Guarantee and Warranty Obligations: What You Actually Owe

SiteKiln gives you plain-English information, not legal advice. If a customer is threatening legal action over defective work, talk to your insurer or a solicitor before replying.

‍‌‌​​‌​​‌​‌‌​​‌​‌‌​‌​​​​​​​‌‌‌‍# Guarantee and Warranty Obligations, What You Actually Owe

You don't owe customers a magic "lifetime guarantee", but you do carry legal obligations that last years, whether you write anything down or not. The trick is knowing where your real liability ends and normal wear and tear begins.

1. Contractual guarantee vs your legal duties

Two layers are always in play on every domestic job:

Contractual guarantee · what you've actually promised in your quote, terms and conditions, or warranty card. For example: "12-month workmanship guarantee on all plumbing."

Statutory rights · what the law gives your customer whether you mention it or not.

For domestic work, you're a "trader" and your customer is a "consumer", so the Consumer Rights Act 2015 (CRA) applies.

The key section

Section 49 CRA 2015: "Every contract to supply a service is to be treated as including a term that the trader must perform the service with reasonable care and skill."

That's automatic. You can't write it out of your contract, disclaim it in your T&Cs, or pretend it doesn't exist.

"Reasonable care and skill" means:

• Doing the job to the normal professional standard for your trade
• Following industry standards, codes of practice, building regulations, and manufacturer installation instructions
• Using appropriate materials for the application
• Not cutting corners that a competent tradesperson wouldn't cut

You can add a guarantee on top (e.g., "5-year guarantee on the boiler install"), but you cannot remove the baseline statutory rights. Your guarantee is extra, the CRA is the floor.

2. Limitation periods: how long can they chase you?

This is about how long a customer has to start a court claim · not how long you "guarantee" the work.

Under the Limitation Act 1980:

In practice:

• Most domestic construction jobs are simple contracts · the customer has up to 6 years to bring a claim about your workmanship
• The clock usually starts when the work was done badly (the breach), not when they first notice the problem · though in practice these are often close together
• For latent defects (problems from view), the clock can start later under negligence · from when the damage could reasonably have been discovered

What this means for your "1-year guarantee":

A 1-year workmanship guarantee expiring doesn't make you untouchable. It means your extra promise has ended. Your CRA duties and the 6-year limitation period still run in the background.

A customer who discovers a genuine defect in your workmanship at year 3 is still within their legal rights to pursue you, guarantee or no guarantee.

3. What's a "defect" vs what's just a building doing its thing

You're not on the hook for every hairline crack or squeak forever. The law and industry practice broadly split things like this:

Defect, your responsibility (if within limitation and linked to your work)

• Poor workmanship · out of level, badly fixed, wrong products, not to specification
• Defective materials that were obviously unsuitable or not as specified (though if the customer chose and supplied the materials, that shifts responsibility)
• Not following building regs, manufacturer installation instructions, or relevant British Standards
• Serious failures · leaks, structural movement from under-spec foundations, dangerous electrics, tiles lifting from inadequate preparation, flat roof failure from poor detailing

Normal wear, settlement, and movement, generally NOT your responsibility

• Shrinkage cracks in plaster, render, and around door frames as a new build or extension dries out · fine hairline cracks in the first 12-18 months are expected and normal
• Timber movement · doors sticking or gaps appearing seasonally as timber absorbs and releases moisture. This is how wood works, not a defect
• Minor gaps opening at skirtings, architraves, and worktop joints · seasonal thermal and moisture movement
• Normal wear on floor finishes, sealant, mastic, grout, and painted surfaces where it's clearly age and use
• Fading, discolouration, or weathering of external materials exposed to UV and rain

The grey area

Customer maintenance failures. If they never cleaned the gutters and the fascia rotted, that's not your defect. If they never ventilated the bathroom and the silicone went mouldy, that's not your workmanship. If they painted over trickle vents and the windows condensed, that's their problem.

Industry practice (especially on new builds and extensions):

• Builder expected to address significant snags and defects in a defects/rectification period: typically 6-12 months after practical completion
• After that, only genuine defects in workmanship or structure · not cosmetic ageing or normal movement

When someone calls 2-3 years later, the key questions are:

1. Is this actually a defect (bad work or materials) or just the building doing what buildings do?
2. Has the customer maintained it · cleaned gutters, resealed wet areas, ventilated properly, repainted where needed?
3. Did anyone else interfere with or modify your work after you finished?

If it's normal movement or poor maintenance, it's reasonable to say it's not your responsibility.

4. What a "reasonable" guarantee looks like

There's no single legal standard for guarantee length. But here's what's typical in the trade:

A sensible approach for most trades

• Workmanship guarantee of 12 or 24 months for domestic work
• Clear wording that product guarantees are separate and sit with the manufacturer
• State that normal wear, shrinkage, seasonal movement, and lack of maintenance are not covered
• State that your guarantee does not remove the customer's statutory rights under the Consumer Rights Act 2015

That's fair, transparent, and lines up with how new-build developers, warranty providers, and trade bodies treat defects vs wear.

