Barnet at a glance
- Postcode districts
- N20, N11, N14, N12, EN4, N3, EN5, NW7 and 1 more
- Council area
- London Borough of Barnet
- Building approval
- London Borough of Barnet building control, or a registered building control approver
- Guide price region
- London (+20% on West Midlands rates)
Why choose a liquid-applied roof in Barnet?
If a flat roof in Barnet is ageing but still dry, firmly bonded and on a sound deck, a reinforced liquid system can be applied over it. That avoids the cost and mess of a full strip-out, provided the moisture and adhesion checks at survey show the existing roof is fit to build on.
In a town like Barnet, flat roofs are commonly found on mansard and dormer loft conversions or Victorian and Edwardian terraces with flat-roofed back additions. The Thames basin is one of the drier parts of Britain at roughly 730 mm of rain a year, but summer heat is the bigger test here: dark membranes on south-facing roofs swing a long way in temperature.
How much does a liquid-applied roof cost in Barnet?
Guide price in Barnet: £2,450–£3,900 for a typical 18 m² garage roof in a liquid-applied system, including VAT at London rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Single garage (18 m²), liquid-applied | £2,450–£3,900 |
| Balcony (12 m²), liquid-applied, scaffold | £2,300–£3,900 |
| Single garage (18 m²), EPDM rubber | £1,900–£3,350 |
| Extension (20 m²), EPDM, new deck + insulation | £3,350–£5,850 |
Do building regulations apply if a liquid coating goes over my roof?
They can. In England, Wales and Northern Ireland, re-covering more than half of a roof over a heated room is usually renovation of a thermal element, even when the new membrane goes over the old, so the roof should be insulated towards the renovation standard where feasible; for a Scottish property, the local building standards team will confirm whether a warrant is required.
A minor coating repair to a small area is different from re-covering the whole roof. Where insulation is needed, an overlay is not always practical, because the insulation has to go under a new waterproof layer. In that case we may recommend stripping to the deck, fitting a warm roof and applying the liquid system on top. Where approval applies, we deal with the paperwork; details are on the building regulations page.
What's included?
- Primer matched to the substrate
- Fleece-reinforced liquid membrane applied to the specified thickness
- Detailing of upstands, outlets, pipes and corners before the main area
- Survey of the existing roof, including moisture and adhesion checks
Building regulations in England
Replacing more than half of a flat roof over a heated room usually counts as renovating a thermal element, so the roof is insulated to around 0.16 W/m²K where that's technically and economically feasible, and the work is notified to building control: the council or a registered building control approver, unless a registered competent person self-certifies it. A roof on a new extension is built to 0.15 W/m²K. Patch repairs, and most unheated detached garages, don't trigger the upgrade. Structural changes, or a new covering that adds 15% or more to the roof's weight, also need approval. More on the rules.
Which nearby areas do we also cover?
Liquid-applied roofing in Barnet: questions
Do you cover Barnet?
Yes. Barnet is part of our London coverage, including postcode districts N20, N11, N14, N12, EN4, N3 and 3 more. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in Barnet?
Where the work needs approval it goes to London Borough of Barnet building control, or a registered building control approver. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does a liquid-applied roof cost in Barnet?
£2,450–£3,900 for a typical 18 m² garage roof in a liquid-applied system, at London guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
What is a fleece-reinforced liquid roof?
It is a liquid membrane with a polyester fleece embedded between coats. The fleece adds strength, helps control thickness and resists cracking where the surface moves slightly.
Does a liquid roof smell when it is applied?
Some systems, particularly PMMA, have a strong odour during application, while many polyurethane and water-based products are milder. We tell you what to expect and plan around windows and vents.