Roof Guarantees, Warranties and Insurance-Backed Guarantees Explained

Three roofers have quoted for your re-roof and all three mention a guarantee. One says ten years, one says twenty five years, one says "fully insurance backed". None has handed you a document. Six months later the ridge starts letting water in and you find out what those words were worth.

Roof guarantees are three separate things wearing the same word, protecting you against three different problems. Getting them straight before you sign is worth more than almost anything else you can do at quoting stage.

At a Glance: The Three Layers of Protection

The gap most homeowners fall into is between rows two and three. An IBG does not insure you against your roofer being bad. It insures you against your roofer no longer existing.

What an Insurance-Backed Guarantee Actually Covers

The NFRC Competent Person Scheme, in guidance published 9 July 2024, describes an IBG as automatically issued for roof refurbishment work up to £50,000 put through the scheme, protecting the property owner for ten years after completion and payment, and underwriting "the installing contractor's written guarantee for faulty workmanship or materials if the contractor ceases trading".

That last clause is the whole product. Read the trigger conditions and it gets narrower still. QANW, quoted on the CORC scheme's FAQ page, states that "an insurance backed guarantee only covers if the installer has dissolved". CORC's own customer page lists the trigger as "liquidation, receivership, administration or winding up due to bankruptcy, state retirement or the death of the principals". NFRC and HomePro use the looser phrase "ceases trading".

Those are materially different bars, and none of them is met by the most common real world problem: a roofer who is still trading perfectly happily and simply will not return your calls. For that situation an IBG does nothing at all, and your remedy is the statutory one against the trader.

The exclusions nobody reads out

CORC's customer page sets out limits that rarely make it onto a quote. IBGs cover new work and materials only, not repairs. They do not cover paints or resins. They cover roof work only. And the one that catches people: "you MUST have the members company guarantee to run alongside your guarantee otherwise, it will be void."

That is worth sitting with. The IBG underwrites the contractor's own written guarantee. If you never received the contractor's guarantee document, or you have lost it, there is nothing for the policy to underwrite. File both, in the same place, the week the work finishes.

The "25% rule" does not exist

A claim circulates widely that the NFRC recommends an IBG for any job affecting more than 25% of a domestic roof. There is no NFRC page that says this. What NFRC actually says on its contractor guidance is that it recommends purchasing an IBG which backs up but is independent of the contractor's own guarantee, with no percentage threshold attached anywhere.

The nearest genuine 25% figure belongs to a completely different regime. Approved Document L's thermal element rules bite when more than 25% of the external building envelope is renovated, or, per Bauder's technical guidance on the June 2022 England changes, when more than 50% of an individual roof surface is renovated. That is an insulation requirement under the Building Regulations. It has nothing to do with guarantees, and the two have been welded together across a lot of roofing content.

What an IBG costs, and why the price is the story

Installsure publishes a trade price list for IBG premiums, including 12% Insurance Premium Tax. Note the page carries no publication date, so treat the figures as indicative.

HomePro, in guidance last updated 3 August 2026, gives a comparable figure from a different angle: for a typical re-roof of around £8,000 the premium averages around £48 including IPT, as a one off per installation rather than an annual charge. The two sources price the same job differently, so the honest range is roughly £17 to £92 depending on contract value and how long the firm has traded.

Either way, a decade of insurance-backed cover on a mid sized re-roof costs the roofer roughly the price of a tank of fuel. A roofer telling you an IBG is not worth it on a job this size is telling you something about the business, not about the insurance. And note the new business column: firms trading under two years pay three to five times more, which is itself informative.

There is a catch in how you check. HomePro's own guidance to installers is that they cannot itemise the IBG separately on a quote, because selling or advising on insurance requires FCA authorisation that installers do not hold, so the instruction is to build it into the price and show it as included. You therefore cannot verify it from the quote. Ask for the policy document and the policy number instead.

The Guarantee You Cannot Read Before You Sign

Your rights against the roofer come from the Consumer Rights Act 2015. Section 49 treats every contract to supply a service as including a term that the trader must perform it with reasonable care and skill. Section 55 gives you the right to require repeat performance, and says the trader "must bear any necessary costs incurred in doing so (including in particular the cost of any labour or materials)". Those rights run against the trader you paid, not the manufacturer.

How long they last is where the headline numbers get slippery. Under section 5 of the Limitation Act 1980 an action founded on simple contract cannot be brought after six years from when the cause of action accrued. Section 8(1) gives twelve years for an action on a specialty, meaning a guarantee executed as a deed. In Scotland, section 6 of the Prescription and Limitation (Scotland) Act 1973 extinguishes the obligation after five years.

So a "ten year guarantee" given as an ordinary signed document has a limitation cliff at year six in England and Wales, and at year five in Scotland. The same promise executed as a deed runs to twelve. It costs nothing to ask which one you are being given.