5. Protecting yourself: handover and snagging

A lot of "warranty" disputes are actually communication failures. You can prevent most of them by tightening up how you hand over a finished job.

Before and at completion

1. Do a snagging walk-round with the client · go through the work together, list any issues, and agree what will be put right and by when
2. Get them to sign off practical completion once snags are dealt with · even a text or email saying "I'm happy with the work, snags done" is better than nothing
3. Take completion photos · every room, every elevation, close-ups of key details. Timestamped. These are your evidence if there's a dispute later

Give them a handover pack

Even a simple one-page document helps:

• What you've done · scope of work completed
• How to look after it · ventilation advice, drying times, re-sealing schedule, re-painting intervals, cleaning instructions
• What your workmanship guarantee covers and for how long
• What it doesn't cover · normal shrinkage, seasonal movement, wear and tear, failure to maintain
• Copies of manufacturer warranties and certificates · gas safety, electrical installation certificate, FENSA, EPC, building control completion certificate

The maintenance advice is your best defence. When someone calls 3 years later saying "your work failed", you can point to the handover pack that told them to reseal the shower every 12 months, and they didn't.

Written terms and conditions

Even a simple one-pager covering:

• Your services will be performed with reasonable care and skill (mirrors CRA s.49)
• Workmanship guarantee: what's covered, for how long, how to make a claim
• Exclusions: normal wear, shrinkage, third-party interference, lack of maintenance, customer-supplied materials
• Your guarantee does not affect the customer's statutory rights

6. When a customer comes back years later

Scenario: customer calls 3 years after you finished, saying "your work's failed, I want you to fix it for free."

Step 1: Stay calm and get the facts

• Ask for photos, dates, and exactly what's wrong
• Check your records: when you did the job, what you installed, what you guaranteed, what handover advice you gave
• Don't admit liability or promise anything in that first conversation

Step 2: Work out the likely cause

• Product failure (boiler heat exchanger, broken fitting, failed seal) · check if the manufacturer warranty is still live and tell the customer how to claim on it. That's the manufacturer's problem, not yours, unless you installed it incorrectly.
• Your workmanship · ask yourself honestly: did you do it to a proper standard? Did you follow regs and manufacturer instructions? If you cut a corner, own it.
• Wear and tear / maintenance failure · if the issue is clearly caused by age, use, or the customer not maintaining the work, explain that.

Step 3: Apply common sense

• If it's just outside your guarantee and clearly your error · it's often cheaper for your reputation to fix it as a goodwill gesture. Quietly tighten your process so it doesn't happen again.
• If it's clearly wear and tear or poor maintenance · explain that politely and offer a paid repair as an option.
• If it's borderline · a reasonable compromise (you supply materials, they pay labour, or vice versa) often defuses the situation.

Step 4: If they threaten legal action

• Remember they have up to 6 years to claim on a simple contract (12 on a deed) · so don't dismiss it as "too late" unless you're sure
• Set out your position in writing: when the work was done, what you guaranteed, why you believe the issue isn't a defect in workmanship (referencing industry norms, normal movement, maintenance expectations)
• Contact your insurer before replying further if the claim looks serious · your professional indemnity (PI) or public liability (PL) policy may cover the defence costs and any settlement
• Don't admit liability in writing without talking to your insurer first · it can affect your cover

Most disputes settle with a clear, fair explanation plus a sensible paid repair quote. The ones that go to court are where communication broke down completely or the defect is serious and obvious.

What to do next

1. Review your current guarantee wording · does it clearly state what's covered, for how long, and what's excluded?
2. Create a simple handover pack · even a one-page template with maintenance advice and guarantee terms (see our Document Hub for templates)
3. Start taking completion photos on every job · timestamped, stored in your cloud backup
4. If a customer is currently chasing you: get the facts, check your records, and talk to your insurer before admitting anything in writing
5. Read our guide on snagging and defects for the defence side of customer claims

Sources

• Consumer Rights Act 2015, s.49 (reasonable care and skill), s.50 (information about the trader or service), s.54 (right to repeat performance or price reduction) · legislation.gov.uk/ukpga/2015/15
• Limitation Act 1980, s.5 (simple contract · 6 years), s.8 (deed · 12 years), s.2 (tort/negligence · 6 years) · legislation.gov.uk/ukpga/1980/58
• Supply of Goods and Services Act 1982, s.13 (implied term of reasonable care and skill · still applies to B2B) · legislation.gov.uk/ukpga/1982/29
• Building Regulations 2010 · legislation.gov.uk/uksi/2010/2214

How this site is funded →

Spotted something wrong or out of date? Email us at hello@kilnguides.co.uk.

In crisis? Samaritans 116 123 · Mental health support

How this site is funded →