North Walsham Roofers carries out commercial roofing repairs, replacements and new installations for businesses in Cromer and across North Norfolk.
Commercial roofs are not the same as domestic roofs. The spans are wider, the loading requirements are different, access is more complicated, and the consequences of a failure - water getting into stock, electrical equipment or a production area - are far more serious than a damp patch in a bedroom. Getting the specification right from the start matters.
We carry out roofing work on retail units, warehouses, agricultural buildings, workshops, office blocks and industrial units. Whether you need a like-for-like repair, a full re-roof or a new installation on a building under construction, the approach starts with an honest look at what is there and what will perform best over the long term.
The scope of a commercial roofing job depends entirely on the building type and roof construction. A flat-roofed retail unit requires completely different materials and detailing from a pitched agricultural barn. A warehouse with a metal deck roof is a different proposition again from a Victorian terrace converted to offices.
Any commercial roofing project should begin with a proper condition survey. On a flat roof, that means checking the falls, the integrity of the weatherproofing membrane, the condition of any insulation below it, all upstands, abutments, rooflights and drainage outlets. On a pitched roof it means checking the structure - rafters, purlins, ridge board - as well as the covering, the flashings, the ridge and hip details, and the guttering and downpipe connections.
Structural problems found during that survey need addressing before new roofing goes on. Covering a rotten purlin with new felt buys very little time. A good contractor will give you a clear breakdown of what is structural and what is purely a covering issue, so you can prioritise spending accordingly.
Flat roofs - or near-flat roofs with a slight fall for drainage - are common on commercial buildings. The material you choose affects upfront cost, ongoing maintenance, how well the roof handles standing water, and how long you can expect it to last before it needs replacing. There is no perfect material. Here is a plain account of what is available and where each one is better or worse.
Torch-on felt - sometimes called built-up felt or modified bitumen - is the most widely used flat roof covering in commercial applications across the UK. It involves two or three layers of bitumen-based sheet, heat-welded together and to upstands, forming a continuous waterproof membrane.
Pros: Lower installed cost than most alternatives, typically in the range of £40-£80 per square metre fully installed depending on specification and roof complexity. It is well understood by roofers, repairs are straightforward, and replacement sections bond reliably to existing felt in good condition.
Cons: Lifespan is typically 15-25 years depending on the quality of the system used and how well it is maintained. Felt is vulnerable to pooling water if falls are inadequate, and UV degradation accelerates on south-facing or exposed sections. Torch-on application involves open flame near insulation and timber, so fire precautions during installation are essential. Quality varies considerably between manufacturers, so the specification on the quote matters - not just the headline price.
For a straightforward re-roof of an industrial unit or agricultural building where cost is the primary concern and the roof is accessible for future maintenance, a quality built-up felt system is a sensible choice.
EPDM (ethylene propylene diene monomer) is a synthetic rubber membrane installed in large single sheets with adhesive or mechanical fixing, then bonded at laps and details. It has become increasingly popular on commercial roofs over the last 15-20 years.
Pros: Manufacturer-rated lifespans of 40-50 years are widely quoted for EPDM membranes, and real-world performance on early UK installations supports that. The material handles temperature extremes and UV exposure well. Because it comes in large sheet widths, the number of seams is low, which reduces the risk of water ingress at joints. Repairs to punctures or split seams can be carried out with compatible tape or liquid-applied EPDM, making them quick and clean. Installed cost is typically £60-£100 per square metre depending on roof size and detail complexity.
Cons: The initial cost is higher than felt. Workmanship matters enormously - a poorly formed upstand detail or a badly bonded seam will fail in the same way any membrane fails. Not every roofer is familiar with correct EPDM installation practice, so it is worth asking specifically about their experience with the system. The black surface can absorb heat in summer, which has implications for any thermally sensitive spaces below.
For a commercial building where the roof is not going to be walked on regularly and where long service life is the priority, EPDM is one of the strongest options available. The higher upfront cost is usually recovered by avoiding replacement within a 20-year period.
Liquid applied systems - typically polyurethane or acrylic-based - are brushed, rolled or sprayed onto the existing surface to form a seamless membrane in situ. They are particularly useful for roofs with many penetrations, complex geometry or rooflights where cutting sheet membrane neatly is difficult.
Pros: Seamless application means no laps to open or seams to split. They can be applied directly over sound existing felt without stripping, which reduces waste and cost. Installed cost varies widely - roughly £50-£90 per square metre - but the saving on strip-out can make this competitive on the right roof. Some systems carry manufacturer durability ratings of 20-25 years.
Cons: Surface preparation is critical. Any contamination, damp substrate or delaminating existing felt will prevent proper adhesion and shorten the life of the new membrane dramatically. Liquid systems applied in cold or damp conditions can cure poorly. They are not suitable for all existing substrates. The condition of the existing roof must be thoroughly assessed before specifying a liquid system, and any areas of wet or damaged insulation must be stripped and replaced first, which can erode the cost advantage over a full strip.
