North Walsham Roofers carries out commercial roofing repairs, replacements and new installations for businesses and landowners in Bacton and the surrounding North Norfolk villages.
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Commercial roofing covers any roofing work on a building used for business, trade, agriculture or industry. That includes flat-roofed retail units, office buildings, farm stores, workshops, barns, industrial units and any outbuilding attached to a commercial premises. The scope of the job is wider than a domestic repair, the materials are different, and the consequences of getting it wrong are greater - a failed roof over a working building can mean stock damage, health and safety issues and lost trading time.
Work falls into three categories: repairs to an existing roof that is otherwise sound, a full replacement where the covering has reached the end of its serviceable life, and new-build or extension installations where there is no existing roof at all. Each requires a different approach to specification, materials and programme.
Many single-storey commercial buildings carry a flat roof or a very low-pitch roof. These are the roofs that take the most punishment from standing water, frost and wind-lifted edges, and they are the ones most likely to need attention on a commercial premises. Understanding the material options available is the most useful thing a building owner can do before calling anyone in.
Torch-on felt, sometimes called built-up felt or hot-melt felt, has been the standard commercial flat-roof covering for decades. It is applied in two or three layers using a gas torch, which bonds the layers together and to the substrate beneath. A properly installed three-layer torch-on system on a sound deck gives a serviceable life typically quoted at 15 to 25 years, though actual performance depends heavily on the quality of the installation and how well the drainage and detailing are maintained.
Pros: Widely understood, straightforward to repair, compatible with most existing substrates, cost-effective upfront. A small section of damage can usually be cut out and patched without replacing the whole roof. Cons: The seams and laps are the weakest points - water finds its way in at the edges, around outlets and wherever the felt has split or lifted. Cheaper installations may use only two layers, which shortens the lifespan considerably. Felt also adds weight to the deck, so a very old or suspect deck may need assessment before re-covering. Typical cost for a commercial torch-on flat roof is in the region of £40 to £70 per square metre installed, depending on deck condition, access and specification.
EPDM (ethylene propylene diene monomer) is a single-ply synthetic rubber membrane that is bonded or mechanically fixed to the roof deck. It has grown in popularity for commercial buildings over the past fifteen years because it is lightweight, highly flexible and comes in large sheets that reduce the number of seams - seams being where most flat-roof failures begin.
Pros: Fewer joints means fewer potential failure points. EPDM is resistant to UV degradation and handles thermal movement well, which matters on large commercial roof areas that heat up and cool down significantly with the seasons. Manufacturer product lifespans are often quoted at 50 years for the membrane itself, though actual installation quality and detailing determine whether that is realistic in practice. EPDM is also lighter than felt, putting less load on the deck. Cons: Not every roofing contractor installs it correctly - the adhesive bonding process has to be done in the right temperature range and conditions, and poor bonding leads to lifting. If a section is damaged by a sharp impact (dropped tools, fallen branch), it needs a specialist patch rather than a simple felt repair. Installed cost typically runs from £60 to £100 per square metre on a commercial building, with the variation driven by roof size, access difficulty and deck preparation needed.
Thermoplastic membranes (TPO and PVC) are hot-air welded at the seams rather than bonded with adhesive. The welded seam, when done correctly, is actually stronger than the membrane itself, which is a significant advantage on large flat roofs. These systems are common on larger industrial and retail buildings.
Pros: Excellent seam integrity when welded by a competent operative. Good resistance to puncture and chemical exposure. White or light-coloured membranes reflect heat, which can reduce cooling loads inside the building in summer. Cons: Requires specialist welding equipment and a trained operative - not every local contractor carries this. PVC can become brittle at the seams over time if the plasticisers migrate out, which is less of an issue with modern formulations but worth asking about. TPO is generally considered more durable in this respect. Cost is broadly similar to EPDM, from £65 to £110 per square metre installed on a typical commercial building.
Agricultural buildings, rural workshops, storage barns and some older commercial premises often carry pitched roofs rather than flat ones. The materials used are different from domestic pitched roofing, and the priorities are different too.
Large agricultural and industrial buildings are typically covered with profiled metal sheeting (steel or aluminium) or older fibre cement (Eternit-style) sheets. Older asbestos-containing cement sheets are still present on some rural buildings. If you are dealing with a building that was constructed before the mid-1980s and has corrugated roof sheets, there is a reasonable chance the original sheets contain asbestos, and any work involving them must be carried out in compliance with current regulations - that means testing before any disturbance, and licensed removal if the material is in poor condition.
Replacement sheeting in profiled steel is cost-effective on a large span, typically £25 to £55 per square metre for the sheeting and fixing alone, but access (scaffolding or MEWP hire), removal and disposal of old sheets, and any structural purlin repairs add substantially to the final cost. Always get a breakdown of what the quote includes.
