Ely Roofers carries out commercial roofing work in Girton, and this page explains what a commercial roofing project is likely to cost, and what makes the price go up or down.
Commercial roofing costs vary enormously depending on the building type, the material, the condition of the existing roof and a range of site-specific factors. A single number means very little without context, but understanding the variables helps you evaluate quotes and plan your budget realistically.
As a broad guide, commercial flat roof refurbishment using a single-ply membrane typically costs between £50 and £120 per square metre, depending on specification and site conditions. Metal sheet re-roofing on an agricultural or industrial building generally falls in the range of £30 to £80 per square metre for the sheeting itself, with the full project cost depending heavily on access, strip-out and the condition of the underlying structure.
These figures are starting points for planning purposes. A proper price for your specific building in Girton requires a site survey to establish what is actually there and what the job involves.
The most obvious driver of cost is the area of the roof. Larger roofs cost more in total, but they often have a lower cost per square metre because the fixed costs of access, mobilisation and set-up are spread over a bigger area. A 500 square metre warehouse roof is not five times the cost of a 100 square metre flat roof office - the per-metre rate usually falls as the area increases.
The substrate - the deck, the insulation and the structure below - has a significant effect on cost. If the existing insulation is wet, it must be stripped and replaced rather than covered over. Wet insulation on a large flat roof can add thousands of pounds to a project because the material must be taken down, disposed of and replaced before the new membrane can go on.
On metal-sheet buildings, corroded purlins or rails discovered during a strip-out add cost because they need repair or replacement before new sheets can be fixed to them. This is rarely visible during a ground-level inspection, which is why a survey that includes getting on the roof is important for accurate pricing.
Access is one of the most variable cost factors in commercial roofing. A single-storey unit where scaffolding can be erected on a clear concrete apron is straightforward. A multi-storey building in a constrained site, with restricted vehicle access, adds significant cost for scaffold design, crane hire or extended MEWP time.
Buildings where the surrounding ground is soft, uneven or occupied by services (drains, underground tanks, cabling) can also add cost because the access equipment needs special base plates, outrigger pads or a different configuration to work safely.
A simple, rectangular flat roof or a plain pitched shed is at the cheap end of the scale for its material type. The price per square metre rises with complexity - multiple penetrations (rooflights, vents, extraction units), internal gutters, complex parapet details, changes of level, hips and valleys on a metal-sheet roof, and junctions with existing or adjacent structures all add time and materials.
Each penetration or detail requires cutting, shaping and bonding or sealing to a standard that prevents water entry. On a complex industrial or office building, the detailing work can account for a substantial proportion of the total labour cost.
Within each material type there is a wide range of specifications. A 1.2mm EPDM membrane is cheaper than a 1.5mm membrane of the same product range. A standard polyester-coated steel sheet is cheaper than an aluminium sheet or a PVdF-coated steel. A basic three-layer torch-on felt system is cheaper than a high-performance system with an uplift-rated mechanical fixing pattern designed to meet structural engineer requirements.
The cheapest specification is not always the most cost-effective over the life of the building. A system that lasts 15 years versus one that lasts 30 years will have very different whole-life costs when you factor in re-roofing, disruption and lost productivity at re-roofing time.
If the existing roof needs to be fully stripped, the cost of taking the material off the building, loading it and disposing of it at a licensed waste site needs to be included. On a large commercial roof, this can be a significant sum. Roofing waste cannot go to a skip without proper documentation in many cases, and the cost of disposal has increased considerably in recent years.
A re-cover (laying the new system over the existing surface) avoids strip-out costs but is only appropriate when the deck is dry, sound and structurally capable of carrying the additional weight. Your roofer should be able to explain clearly why they are recommending strip-out or re-cover based on survey findings.
Not everything pushes the price up. There are situations where a job can be done more economically than you might expect.
A quote for a commercial roofing project should itemise the main components so you can see what you are paying for. Be cautious about a single lump-sum figure with no breakdown. At a minimum, a quote should show:
If a quote does not show this detail, ask for it in writing before you proceed. It is the only way to compare two quotes for the same scope of work accurately.
For commercial buildings, the installation price is only part of the cost picture. The maintenance requirements of the system, its expected service life and the ease and cost of repairs all affect the total expenditure over the building's life.
A cheap installation that needs replacing in 12 years will cost more over 30 years than a properly specified system installed at higher cost that lasts the full period. For owner-occupiers in Girton planning to remain in a building long-term, whole-life cost is a more useful figure than day-one price. For landlords and investors, it also affects the maintenance liability and, in some cases, the rateable value and insurability of the building.
The only way to get a realistic cost for your commercial roof is a proper site survey followed by an itemised quote. When you ask for a survey, check that it includes getting on the roof, since many problems are not visible from the ground. Call us to arrange a visit and we will give you an honest assessment of what the work involves and what it is likely to cost.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
