Ferndown at a glance
- Postcode districts
- BH22
- Population
- about 17,650 (GeoNames)
- Council area
- Dorset Council
- Building approval
- Dorset Council building control, or a registered building control approver
- Nearest main town
- Bournemouth, about 6 miles
- Guide price region
- South West (+3% on West Midlands rates)
Why upgrade to a warm roof in Ferndown?
Small commercial buildings in Ferndown with large flat roofs can lose a lot of heat through them. Where the roof is being replaced, upgrading the insulation at the same time is required in most cases and helps reduce running costs for the occupier.
Ferndown's flat roofs are mostly on bungalows with flat-roofed side extensions and dormers, with plenty on lock-up garage blocks on estates too. The South West averages roughly 1,260 mm of rain a year and many roofs face wind off the Atlantic, so we specify fixings and edge details for wind uplift as well as drainage.
How much does a warm roof upgrade cost in Ferndown?
For Ferndown we use South West rates: £2,900–£5,050 is the guide for a 20 m² extension roof in EPDM with a new deck and insulation, VAT included. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM, new deck + insulation | £2,900–£5,050 |
| Extension (20 m²), EPDM with sedum green roof | £4,550–£8,350 |
How long does a warm roof last?
The insulation in a warm roof should last for the life of the waterproofing above it, as long as it stays dry. Rigid PIR boards don't settle or slump in the way some loose insulation can.
The waterproofing is what sets the timescale. EPDM is typically quoted at 25 to 50 years, GRP at 20 to 40 years and modern torch-on felt at 15 to 25 years with good specification and care. A warm build-up also helps the deck, because keeping it warm and dry lowers the risk of condensation rot. If the waterproofing fails and water gets into the insulation, the wet boards should be replaced, so leaks need prompt attention. The lifespan guide compares the systems.
What's included?
- Vapour control layer on the warm side of the insulation
- Building control or building standards handled where needed
- Survey of the deck, joists and existing insulation
- Rigid insulation boards sized to the U-value target
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?
- Wimborne Minster · 4 mi
- Bournemouth · 6 mi
- Christchurch · 7 mi
- Poole · 7 mi
- New Milton · 11 mi
- Salisbury · 19 mi
Warm roof insulation upgrades in Ferndown: questions
Do you cover Ferndown?
Yes. Ferndown is part of our Dorset coverage, including postcode districts BH22. 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 Ferndown?
Where the work needs approval it goes to Dorset 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 warm roof upgrade cost in Ferndown?
£2,900–£5,050 for a 20 m² extension roof in EPDM with a new deck and insulation, at South West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Is a warm roof worth it on a garage?
On a detached, unheated garage, usually not, as there is no heated space to protect and the thermal rules don't normally apply. On an integral or heated garage, or one being converted into a room, it is.
Can you insulate a flat roof from inside instead?
It is possible, but insulating between or under the joists creates a cold roof, which needs ventilation and carries a higher condensation risk. When the roof is being re-covered anyway, a warm roof from above is usually the better option.