Week 12 · March

Install a French drain

A French drain is a gravel-filled trench with a perforated pipe that collects groundwater and moves it away from the house. It fixes soggy yards, water against foundations and wet crawlspaces.

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Week 12MarchTime: 1 to 3 daysSkill: Moderate to hard

Photo: our crew

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How to do it

Step by step

Call 811 (DigAlert) two working days before you dig.
Lay out the route from the wet area to a lower outlet. Plan at least 1 in of fall per 8 to 10 ft.
Dig the trench. Check slope with a string line as you go.
Line the trench with filter fabric, leaving extra to wrap over the top.
Add 2 in of rock, lay the pipe holes down, cover with rock to 3 in below grade.
Fold the fabric over, top with soil or decorative rock, and install the emitter at the outlet.

When to call a pro: Slopes, retaining walls, water under the slab or drainage onto a neighbor: get an engineer or licensed contractor. It is illegal to redirect drainage onto a neighbor's property.

Rain and flooding guides

Guide

What you need to know

Does your yard need one?

Standing water 24 hours after rain
Water stains or efflorescence on the foundation
Damp crawlspace or musty smell
Downspouts with nowhere to go

French drain vs. other fixes

Grading: cheapest, fix first if soil slopes toward the house.
Downspout extensions: cheap, handles roof water.
French drain: groundwater and surface water across a yard.
Sump pump: when there is no lower place to drain to.

Need help?

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Short on time, or the job needs a license? Tell us the project and the property address area. We will connect you with a licensed local partner and get you a written estimate.

Jobs that require a contractor's license under California law are referred to CSLB-licensed contractors. Check any license at cslb.ca.gov.

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Next projects

‹ Week 11: Clean gutters and extend downspoutsFull 52-week scheduleEvery project by month Week 13: Change HVAC filters and prep the AC ›

Broker, not a contractor. David Thomas Mejia is a California real estate broker (CA DRE #01448424), not a licensed contractor. Work that needs a California contractor's license should be done by a CSLB-licensed contractor; check any license at cslb.ca.gov. Cost ranges on this page are general estimates, not bids.