Older commercial buildings and converted farm premises sometimes carry concrete or natural slate roofs. The approach here is largely the same as for domestic work - individual slipped or cracked tiles can be replaced, but widespread failure of fixings or a large number of broken units usually makes a full strip and re-tile the more economical long-term choice. On a commercial building, factor in the cost of scaffolding, which is not optional on any pitched roof above single-storey height.
On flat roofs, the most common problems are failed laps at the felt seams, lifted edges where the membrane has not been properly dressed into the upstand or parapet, and blocked or poorly positioned drainage outlets that leave standing water. Standing water accelerates the degradation of any membrane, and on a flat roof that has even a slight deflection in the deck, pooling is almost inevitable unless the outlet positions account for it.
On pitched commercial roofs, the problems are usually fixing failure on older sheets, cracked or slipped tiles, failed ridge or hip mortar, and lead or code flashing failures at abutments and around rooflights. A missing or loose ridge tile on a working building is not just a cosmetic problem - it exposes the ridge board and, on an older building, the roof structure below to water ingress that can go unnoticed for months.
Felt blistering on flat roofs is often mistaken for structural failure but is usually caused by moisture in the deck at the time of installation. The blister itself is not always leaking, but it does indicate that the membrane is no longer fully bonded and will eventually fail at that point. Whether to patch or replace depends on how widespread the blistering is and the overall condition of the deck underneath.
Before you accept any quote for commercial roofing work, there are practical questions worth putting to every contractor you speak to. These are not trick questions - any experienced roofer will have straightforward answers.
Commercial roofing work is subject to building regulations in ways that domestic work sometimes is not. A straightforward like-for-like repair usually falls outside the regulations, but a full replacement, particularly one that changes the thermal performance of the roof, may require a building regulations application and an inspection. The relevant requirement is Part L of the building regulations, which sets minimum standards for the thermal performance of the building envelope.
In practice, this means that when you replace a flat roof on a commercial building, you may be required to upgrade the insulation at the same time. The cost of adding insulation to a flat roof during a replacement is much lower than doing it as a separate job later - so even where it is not strictly required, it is often worth doing. The insulation can be installed above or below the deck depending on the system specified, and the choice affects the overall build-up thickness and weight loading on the structure.
Scaffolding on a commercial building in active use needs to be planned carefully. On a retail unit or business premises, a scaffold that blocks a customer entrance or delivery access causes real commercial harm. A mobile elevated work platform (MEWP, commonly called a cherry picker) is sometimes the better option for repair work where the area involved is limited, as it can be positioned more flexibly and removed at the end of each working day.
On larger replacement projects, a temporary weathering system (a scaffold-mounted roof covering that keeps the building watertight while the permanent roof is stripped and replaced) is sometimes necessary. This adds cost but eliminates the risk of rain damage to the interior during the works. Whether it is needed depends on the size of the roof, the programme and the time of year.
There is no single best material for a commercial flat roof. The right choice depends on the size of the roof, the structural condition of the deck, the drainage layout, the level of foot traffic the roof needs to withstand (for maintenance access), and budget. A large roof with complex drainage and multiple service penetrations generally benefits from a welded single-ply system. A smaller roof on a straightforward deck, where a reliable local contractor is available for future maintenance, is often well served by a quality torch-on felt system at lower upfront cost.
EPDM sits between the two in cost and is particularly well suited to roofs with awkward detailing, because the membrane is flexible enough to dress neatly into complex upstands and corners without the need for multiple heat-welded details. On a building in Bacton where access for future maintenance may be less straightforward than in a town centre, choosing a material that is durable and easy to inspect and patch is worth the extra thought at the specification stage.
The honest answer to "which is best" is: specify the material that suits the building, not the one that suits the contractor's preferred method. Ask any contractor tendering for your work why they are recommending what they are recommending, and if they cannot give you a clear answer, that tells you something useful.
To give you a realistic sense of what to budget, here are typical price ranges for commercial roofing work in North Norfolk. These are indicative figures for planning purposes and actual quotes will vary based on site-specific conditions.
Always obtain at least two itemised quotes for any commercial roofing project. A quote that is significantly lower than others is usually lower because something has been left out, not because the contractor is more efficient.
If you manage or own a commercial building in Bacton or the surrounding North Norfolk area and you have concerns about the roof, the best first step is an inspection that gives you a clear picture of what is there, what its condition is, and what the realistic options are. Call us to arrange a commercial roof survey so we can give you an honest assessment and a properly itemised quote for any work required.
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Call any time. Calls are answered day and night and passed straight to our roofers.
