What to Put in a Drainage Warranty

Two Februaries after you set the pipe, the phone rings. Water is standing in the corner of the yard, the homeowner is annoyed, and the second sentence out of their mouth is "you warrantied this."

What happens over the next twenty minutes was decided long before the call. Either there's a page both of you signed that says what you promised and what you didn't, or there isn't. If there isn't, you're now negotiating from memory against somebody who remembers it more favourably than you do.

This post is about writing that page. It's general guidance from a trade perspective, not legal advice — warranty law, implied warranties and statutory minimums vary by state and province, and a contract attorney in your market should read your final wording before you send it on a hundred proposals.

Most warranty fights aren't about your work, they're about what the work was supposed to do

Sort your last ten callbacks into three piles and the pattern shows up fast.

Pile one is your install. Fall you didn't hold, a fabric overlap that let fines in, a coupling that separated, a trench that settled four inches. You own these. They're usually the smallest pile and the easiest conversation, because there's nothing to argue about.

Pile two is a product. A pump motor quits, a basin grate cracks under a mower, a check valve sticks. The manufacturer owns the part. You own the labour to swap it, or you don't, depending on what you wrote.

Pile three is everything else, and it's the biggest pile. The neighbour regraded. The homeowner added a patio and 400 square feet of new impervious area. The outfall got buried under mulch. A wet-season storm dropped three inches in ninety minutes. The water table came up. None of that is your install, and all of it produces a phone call that starts the same way.

The reason pile three turns into an argument is that the homeowner heard "I'll fix your wet yard" and you meant "I'll move roof water from four downspouts to the street." Both of those can be true descriptions of the same job. Only one of them is a promise you can keep. That gap gets closed in the scope language on the proposal, which is the same page that gets signed, and the warranty is the back half of the same sentence.

Write three separate warranties, because the three things fail differently

One paragraph that says "all work guaranteed for two years" is worse than nothing. It's vague enough that the homeowner reads it as a guarantee of a dry yard, and specific enough that you can't argue with it later.

Break it into three promises with three different terms.

Workmanship. This is the one you fully control and the one you should be most generous with. Name what it actually covers so the customer can picture it:

• Pipe fall and alignment — the system drains as installed, no bellies or reverse grade from settlement of your trench
• Joints, couplings and connections holding without separation
• Fabric placement and overlap
• Stone gradation and depth as specified in the scope
• Basin and cleanout set at grade and staying at grade
• Outfall terminating where the proposal said it terminates
• Trench backfill and compaction, excluding normal topsoil settlement in the first 60 days

That list is doing real work. A homeowner who reads it understands you're warranting the installation, not the weather, without you ever having to say "not the weather."

Materials. Don't invent your own term on somebody else's product. Pass through the manufacturer's warranty and warrant your labour to make the claim happen. Something like: pump, basin and grate carry the manufacturer's warranty; for the first twelve months we'll remove, return and reinstall a warranted part at no labour charge; after twelve months the part is covered by the manufacturer and the labour is billed at our service rate.

That's honest, it's cheap for you, and it stops a $400 pump from turning into a free half-day two years out.

Performance. This is the dangerous one, and most contractors handle it by saying nothing — which means the customer fills in the blank themselves. Better to warrant something narrow and measurable than to leave it open.

A performance clause you can actually stand behind names the water. "The system will convey roof water from the four downspouts identified in the scope to the discharge point at the east property line, under normal rainfall." Not "the yard will stay dry." Not "the water problem will be resolved."

If the customer pushes for broader language, that's a scope conversation, not a warranty conversation. Either you widen the scope and the price to catch the other water sources, or you write down that you didn't.

Exclusions belong in a numbered list, written before anything goes wrong

Exclusions read as defensive when you recite them on a callback and as professional when they're printed on the proposal the customer signed. Same words, completely different reception. Put them in front.

