Foundation services
French drain installation: what it fixes outside
French drain installation means burying a perforated pipe in a gravel-filled trench so groundwater and surface water flow away to an outlet.
Find a Foundation Professional What it costs
Written by HyreFoundation Research Desk Primary-source research and fact checking
The short answer
French drain installation means burying a perforated pipe in a gravel-filled trench so groundwater and surface water flow away to an outlet. Around a house, a French drain in the yard intercepts water headed for the foundation.
It works only with steady fall to a legal outlet, and it is not the same as the footing drain the code requires at the base of the wall.
Key takeaways
Daylight, a dry well or an approved system.
One intercepts water upslope; the other sits beside the footing.
A clogged drain is a buried gravel trench.
How is a French drain installed?
The trench runs across the path water takes toward the house and falls steadily to an outlet that does not flood a neighbor.
The trench is lined with filter fabric to keep soil out of the gravel.
Washed stone, a perforated pipe with holes placed as the maker specifies, more stone, then fabric folded over.
Topsoil or decorative stone on top, then a hose test to confirm flow at the outlet.
What moves the price
Length and outlet drive the job. We publish no price figures until we hold enough sourced, dated quotes; see what drives foundation costs.
| Factor | Why it changes the number |
|---|---|
| Length and depth | Longer, deeper trenches mean more digging and stone. |
| Outlet | Daylight on a sloped lot is simple. A flat lot may need a dry well or pump. |
| Obstacles | Roots, rock, utilities and hardscape along the route. |
HyreFoundation publishes no national average price for this work. Depth to bearing, soil, access and method vary enough between two houses on the same street that a single figure would mislead.
Is a French drain the right fix?
It is right when water moves across or through the yard toward the house. It is the wrong first step when roof water from short downspouts is the cause; fix those first. If water enters at the footing level from all sides, look at an interior drain or exterior footing drains instead.
What to ask before you sign
The full checklist is on choosing a foundation contractor.
Where this goes wrong
A trench with no exit fills and stays full.
Roof water can overwhelm a French drain and bring debris. Use a solid pipe for downspouts.
Water collected right at the foundation is in the wrong place unless it is a designed footing drain.
Get connected
Tell us about the work
Three short steps: the job, your home, and how to reach you. Nothing goes to a foundation company unless you agree.
A straight answer first. A person reads it and replies by email, free and with no obligation. Matching is not live yet, so this is not a quote. If a wall is moving or a door frame has racked out of square this week, call a structural engineer first.
Find a Foundation Professional
A person at HyreFoundation reads the request and replies. Matching is not live yet, so this is not a quote.
Questions
What is the difference between a French drain and drain tile?
How deep should a French drain be?
Can I install a French drain myself?
How long do French drains last?
Written and audited by
HyreFoundation Research Desk
Primary-source research and fact checking
We read the model building code, the federal soil and moisture guidance and the insurer position ourselves, and we publish each figure with the document it came from and the date we retrieved it.
Where a number cannot be traced to a primary source, we say so instead of printing it. HyreFoundation does not inspect, engineer or repair foundations. Authorship is organizational: this desk, not a named persona.
- 40
- pages published on this site
- 12
- free tools, each showing its assumptions
- 0
- foundation repairs we perform or sell
- 0
- paid placements or rankings
How this desk works
- Primary sources only. Code statements come from the International Residential Code, Chapter 4, as the model code. Soil statements come from USDA and USGS. Insurance statements come from the policy language and the Insurance Information Institute. We open the source rather than cite a blog that cites it.
- The code is a model, and adoption is local. Your jurisdiction adopts an edition and amends it, and foundation chapters are amended more than most because frost depth and soil are local facts. Every code figure says so.
- We hold no job data. We have no dataset of bids, pier counts or invoices, so no page claims an average from one. Calculators show the arithmetic and the inputs they assumed, and label the result as an estimate.
- We do not diagnose your house. A crack guide can tell you which pattern to measure and when to call a structural engineer. It cannot tell you whether your foundation is failing. An engineer on site does that work.
- We do not repair foundations, and we take no payment for placement, ranking or a favorable mention. Nobody buys a position on this site.
Authorship on this site is organizational: the analysis belongs to the desk rather than to a named individual, and we do not publish credentials we do not hold. Our editorial policy sets out how we source, date and correct what we publish.
Sources & retrieval dates
Information on this page is general and varies with soil, climate, foundation type, building code, insurance policy and circumstance.
It is not engineering, insurance or legal advice, and no page can tell you whether your house has a structural problem: that needs a licensed professional on site.
HyreFoundation is an independent foundation resource, not a repair contractor or an engineering firm, and does not perform, supervise or warrant foundation work.