Flat roofing insurance: when the percentage question knocks you out
The percentage question, and why it decides your quote
Somewhere on every roofing form is the question: what percentage of your work is flat roofing? It looks innocent. It’s actually one of the main switches that decides whether the system quotes you or shows you the door.
Each online insurer sets its own maximum. Cross it — even by a little, even honestly — and you’re declined with no explanation. The cut-offs vary from insurer to insurer for no reason you’ll ever see, which is why the same answers get accepted on one site and refused on the next. It feels arbitrary because, from the outside, it is.
What the question is really trying to measure
Insurers aren’t afraid of flat roofs. They’re afraid of what has traditionally been used to build them: hot bitumen and torch-on felt, which means flame on a roof and a fire risk that dwarfs anything in pitched tiling. Flat work has also produced more leak and workmanship claims over the years — ponding water finds every mistake.
The percentage box is a crude stand-in for all of that. It can’t ask how you build a flat roof. It just assumes the worst.
EPDM, GRP and liquid systems are not torch-on
Here’s what the tick-box can’t see. A huge share of modern flat roofing involves no flame at all: EPDM rubber membranes glued down cold; GRP fibreglass laid up wet; liquid-applied waterproofing; self-adhesive and cold-applied felt systems. The fire risk profile of that work is nothing like running a gas torch across a bonded felt roof over someone’s kitchen extension.
If most of your flat work is cold-applied, you may be carrying a decline — or a torch-on price — for a risk you don’t actually present. If you do use a torch, that’s a real underwriting factor and needs declaring properly, with the right heat conditions on the policy — see our hot works and torch-on page for how that works.
Getting rated on what you actually do
The broker route replaces one percentage with a proper picture. A presentation for a flat roofing risk sets out the split of your work by system — how much EPDM, GRP, liquid, single-ply, felt; how much of the felt is torch-on versus self-adhesive or cold-applied; where you use hot air instead of flame; what you do at vulnerable details; your experience and claims record.
An underwriter reading that can price the risk in front of them instead of the worst case a form has to assume. Sometimes that means a better price. Sometimes it simply means cover exists where the portals said no. Either way you end up insured on accurate answers — which is the only kind of insurance worth paying for.
Answer the percentage question honestly, whatever it costs
One warning. When an online form declines you at your honest percentage, the temptation is to knock the number down and try again. Don’t. Your answers form the basis of the contract; if a claim arises from flat work and the insurer finds the real split, the claim can be cut down or refused and the policy voided — and a voided policy follows you onto every future proposal. If the honest answer fails the machine’s test, the answer isn’t a different number. It’s a different route. Call 0117 325 0027 and we’ll take your real figures to markets that can actually consider them.
Frequently asked questions
Why do insurance forms ask what percentage of my work is flat roofing?
It’s a rough proxy for risk. Flat roofing has historically meant hot bitumen and torch-on felt — fire risk — plus a higher rate of leak and workmanship claims than pitched tiling. Rather than ask detailed questions, online forms use one percentage figure and apply a cut-off to it.
What’s a typical flat roof percentage cut-off?
There’s no single market standard — each insurer sets its own, and some online products won’t take specialist flat roofers at all. That’s exactly why the same honest answer gets declined on one site and accepted on another. Broker-placed markets can consider higher flat percentages, including 100% flat specialists, on their merits.
Does EPDM or GRP count as flat roofing on the form?
Usually yes — the percentage question normally covers all flat work regardless of system. That’s the unfairness: a cold-applied EPDM or GRP job carries nowhere near the fire risk of torch-on, but a single percentage box can’t tell the difference. An underwriter reading a proper breakdown of your systems can.
Should I round my flat roof percentage down to pass the cut-off?
No. Your answers form the basis of the policy, and if a claim comes from flat work when you’ve understated it, the insurer can reduce or refuse the claim and potentially void the policy. Give your honest best estimate. If your honest number fails the online test, that’s a placement problem for a broker to solve — not a reason to bend the answer.
I’m a 100% flat roofing specialist. Can I get cover?
Specialist flat roofers are insured across the UK, generally through broker markets rather than comparison sites. Underwriters will want the detail: systems used, how much hot work, guarantees you offer, experience and claims record. We can’t promise terms, but being a flat specialist is a placement challenge, not a dead end.
Will cover cost more if I do a lot of flat roofing?
Often the rate reflects it, especially where torch-on is involved — fire and leak claims are real. But there’s a big difference between a fair rate for well-described flat work and an online price loaded for the worst assumption. Getting the method mix in front of the underwriter is usually what brings the price back to something sensible.
Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority (FRN 724952). This page is general information, not advice on a specific policy.