Single-ply systems such as TPO (thermoplastic polyolefin) and PVC (polyvinyl chloride) are mechanically fixed or fully adhered and hot-air welded at seams. They are common on large commercial and industrial roofs.
Pros: Light, fast to install on large areas, and hot-air welded seams are very strong when done correctly. Available in light colours including white and grey which reduce heat gain compared to dark membranes. Manufacturer lifespans of 20-30 years. Installed cost typically £70-£120 per square metre.
Cons: Hot-air welding requires specialist equipment and trained operatives - it is not a system a general roofer should attempt. PVC membranes can become brittle over time and are less tolerant of ponding water than EPDM. On smaller roofs the cost per metre tends to be higher than felt or EPDM because the equipment and skill overhead is the same regardless of size.
Single-ply systems make most sense on large flat-roofed commercial buildings - big retail units, warehouses or school buildings - where the speed of installation and the light weight have real advantages.
Many commercial and agricultural buildings have pitched roofs covered in fibre cement sheeting, profiled metal sheeting, clay or concrete tiles, or natural slate. The right material depends on the structural loading, the pitch, the intended use of the building and the budget.
Corrugated or standing-seam steel and aluminium sheeting is the most common covering on agricultural and industrial buildings. It is fast to install, relatively light, and available in a wide range of profiles and coatings.
Pros: Factory-applied coatings typically carry manufacturer durability claims of 25-40 years. Spans can be very wide without intermediate support. Cost per square metre for agricultural-grade steel sheeting can be lower than tiling on a large roof - typically £30-£70 per square metre installed depending on profile and specification.
Cons: Corrosion at cut edges and fixings is the most common long-term problem. Fixings must be compatible with the sheet material - using the wrong fixings causes galvanic corrosion that fails in a few years. Noise from rain on an unlined metal roof can be significant. Thermal bridging is a consideration if the building is heated. Any penetrations - for vents, rooflights or services - must be detailed carefully, as they are a common source of leaks.
Asbestos cement sheeting on older commercial and agricultural buildings is still common. Before any roofing work begins on a building constructed before 2000, it is essential to check whether asbestos-containing materials are present. Removal must be carried out by a licensed contractor before new roofing can be installed. This is not optional and failure to address it correctly creates serious legal liability.
Modern fibre cement sheeting (asbestos-free) is a viable and cost-effective replacement, particularly on agricultural buildings where a heavy tile covering would exceed structural capacity.
Pitched commercial roofs on retail premises, office conversions and public-facing buildings are often tiled or slated. The considerations are similar to domestic pitched roofs in terms of materials, but the access requirements and the need to work around business hours add complexity.
On a re-roof of a tiled pitched commercial roof, typical costs run from £60-£120 per square metre installed, depending on the tile or slate specified, the pitch and the roof complexity. Natural slate commands a higher price than concrete interlocking tiles, but outlasts them significantly.
Before committing to any commercial roofing contractor, there are specific questions worth asking. The answers reveal a great deal about the quality of the proposal.
Getting clear answers to all of these before work starts prevents disputes and disappointment at the end of the job.
A like-for-like replacement of a commercial roof covering using the same material generally does not require planning permission, but there are exceptions. If the building is listed, in a conservation area, or if the replacement changes the appearance of the roof - for example, replacing profiled metal sheeting with a different profile or colour - you should check with the local planning authority before proceeding.
Building regulations apply to commercial re-roofs where the work involves a change to the thermal performance of the roof. In practice, if you are stripping a flat roof back to the deck and reinstating with new insulation and covering, the new insulation specification must meet current Part L requirements. A competent contractor will flag this and specify accordingly. It is not optional.
Prices depend heavily on roof type, access difficulty, material specification and the condition of the existing structure. As a broad guide based on current UK market rates:
These figures do not include scaffold, structural repairs, asbestos removal or out-of-hours working, which can add significantly to the final cost. Always get a breakdown that separates materials, labour, access and disposal so you can see where the money is going.
A repair is always cheaper in the short term. Whether it is better value depends on the age and overall condition of the existing covering. A 10-year-old felt roof with one failed seam is an obvious candidate for repair. A 25-year-old felt roof with widespread blistering, cracked upstands and failing flashings at every penetration is likely to continue failing at different points even after repairs - at which point the cumulative cost of repeated call-outs approaches or exceeds a full replacement.
A condition survey before any significant expenditure on repairs is the sensible starting point. It costs a little time but gives you the information to make a decision you will not regret two years later.
For commercial roofing work in Cromer and across North Norfolk, call North Walsham Roofers to arrange a condition survey and written specification for your building.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
