work and workers were great. However, a few days after the job, Julian from their business office messaged me that they had not received payment and the invoice was past due, even though they were paid IN FULL THE DAY OF WORK. Proof of payment was provided and he messaged me that a receipt would be sent when the payment was deposited. Very disappointing and unprofessional of him to go after a customer for payment when the problem lies with their accounts receivable. 10/14/26 I am adding to my review because issues had been discovered over time. They had missed a place where rats were entering, even though they had been out twice to check traps and found some. This guy did a less than thorough cleaning but he did close off the previously missed access point. My rat intrusion problem has been ongoing. 11/6/26 Attic Pros followed through and sent out Raul, an excellent worker, who took care of everything and made it right. While it may have been problematic for a bit, they kept working until it was all made right. They have been kind and communicative, specifically Paula. I will be calling them again in the Spring to work on a different area of my home.
C Hensley
Google Review
★★★★★
Samim very professional
Rick Weiss
Google Review
★★★★★
Did crawl space cleanup and rodent proofing. They were very efficient and thorough.
James Feichtl
QUESTIONS, ANSWERED
Frequently Asked Questions
Straight answers to the questions people actually ask about french drains — what they are, interior vs. exterior, and how they work with a sump pump. Still unsure? Our team is happy to help.
Still have questions?
Talk to our team — we're here to help.
(800) 543-0382It's a gravel-filled trench with a perforated pipe running through it. Water flows into the gravel, filters into the pipe, and the pipe carries it to a safe outlet away from your home. It's one of the most proven ways to redirect groundwater and surface water so it stops collecting against your foundation.
It depends on where the water is and how it's getting in. An exterior drain intercepts water in the yard before it reaches the house; an interior perimeter drain runs inside a crawl space or basement to catch water that's already coming through and route it to a sump. We determine the right one during the inspection.
Yes — they're a natural pair. The french drain collects and channels the water, and where it can't flow away by gravity, it feeds a sump pit and the pump lifts it out. For homes with a real water problem, the two together make a complete drainage system.
In most cases, yes — if water intrusion is the cause. By intercepting the water and carrying it away, a french drain stops the source of the dampness. When the space has already been damaged, it's often paired with crawl space cleaning and insulation removal to restore it.
Depth and placement depend on where the water flows and the layout of your property — that's exactly what we map during the inspection. The goal is to set the trench along the water's path at the right depth and slope so it drains reliably to a safe outlet.
A properly installed french drain — with filter fabric to keep silt out and the right slope — lasts for many years. The main enemies are clogging and poor drainage design, both of which come down to how it's built, which is why the installation matters.
It depends on the length of the run, access, and whether a sump pump is tied in. Many residential french drains are completed in a single visit or two. We'll give you a clear timeline with your estimate after the inspection.
Very little when it's built right. Keeping the discharge outlet clear and making sure surface water and downspouts aren't overwhelming it is about all it needs. We'll point out anything specific to your setup at the walkthrough.
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French Drain Installation Across the Bay Area
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Ready when you are
Book Your Free Drainage Inspection
Tell us where you're seeing water — pooling, a wet crawl space, damp walls — and we'll trace it, recommend the right french drain, and give you a clear, no-pressure estimate.