Ely Roofers installs and repairs flat roofs for homeowners in Histon, and this page gives you an honest picture of typical costs and the factors that push them up or bring them down.
A flat roof job in Histon can cost anywhere from under £200 for a small localised repair to well over £4,000 for a large re-cover with deck replacement and upgraded insulation. That range is not about different roofers quoting wildly different margins - it reflects genuinely different scopes of work. The best way to understand a quote is to understand what drives the price in the first place.
The timber deck is the base the membrane sits on. When it is sound, a re-cover is relatively straightforward. When it has absorbed moisture - from a slow leak, from condensation, or from poor ventilation in the roof build-up - sections of plywood or OSB board need to come out and be replaced before the new covering goes down.
Deck replacement is charged separately from the re-cover itself, typically in the range of £35 to £60 per square metre of affected boarding, including materials and disposal. A small area of replacement on a 20-square-metre roof might add £200-£300. Widespread deck damage can add £600 or more to the base price. The honest position is that no roofer can tell you exactly how much deck replacement will be needed before the old covering is stripped - anyone who quotes a single fixed price for the whole job without seeing the deck uncovered is either guessing or hoping for the best.
Price per square metre tends to fall slightly on larger roofs because the fixed costs - getting materials and labour to site, forming the perimeter upstands - are spread across more area. On a small roof of 10-12 square metres, the cost per square metre is often noticeably higher than on a 30-square-metre roof. For a domestic extension or garage, useful reference points are:
These are honest typical UK figures and include installation labour but not deck replacement beyond minor patching.
EPDM rubber costs more to buy and fit than standard torch-on felt. The material itself is more expensive per square metre, and the installation process - cleaning and priming the deck, applying contact adhesive, carefully bonding the sheet and forming all the details - takes more time than rolling and torching felt. The trade-off is that a well-installed EPDM roof is less likely to split at seams over time and generally has a longer working life, which makes it cheaper per year of service even if the upfront cost is higher.
Torch-on felt is a legitimate and cost-effective choice, particularly where budget is the primary concern or the roof is on an outbuilding that does not need to last another 20 years. Good-quality cap sheet felt with a mineral surface, properly torched and with carefully lapped joints, can give reliable service for 12-15 years on a well-prepared deck.
Current building regulations require a minimum standard of insulation for any flat roofing work that constitutes a material change. Adding a layer of rigid insulation board above the deck - converting a cold roof build-up to a warm roof construction - is the most effective way to meet this and to reduce heat loss through the roof. It adds to the upfront cost, typically £15-£30 per square metre of insulation board plus laying costs, but doing it during a re-cover is far more cost-effective than returning to the roof later.
Whether insulation work is needed, and how much, depends on whether the project falls within the scope of building regulations and what the existing construction looks like. Ask the roofer to be clear about this before work starts.
Most domestic flat roofs on extensions and garages can be accessed from a scaffold tower or extending ladder, which is included in the quoted price as standard. Where access is genuinely difficult - a flat roof above a conservatory surrounded on three sides by structures, or a roof that can only be reached through the property - additional time and potentially additional equipment is needed, which adds cost.
For roofs above first-floor height, scaffold may be required for safe working. This is not optional if the height demands it - working at height without appropriate fall protection is not acceptable practice. Scaffold hire typically adds £300 to £600 to the cost of a domestic flat roof job, depending on what is needed and for how long.
If the existing drainage outlet is blocked or positioned at a high point of the deck, simply re-covering the roof without addressing this creates a new roof with the same old water problem. Repositioning an outlet, adding a second outlet, or installing tapered insulation to restore falls all add to the cost of the job but are necessary if the roof is to perform correctly. A roofer who does not mention drainage when they look at your roof is missing a critical part of the assessment.
A simple rectangular flat roof with one outlet and one abutting wall is the quickest and cheapest to re-cover. Every additional feature adds time and materials: a soil pipe or vent pipe coming up through the deck, a skylight or rooflight, a parapet wall all the way round, multiple abutments with walls or chimney stacks. Flashings in lead - which is the standard for most domestic applications - are cut and fitted by hand and take time to do properly. Each additional penetration or abutting wall adds to the overall price.
A localised repair - resealing an upstand that has lifted, bonding down a blister, or applying a compatible patch over a small split - is the right approach when the rest of the roof is in good condition. Repair costs for a straightforward job typically start from around £150 and rarely exceed £500 for a single-location fix. However, repairing one section of a roof that is broadly at the end of its life is not a long-term solution. If the membrane is cracking across multiple areas, if the surface is losing its granules, or if the deck has soft spots in more than one place, a full re-cover is more economical over a five-year horizon.
The only way to get an accurate price is to have the roof properly inspected before any quote is given. Any figure given over the phone without a site visit is a rough guide at best. A survey lets us assess the deck condition, drainage, access, and the amount of detailing required, so the figure we give you reflects the actual job.
If you have a flat roof on an extension, garage or outbuilding in Histon that needs attention, call us to arrange a proper inspection and we will give you a clear breakdown of what the work involves and what it will cost.
We are based in Ely and cover Histon and the surrounding area, including Cambridge and its nearby villages, Stretham, Haddenham, Witchford, Soham, and communities across the Fens. Get in touch to check whether we cover your location and to arrange a roof survey.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
