Portsmouth at a glance
- Postcode districts
- PO1, PO2, PO3, PO4, PO5, PO6
- Population
- about 208,100 (GeoNames)
- Council area
- Portsmouth City Council
- Building approval
- Portsmouth City Council building control, or a registered building control approver
- Nearest main town
- Southampton, about 15 miles
- Guide price region
- South East (+10% on West Midlands rates)
Why choose a liquid-applied roof in Portsmouth?
For businesses and landlords in Portsmouth, a cold-applied liquid roof means no flame on site and, with some systems, a short cure time. That can make it easier to work around occupied buildings, tenants and opening hours than a system that needs hot works or a long strip-out.
Portsmouth's flat roofs are mostly on lock-up garage blocks on estates, with plenty on low-rise post-war blocks of flats too. Much of the South East sits in the drier Thames catchment at roughly 730 mm of rain a year, so the usual failures are at joints, upstands and outlets rather than from sheer volume of rain.
How much does a liquid-applied roof cost in Portsmouth?
Guide price in Portsmouth: £2,250–£3,600 for a typical 18 m² garage roof in a liquid-applied system, including VAT at South East 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 | £2,250–£3,600 |
| Balcony (12 m²), liquid-applied, scaffold | £2,100–£3,600 |
| Single garage (18 m²), EPDM rubber | £1,750–£3,100 |
| Extension (20 m²), EPDM, new deck + insulation | £3,100–£5,350 |
Can a liquid roof go over my existing roof, and what preparation is needed?
Yes, if the existing roof is dry, firmly bonded and sitting on a sound deck. A liquid membrane is only as good as what lies beneath it, so we test the old roof before agreeing to overlay it.
At survey we check for:
- Trapped moisture: soft spots, blisters or wet insulation mean the roof should be stripped, because water sealed in will cause new blisters and decay.
- Deck condition: any sponginess or deflection needs repair first.
- Adhesion: on felt and asphalt, loose areas are cut out and patched, and the existing surface must take the primer properly.
- Falls and ponding: a coating follows the roof as it is. If water ponds now, it will pond on the new surface too unless the falls are corrected.
Preparation then follows: loose chippings removed, the surface cleaned and left to dry, blisters cut back and repaired, cracks filled, and the right primer applied. On older felt, mineral surfaces may need extra cleaning to give a good bond. Where the tests fail, we say so plainly and quote for a strip and re-roof. Read more on ponding water.
What's included?
- Surface cleaning, repairs and removal of loose material
- Primer matched to the substrate
- Detailing of upstands, outlets, pipes and corners before the main area
- Fleece-reinforced liquid membrane applied to the specified thickness
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 Portsmouth: questions
Do you cover Portsmouth?
Yes. Portsmouth is part of our Hampshire coverage, including postcode districts PO1, PO2, PO3, PO4, PO5, PO6. 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 Portsmouth?
Where the work needs approval it goes to Portsmouth City Council 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 Portsmouth?
£2,250–£3,600 for a typical 18 m² garage roof in a liquid-applied system, at South East guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
How long does a liquid roof take to cure?
That depends on the product and the weather. Some systems are rain-resistant within an hour or so, others take longer, and full cure can take a day or more in cool weather.
Can liquid roofing be applied in the rain?
No. The surface must be dry, and most systems need a dry window while they cure. Some fast-curing products shorten that window, but the team will not apply onto a damp roof.