Filter Fabric
Separates the collection zone from surrounding soil. Material selection and placement should suit the site and drainage approach.
FRENCH DRAINAGE SYSTEMSCollect Water Below Ground.
Collect Water Below Ground.
Protect the Spaces Above It.
A French drain is an underground collection system. Water enters a gravel-filled trench and perforated piping, then travels along a planned route toward a suitable outlet or collection basin.
The gravel provides a collection zone around the pipe. Filter fabric separates that zone from surrounding soil, helping limit the movement of fine particles into the system. The route and outlet must be considered together with the areas where water is entering.
French drain installation can be part of a broader moisture control plan for a yard, foundation perimeter or below-grade space. It should follow a site assessment rather than simply placing a trench wherever digging is easiest.
Drainage & Moisture Control Inc. serves San Francisco and our established Bay Area locations. We discuss the water concerns, available access and drainage approach before defining the proposed work.
Discuss Your Drainage Concerns
REAL INSTALLATION DETAILCollection starts
with the right placement.
with the right placement.
UNDERSTAND THE SYSTEMFour Components.
Four Components.
One Connected Water Route.
A French drain is more than a pipe in the ground. Collection materials, pipe placement and discharge need to function as a coordinated system.
Drainage Gravel
Creates space around the pipe where water can collect and move. It forms part of the trench assembly rather than a decorative surface layer.
Perforated Pipe
Collects water along the drainage route. Its placement, connections and access need to work with the collection zone and the planned outlet.
Discharge Route
Carries collected water to an appropriate destination. Gravity drainage, solid piping or a sump pump may be needed depending on the property.
Collection vs. transport
A French drain uses perforated pipe to collect water. A solid drain line moves water that has already been collected. Some properties need both.
WHEN TO ASK FOR AN ASSESSMENTRecurring Water.
Recurring Water.
Signs Worth Investigating.
The visible symptom is a starting point, not a diagnosis. Describe where moisture appears and how it changes during rain so the underlying conditions can be reviewed.
Cracks, shifting soil or water entry can have several causes. A French drain is not automatically the answer to every foundation or structural concern.
Read about hydrostatic pressure ↗Pooling Near the Foundation
Water remaining close to a building after rain is a reason to review grading, collection and discharge.
Persistent Soggy Ground
Areas that stay wet longer than the surrounding yard may need an assessment of underground water movement.
Basement Stains or Seepage
Water marks and moisture at walls or floor edges can point to a below-grade water concern.
Musty Below-Grade Spaces
A damp crawlspace or basement deserves a closer look at moisture sources, drainage and ventilation conditions.
A PROPERTY-SPECIFIC APPROACHPlan the Route.
Plan the Route.
Build Around the Site.
French drain installation in the Bay Area needs a clear connection between the water problem and the proposed work. These are the details to discuss before moving forward.
Original company project photography.
- 01
Understand the Water Source
Discuss where water collects, how often it appears and whether the concern is in the yard, near the foundation or inside a below-grade space.
- 02
Review Access & the Route
Consider slopes, existing surfaces, underground services, nearby structures and where collected water can be discharged.
- 03
Define the Installation Scope
Review the proposed trench, collection materials, piping and any related components. Identify the access and surface work included in the estimate.
- 04
Coordinate the Drainage Details
Installation planning should account for connections, transitions, access points and any pump system needed to move collected water.
- 05
Discuss Upkeep
Ask how the system can be checked and which maintenance tasks apply to its collection points, discharge route and connected equipment.
LOOK INSIDE THE WORKInstallation Details.
Installation Details.
Original Project Photos.
Explore nine original photos supplied for this service, distributed throughout the page. The gallery below shows six individual installation details; no project location or before-and-after relationship is assumed.
WHEN YOUR PROPERTY NEEDS MOREFrench Drains.
French Drains.
And the Systems Around Them.
The collection trench is one part of water management. Your property may need related services depending on where water comes from and where it must go.
SAN FRANCISCO & SURROUNDING COMMUNITIESFrench Drain Services
French Drain Services
Across Our Bay Area Locations.
Tell us your address and drainage concerns to discuss project availability. Explore the established area pages below for more local information.
Marin County
San Rafael, Novato, Mill Valley, Tiburon, Corte Madera, Larkspur, Ross, Fairfax, San Anselmo, Greenbrae, Kentfield, Belvedere, Stinson Beach, Inverness, Point Reyes Station, Woodacre, Lagunitas and Forest Knolls.
Explore Marin County services ↗San Mateo County
San Mateo, South San Francisco, Daly City, Redwood City, Millbrae, Burlingame, Belmont, San Carlos, Colma, Brisbane, Portola Valley and Woodside.
Explore San Mateo County services ↗Berkeley
Berkeley Hills, Claremont, Elmwood, Gourmet Ghetto, Ocean View, Thousand Oaks, Cragmont, La Loma Park, Panoramic Hill, LeConte, Lorin/Acton, Poet’s Corner, Southside and the Telegraph, University Avenue and San Pablo Park areas.
Explore Berkeley services ↗Sonoma County
Santa Rosa, Rohnert Park, Sebastopol, Geyserville and Sonoma. Explore the county page for local drainage service information.
Explore Sonoma County services ↗Petaluma
Discuss French drain installation and water concerns at your Petaluma property, including collection, piping and below-grade moisture needs.
Explore Petaluma services ↗PLAN WITH MORE CONFIDENCEFrench Drain Questions.
French Drain Questions.
Practical Answers.
Discuss the details that affect installation scope, discharge and upkeep before choosing a system.
Request an EstimateIs a French drain the same as a surface drain?+
A French drain collects water along a below-ground trench through gravel and perforated pipe. A surface inlet collects water at a defined point. The systems can be combined when both surface runoff and underground moisture need attention.
Can a French drain help with basement water?+
It may be part of the solution when water around or below the property needs to be collected and redirected. Basement leaks can have several sources, so entry points and drainage conditions should be assessed before selecting a system.
How much does French drain installation cost?+
Cost depends on the extent of excavation, access, existing surfaces, collection materials and discharge route. Pumps, additional piping and restoration work can affect the scope. A property-specific estimate is more useful than a single generic price.
Where does the collected water go?+
The outlet must be planned for the property and appropriate local requirements. Depending on the site, collected water may travel through solid piping or enter a sump basin. Do not assume it can discharge onto a neighbor’s property or into any available connection.
Will you need to disturb my yard or walkway?+
Access and excavation requirements depend on the route. Discuss landscaping, paths, existing structures and any surface removal or restoration before agreeing on the work.
Does a French drain eliminate every moisture problem?+
No. Drainage, plumbing leaks, surface runoff and vapor-related moisture are different concerns. A site assessment helps determine whether a French drain is appropriate and whether other work should be considered.
What maintenance should I plan for?+
Keep accessible collection points and outlets clear, and ask how to identify changes in flow. Connected sump pumps have their own upkeep needs. Maintenance recommendations depend on the installed system.
How do I get started?+
Call (415) 226-5888 or (650) 609-0030, or use the estimate form on our Home page once it is connected. Share your location, water concerns and any useful project photos.
LIC#1124677Start With the Water Problem.
Start With the Water Problem.
Let’s Discuss the Right Next Step.
French drain installation and coordinated moisture control for your Bay Area property.