The ones worth naming on almost any drainage job:

1. Storms beyond normal rainfall. Name a threshold if your market has a standard one — a 10-year storm event, or an inch per hour — rather than saying "acts of God," which means nothing to a homeowner.
2. Changes to the site after completion. New patios, pools, decks, sheds, regrading, retaining walls, added downspouts, or work by another contractor over or near the line.
3. Off-site changes. A neighbour regrading, a municipal ditch filled in, upstream development. You can't warrant water you don't control the source of.
4. Blocked or buried outfall. If the pop-up gets mulched over or the daylight end silts in, that's maintenance.
5. Missed owner maintenance. If you spec an annual cleanout flush and gutter cleaning, say the warranty depends on it. Then actually tell them how, at handover.
6. Vehicle or equipment traffic over the trench. A truck parked on a shallow line crushes pipe. That's not a workmanship failure.
7. Freeze damage where discharge lines are above frost, planting over the line, root intrusion, and rodent damage to emitters.
8. Groundwater and water table beyond the depth of the installed system.
9. Unmarked private utilities. Locates cover public services. Irrigation, invisible fence, low-voltage lighting and gas lines to a grill are the owner's to identify.
10. Turf and planting restoration beyond a stated window — see below, because this one is worth handling differently.

Restoration deserves its own treatment. Trench settlement is guaranteed, not a defect. Backfill consolidates, topsoil drops, and at 30 to 60 days there's a visible depression on almost every job. Rather than excluding it and eating the phone call, build a return visit into the price: one topsoil top-up and reseed inside 90 days, included. You're going to get called anyway. Scheduling it yourself turns a complaint into a follow-up, and gets you back on the property with a camera while the customer is still in a position to refer you.

Term length is a cost decision, and the cost is smaller than you think

Contractors pick warranty terms by feel — "one year, same as everybody" — when it's an arithmetic question. Work out what a year of coverage actually costs you.

Say you run 40 drainage jobs a year at an average of $9,000. Go back through last year's calendar and count the true warranty callbacks — the ones where you did work and didn't bill. Suppose it's four.

Now price one. A typical callback is a half day for two people, plus a bit of stone, fabric and fittings, plus fuel and a trailer trip:

• Labour: 2 people × 4 hours × $45 loaded hour = $360
• Materials: $120
• Truck, trailer, fuel, machine time: $80
• Total per callback: $560

Four callbacks × $560 = $2,240 a year. Spread across 40 jobs, that's $56 per job — about 0.6% of a $9,000 average ticket. Swap your own numbers in; loaded hourly cost runs roughly $38-$55 in most markets depending on wages, burden and whether you're carrying a machine payment.

At 0.6%, extending workmanship coverage from one year to two is close to free, and it's the cheapest differentiator you have against the cheaper bid. If your number comes out at 4% or 6%, the warranty term isn't your problem — your install detail is, and the fix is upstream in the failure modes that actually cause the callbacks.

You can only run that arithmetic if you're recording callbacks somewhere. Four numbers per job in a notebook is enough — the method in tracking job actuals by hand works the same way for warranty work. ScapesHQ doesn't do this part: we haven't built job costing or job actuals, so the callback tally stays in your spreadsheet for now.

Here's how the pieces typically get termed. These are common ranges, not standards — some states set statutory minimums and some licensing boards have their own rules, so check locally.

One useful rule: your performance term should cover at least one complete wet season. A drainage system installed in August that carries a twelve-month warranty gets tested honestly. One installed in March with the same term expires right before the storms that matter.

The paragraph that turns a callback into a service call

Exclusions tell the customer what isn't covered. They don't tell the customer what you'll do when they call. That's the paragraph that prevents the argument, and most warranties don't have it.

If you have a problem with the system, call us. We'll come out and diagnose it. If the cause is our installation, we fix it at no charge under this warranty. If the cause is something outside the scope of the work we did, we'll show you what we found and give you a price before we do anything. There's a $X diagnostic fee for out-of-scope calls, waived if the problem turns out to be ours.

Three things happen when that's on the signed page. The homeowner stops bracing for a fight before they dial, because you've already told them you're coming. You've established that diagnosis comes before liability — you're not conceding fault by showing up. And you've priced your time for pile three without having to invent a fee on the phone.

