The Contractor's Guide to Warranties: What to Promise, What to Exclude

The warranty you never defined

A painter completed a full exterior job in spring. Eighteen months later, the homeowner called: the paint on the north-facing wall had faded noticeably compared to the south side.

Was this the painter's fault? Possibly — if the wrong paint was used or the prep was inadequate. Possibly not — if the material degradation was within normal parameters, or if the north wall had a moisture issue behind the siding.

Without defined warranty terms, this conversation becomes a negotiation. The customer's expectation is "it should look good for five years." The contractor's assumption was "I warranted my labour, not the paint's performance over time." Neither expectation was written down.

The cost of this ambiguity is either a free revisit that damages the margin on the original job, or a dispute that damages the customer relationship. A well-written warranty eliminates both outcomes.

---

What a warranty covers vs. what it doesn't

A contractor warranty typically covers workmanship — the quality and correctness of the installation itself. It does not cover:

• Material defects — products that fail are covered by manufacturer warranties, not yours
• Normal wear and tear — surfaces degrade over time; this is expected
• Customer misuse or modification — if the customer painted over your work with incompatible paint, that's not your failure
• Pre-existing conditions — problems that existed before your work began
• Acts of nature — storm damage, flooding, freeze-thaw cycles beyond normal range
• Work done by other parties after your job — if another contractor touched it after you, your warranty is voided

Each of these exclusions is worth stating explicitly in your terms. As discussed in the terms and conditions guide, the goal is not to minimise your responsibility — it's to define it clearly so both parties understand what the warranty actually covers.

---

Workmanship warranty periods by trade

Painting (exterior): 1–2 years on labour; reference the manufacturer's warranty for the paint product itself (often 15–25 years for premium products)

Roofing: 1–2 years workmanship. Manufacturer warranties on shingles are separate (30-year, lifetime, etc.) and are between the customer and the manufacturer. Be explicit about this distinction.

HVAC installation: 1 year workmanship; refer to manufacturer warranty for equipment (typically 5–10 years on parts with registration)

Plumbing: 1 year on labour and parts supplied

Electrical: 1 year on workmanship; manufacturer warranty on fixtures

Concrete/flatwork: 1 year on workmanship; note that cracking from freeze-thaw or ground movement beyond control is excluded

These periods are reasonable starting points. Some contractors offer longer warranties as a competitive differentiator; if you do, make sure the scope is precisely defined.

---

The language that works

"Contractor warrants all workmanship against defects in installation for a period of [12 months] from the date of job completion. This warranty covers defects directly resulting from Contractor's work and does not cover: normal wear and tear, damage resulting from customer misuse or modification, pre-existing conditions, acts of nature, material defects covered by the manufacturer's separate warranty, or work performed by other parties after project completion. To make a warranty claim, contact Contractor in writing within the warranty period."

Plain language. Specific duration. Clear inclusions and exclusions. A defined process for claims.

---

Using your warranty as a sales tool

A clearly defined warranty is a trust signal, not just a protection mechanism. Customers making a large purchasing decision want to know you'll be there if something goes wrong.

Highlighting your warranty in the estimate — briefly, without making it the centrepiece — differentiates you from contractors who say nothing about it:

"All workmanship is covered by our 1-year warranty. See terms below for details."

One line in the estimate header. It doesn't require explanation. Customers read it, note it, and it increases confidence without requiring a conversation.

The contractors who hide their warranty language in fine print miss this opportunity. The contractors who have no warranty terms miss both the trust signal and the protection. Define it clearly, state it prominently, and let it do both jobs.