Manufacturer warranties: mostly unreadable

Here is what the major manufacturers' public pages turn up. IKO UK publishes the structure of two named guarantees: a Single Point Guarantee placing responsibility for materials, approved contractor workmanship and IKO's design input with the manufacturer, and a Linked Guarantee carrying two signatures. Conditions include registered or approved contractors only, on site inspections by IKO technical engineers, and maintenance in line with BS 6229. Durations and full terms are not stated. Bauder says its guarantees can cover the products it sells, design features it was involved in, and installation by an approved installer, with the duration reflecting "the system, its life expectancy and building requirements". No figure is given and no terms document is published. The frequently quoted "20 year ClassicBond EPDM guarantee" comes from Rubber4Roofs, a distributor rather than the manufacturer, and is conditional on the installer having attended that distributor's training course.

For Marley, Sika, Redland, Klober, Elevate, Alumasc and Danosa, no public terms document could be found at all. That absence is the point. You are being asked to place value on a twenty five year manufacturer's guarantee whose terms you cannot obtain before signing. Ask for the guarantee document at quoting stage, not after the scaffold comes down.

One more trap: substitution. IKO states that using components not approved as part of a single ply flat roof system can invalidate the manufacturer guarantee, and that IKO Polymeric will not issue guarantees where other manufacturers' products are mixed in without prior approval from its technical department. A roofer swapping one insulation board for a cheaper equivalent can void a long warranty quietly, and neither of you will find out until you claim.

Worth knowing about the badges, too. TrustMark states that registered businesses are expected to provide a minimum of two years financial protection for completed works, covering prepayments, workmanship, rectification of defects or non-compliance with Building Regulations, and public liability. Two years, not ten. Homeowners routinely read the logo as a decade of cover.

Regional Price Differences

Regional variation affects the job, not the guarantee, and that produces a quirk worth understanding.

MyJobQuote's regional table, updated 26 August 2026, puts a standard semi-detached gabled roof replacement at £4,000 to £4,900 in London (25% to 30% above the national average), £3,750 to £4,500 in the South East, £3,250 to £3,750 across the South West and both Midlands regions, and £2,750 to £3,400 in the North East and Northern Ireland. MyBuilder's rates, updated 21 August 2026, show the same shape hourly: £40 to £60 in London against £20 to £35 in the North.

IBG premiums, though, are banded on contract value alone. A London homeowner and a North East homeowner both sitting in the same band pay the same premium for the same ten years of cover, so the regional premium buys nothing extra in protection. It can, however, push a job across a band boundary. A re-roof at £14,500 sits in the £27.52 band; the same specification quoted at £15,500 lands in the £48.16 band. The steps are small in absolute terms, which is precisely why "it costs too much" is not a credible reason to skip one.

Comparing roofing quotes? Find local roofers at localroofer.directory and ask each one for three documents before you decide: their own written guarantee, the manufacturer's guarantee terms for the system they are proposing, and the IBG policy number. A firm that can produce all three in a week is telling you a lot.

Frequently Asked Questions

Does an insurance-backed guarantee cover bad workmanship?

Only indirectly. It underwrites the roofer's own written guarantee for workmanship or materials once the roofer ceases to exist, with providers defining that as dissolution, liquidation, receivership, administration, bankruptcy, retirement or death of the principals. While the firm is still trading, your claim is against the firm under the Consumer Rights Act 2015, not against the policy. And if you do not hold the roofer's own guarantee document, CORC states the IBG is void.

How much should an insurance-backed guarantee add to my bill?

Published trade premiums run from £17.20 on a job under £5,000 to £86.72 at £25,000 to £30,000 for an established NFRC business, per Installsure's undated price list. HomePro put a typical £8,000 re-roof at around £48 including Insurance Premium Tax in August 2026. Installers cannot itemise it on your quote for FCA reasons, so ask for the policy document and number rather than looking for a line item.

Is a 10 year guarantee actually enforceable for 10 years?

Not always. In England and Wales a claim on a simple contract must be brought within six years under section 5 of the Limitation Act 1980, while a guarantee executed as a deed gets twelve years under section 8(1). Scotland extinguishes the obligation at five years under the 1973 Act. A ten year promise in an ordinary document runs out of legal road at six, which is why it is worth asking whether the guarantee is given as a deed.

What if I paid by credit card?

Section 75 of the Consumer Credit Act 1974 makes the card issuer jointly and severally liable with the supplier for breach of contract or misrepresentation. The £100 to £30,000 test applies to the cash price attached by the supplier, not the amount you put on the card, so paying only the deposit by credit card can protect the whole contract value. That protection survives the roofer's insolvency without any policy document, dissolution test or trade body involvement.