Set the diagnostic fee at your real cost of the trip, not a token number. A two-hour round trip plus an hour on site at your loaded rate is the floor.

On the call itself, the sentence that does the most work is the one that delays the verdict: "I'm not going to guess over the phone. I'll be there Thursday morning, I'll dig the cleanout, and I'll tell you exactly what I find." You've committed to showing up without committing to who pays, which is the only honest position before you've looked.

Put the warranty on the proposal, not in a folder handed over at the end

A warranty certificate handed to the customer on completion day is a piece of paper in a kitchen drawer. Two years later neither of you can produce it, and whoever remembers it more confidently wins.

Put the warranty terms on the proposal instead, above the signature. It gets signed with the scope and the price, as one document, which means the exclusions were agreed before any money changed hands rather than disclosed after. It also does sales work on the way through: a contractor who prints ten specific exclusions reads as somebody who has installed a lot of drainage, not somebody hedging.

Then keep the signed version findable. Which document, which revision, on what date, with the signature evidence attached — that's what settles a disagreement two winters later in about ninety seconds. ScapesHQ keeps the signed proposal, the send history and the activity timeline on the client record permanently, which is the part of this that we have built.

One last discipline: version your warranty language and date it. When you tighten the exclusions next spring, the jobs you sold last year are still governed by last year's wording. Knowing which version a customer signed is the difference between a clean answer and a guess.

A note on the legal side

Everything above is trade practice, not legal advice. Implied warranties of workmanlike performance exist in most jurisdictions whether or not you write one, some states limit how far you can disclaim them, statutes of repose vary widely, and consumer protection rules can override what your document says. Home improvement contract requirements differ by state and by dollar threshold.

Draft your terms from this post if it helps, then pay a contract attorney in your state for an hour to read them. On 40 jobs a year at $9,000 each, that hour costs you about 0.2% of one job's revenue and it's the cheapest insurance in the business.

FAQ

How long should a French drain warranty be?

One to three years on workmanship is common for gravity pipe systems in most markets, with materials passed through at the manufacturer's term. Pick your number by counting last year's real warranty callbacks, pricing one at your loaded crew cost, and dividing across your job count — most contractors find the cost of a second year is under 1% of revenue. Make sure the term covers at least one full wet season for the market you work in.

Can I warranty that a yard will stay dry?

Not safely. You can warrant that a defined system moves a defined water source to a defined outfall — roof water from four downspouts to the street, for example. A yard has multiple water sources, and the ones you weren't hired to fix will still put water on the ground and still generate a phone call. Warrant the water you were paid to move, and name it in the scope.

Should I charge for a warranty callback?

Charge a diagnostic fee for calls that turn out to be outside the scope of your work, and waive it when the cause is your installation. Put that rule in the warranty itself so the customer knows it before they dial. Set the fee at your actual cost of the trip — round-trip drive plus an hour on site at your loaded hourly rate.

Does trench settlement count as a warranty defect?

Normal topsoil settlement in the first 30 to 60 days isn't a defect, it's backfill consolidating. Rather than excluding it and absorbing the complaint call anyway, build one topsoil top-up and reseed visit inside 90 days into the price. Pipe that has developed a belly or reverse grade from bad compaction is a different matter and should be covered under workmanship.

Where should the warranty language go — the proposal or a separate certificate?

On the proposal, above the signature. That way the exclusions are agreed before the job starts rather than disclosed after it finishes, and there's one signed document to point to later instead of a certificate in a kitchen drawer. Date and version your warranty language so you know which wording governs which job.

The short version

Split your warranty into three promises with three terms: workmanship on your install, materials passed through at the manufacturer's term, and performance limited to the specific water source you were hired to move. List your exclusions by name on the proposal, above the signature, and add a paragraph saying you'll come diagnose any problem with a fee that's waived if the cause is yours. Set the term by arithmetic — count last year's warranty callbacks, price one at your loaded crew cost, divide across your jobs — and have a contract attorney in your state read the final wording.

Book a walkthrough and we'll look at how your current proposal handles scope, exclusions and the signature that proves what was agreed.