Commercial Roof Replacement Cost per m2

National cost guides mostly deal with house roofs, so treat these figures as a yardstick for the material and fitting, not as a price for a warehouse. The ranges below come from Checkatrade's cost guides, with the date of the table in each case. They are typical UK ranges, not Crown prices.

The gap between the GRP figures shows how much insulation alters a price. Large commercial roofs and insulated metal panels sit outside those tables, so for them the survey and the written quote set the number. A per-metre rate also assumes a plain roof. Penetrations, upstands, outlets and access all fall outside the rate, which is why a rate and a final total rarely agree.

Size changes the price per metre in both directions. A large roof spreads the cost of site set-up, but it also needs more material handling, more edge protection and often more days on site. A small shop roof with awkward access can cost more per metre than a big unit with an open yard.

The covering tells only half the story. What sits beneath it matters just as much: insulation thickness, vapour control layers, the deck itself and whether any section has to be replaced. Upstands, parapets, rooflights, plant bases and outlets all need detailing. Falls may need correcting with tapered insulation, which adds cost but removes ponding.

Access sets another part of the bill. A building near a pavement or road may need scaffold licensed by the highway authority, a crane or hoist for rolls of membrane and insulation, and fencing to keep the public clear. A crane cannot work within 6 km of Gatwick without the airport's permit, though kit under 10 m, or surrounded by taller trees or structures, is exempt, so we raise it at survey. If the old covering contains asbestos, which is a real possibility on buildings from before 2000, removal is a separate matter altogether, and HSE rules apply.

The lowest price per metre is not always the best value across a roof's working life. A repair fixes a specific fault and suits a roof with plenty of life left. An overlay, where a new covering goes over the old, avoids stripping costs but adds weight and only works if the insulation below is dry. Full replacement costs the most at the start and resets the clock, with the chance to correct falls and add insulation.

Lifespans give a rough guide, though they are typical ranges, not promises. Less gives felt as 10 to 20 years and glass-reinforced plastic as 25 to 40, while GreenSpec gives EPDM as 20 to 30. Setting a price against a typical life can show that a dearer system works out no dearer in use.

If you are weighing a liquid coating against a new covering, our answer on commercial roof coating vs replacement explains when each makes sense. To see how your own roof is assessed, our guide to commercial roof condition surveys shows what a survey records.

Start with a survey. We look at the roof, take photos of the deck, seams, outlets and details, and test for wet insulation where the roof looks suspect. After that we give you one written total price, not a per-metre guess.

When you have more than one quote, ask each contractor the same questions. Which system is proposed, and why? What is the insulation specification? What happens if rotten deck is found? Who arranges any highway licence and scaffold? Is VAT inside the figure? The answers matter more than the headline number. Checkatrade states that its repair table figures exclude VAT, so confirm the position on every quote you compare. Our guide to VAT on commercial roof work goes through the basics.

Do not choose on price alone. A quote that is far below the others usually leaves something out, such as insulation, falls or edge protection. Ask for the scope in plain words, and ask what the written guarantee period covers. You can read about the full range of work on our commercial roofing page.