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Upgrades

Warm roof insulation upgrades in Shrewsbury

A flat roof in Shrewsbury that drips in cold weather without any rain is often suffering from condensation rather than a leak. Upgrading to a warm roof when the covering is replaced deals with the cause by keeping the deck above dew point and adding a vapour control layer.

Foil-faced PIR insulation boards laid over a vapour control layer to make a warm flat roofComputer-generated example image

Shrewsbury at a glance

Postcode districts
SY1, SY2, SY3
Population
about 76,782 (GeoNames)
Council area
Shropshire Council
Building approval
Shropshire Council building control, or a registered building control approver
Nearest main town
Telford, about 13 miles
Guide price region
West Midlands (baseline rates)

Why upgrade to a warm roof in Shrewsbury?

Converting a garage, loft space or outbuilding to a room in Shrewsbury changes what the roof needs to do. Once the space is heated, the roof is expected to perform to a higher standard, and a warm build-up is usually the simplest way to get there.

In a large town like Shrewsbury, flat roofs are commonly found on low-rise post-war blocks of flats or bungalows with flat-roofed side extensions and dormers. England averages roughly 870 mm of rain a year and the West Midlands sits close to that, so falls and outlets are the difference between a roof that drains and one that ponds.

How much does a warm roof upgrade cost in Shrewsbury?

At West Midlands guide rates, a 20 m² extension roof in EPDM with a new deck and insulation comes to £2,800–£4,900 including VAT. The fixed price comes after a free survey for new and replacement roofs.

JobGuide price inc VAT
Extension (20 m²), EPDM, new deck + insulation£2,800–£4,900
Extension (20 m²), EPDM with sedum green roof£4,400–£8,100

Do I have to insulate my flat roof when I replace it?

Usually, yes, if the roof is over a heated room and you are replacing more than half of its covering. In England, Wales and Northern Ireland, that counts as renovating a thermal element, so the roof should be upgraded to the renovation standard where that is technically, functionally and economically feasible.

The rules don't usually apply to patch repairs, or to an unheated, detached garage. The target U-value depends on where you live:

NationRoof renovation target
England0.16 W/m²K (homes), 0.18 (non-domestic)
Wales0.16 W/m²K
ScotlandSection 6 framework, with a domestic benchmark of 0.12 W/m²K pursued as far as reasonably practicable
Northern Ireland0.18 W/m²K

A new extension roof has a tighter target than a renovation: 0.15 in England and 0.13 in Wales. The economic test in England's guidance is a simple payback within 15 years. We handle building control or building standards where it is needed. The building regulations page sets out the approval routes in each nation.

What's included?

  • Vapour control layer on the warm side of the insulation
  • Upstands, trims and kerbs reset to the new roof level
  • 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?

Warm roof insulation upgrades in Shrewsbury: questions

Do you cover Shrewsbury?

Yes. Shrewsbury is part of our Shropshire coverage, including postcode districts SY1, SY2, SY3. 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 Shrewsbury?

Where the work needs approval it goes to Shropshire 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 Shrewsbury?

£2,800–£4,900 for a 20 m² extension roof in EPDM with a new deck and insulation, at West Midlands guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.

How thick does flat roof insulation need to be?

It depends on the insulation product and the U-value target. With common PIR boards, meeting a renovation target usually means well over 100 mm. Thinner, higher-performance boards are available where height is tight.

Can you add insulation over my existing roof without stripping it?

Sometimes, if the existing covering and deck are dry and sound. We will check at the survey and explain the risks, and our overlay or strip guide covers this choice.

Other flat roof work in Shrewsbury

Warm roof insulation upgrades in Shrewsbury: get a fixed price

Free survey and a written fixed quote for replacement and new roofs. No obligation.

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