Dereham Roofers carries out commercial roofing in Easton and the surrounding area, covering warehouses, industrial units, retail premises and office buildings of all sizes.
A failing commercial roof is not just a maintenance headache. It puts stock, equipment, staff and your business's reputation at risk. Dereham Roofers works with business owners and facilities managers in Easton and nearby to keep commercial roofs watertight, properly drained and structurally sound. We handle flat roof replacement, profile metal sheeting, roof repairs, cladding and commercial guttering on a wide range of building types.
Every job is different, and we plan our work around your trading hours where possible to keep disruption to a minimum. Whether you operate a warehouse on a tight schedule or a retail unit that cannot afford to close, we aim to agree a programme of work before we start so you know what to expect.
This is the angle most businesses ignore until the damage is serious. A commercial roof can be failing for months or even years before it becomes obvious from inside the building. By the time water is coming through the ceiling, the underlying structure has often already suffered. Knowing what to look for early can save a considerable amount of money.
A flat roof is not truly flat. It is designed with a slight fall, typically a minimum of 1:80, so rainwater runs to outlets and drains away. When water sits on the surface for more than 48 hours after rainfall, the fall has failed or the outlets are blocked. Standing water is heavy, it accelerates the breakdown of felt and EPDM membranes, and it freezes in winter, forcing its way into small gaps. If you can see puddles from an upstairs window or from a mezzanine, that roof needs inspection.
Ponding is one of the most common causes of premature flat roof failure on commercial buildings. It rarely fixes itself. Over time the weight causes the deck below to bow, which makes the ponding worse, which causes more damage. The cycle is predictable and avoidable with early action.
On a felt flat roof, blistering appears as raised bubbles in the surface. This happens when moisture becomes trapped beneath the felt layers and turns to vapour as the roof heats up. The bubbles weaken the membrane and eventually split open, creating an entry point for water. On EPDM rubber roofs, cracking at seams or around flashings is the equivalent problem.
Splits and cracks are not always visible from the ground. A roof that looks intact from a distance can have multiple breaches when inspected up close. If your building is more than ten years old and the roof has never been surveyed, that is a risk worth addressing.
Flashings seal the junction between the roof membrane and any vertical surface: parapet walls, roof lights, pipe penetrations, plant equipment bases. They are typically the first point of failure on any commercial roof. Lead and aluminium flashings can pull away from the wall as the building moves, mortar joints crack, and sealant applied as a temporary fix shrinks and lifts within a few years.
Water that enters through a flashing failure travels horizontally before it drops, so the visible damp patch inside the building is often a metre or more away from the actual breach. This makes flashing failures particularly difficult to trace without a proper inspection. On any commercial building in Easton or the surrounding area, we recommend checking flashings as part of any routine maintenance visit.
If the roof deck itself has absorbed water over a long period, the structural boards or insulation beneath the membrane begin to rot or compress. The surface of the roof starts to feel soft underfoot, or you can see visible depressions and waves in the profile. This is a more serious problem than a membrane failure alone, because the deck needs to be replaced before any new covering can be laid.
A sagging deck is also a safety issue. Commercial roofs are accessed for maintenance by engineers and contractors. A deck that is not structurally sound is a hazard that should be reported and addressed promptly.
On large commercial buildings, gutters carry a significantly higher volume of water than on a domestic property. Industrial and retail units typically have valley gutters running between roof sections, box gutters built into the structure, or fascia gutters along the eaves. When these block with debris, overflow is rapid and the water has nowhere to go except back under the roofline or down the external walls.
Blocked gutters also cause localised saturation of the fascia and soffit boards, which then rot and allow water into the roof structure. Commercial gutter repairs and regular clearance are a straightforward way to prevent damage that can cost many times more to put right.
Profile metal sheeting is widely used on warehouses and industrial units. It is a practical, cost-effective roofing system, but it requires attention as it ages. Surface rust begins as discolouration and pitting, often around fixings and at laps where the sheets overlap. Left untreated, corrosion spreads beneath the sheet surface and the fixing holes enlarge, allowing water ingress and reducing the sheet's structural integrity.
A corroded metal roof does not always need full replacement. In many cases, individual sheets can be replaced, fixings renewed and the surface treated or overcoated. Getting a proper assessment early is important because the longer corrosion is left, the more sheets are typically affected.
Inside the building, the signs of a failing commercial roof include watermarks or tide marks on ceiling panels or plasterboard, rust stains on steel purlins or structural members, efflorescence (white salt deposits) on internal brickwork, condensation on windows or structural steelwork, and a persistent damp smell that does not improve in dry weather.
Any of these should prompt a roof inspection. They are not always catastrophic in isolation, but each one indicates that water is getting into the building envelope somewhere it should not be.
Most commercial roof failures do not happen suddenly. They develop from a combination of age, deferred maintenance and design details that were never quite right. Understanding the causes helps you make better decisions about repair versus replacement.
Felt flat roofs have a typical service life of 15 to 25 years depending on the number of layers, the quality of the original installation and how well the roof has been maintained. EPDM rubber membranes tend to last longer, often 30 years or more under good conditions. Profile metal roofing can last 30 to 40 years with correct maintenance but is vulnerable to corrosion if protective coatings are not maintained.
Beyond a certain age, patching becomes less cost-effective than replacement. A roof that is regularly leaking and has had multiple patch repairs over several years is usually telling you it needs a full strip and re-cover rather than another temporary fix.
A significant proportion of commercial roof failures can be traced back to errors in the original installation. Common problems include insufficient falls designed into the roof so water never drains properly, inadequate number of outlets for the roof area, flashings dressed incorrectly or fixed with the wrong materials, insulation boards laid without adequate vapour control, and metal sheets fixed with too few screws or with screws that are the wrong specification for the profile.
When a commercial roof has a recurring problem in the same area, poor original workmanship is often the underlying cause. Repairing the symptom without addressing the root problem means the repair is unlikely to last.
Commercial roofs are out of sight and easy to forget. Many business owners and landlords only discover a problem when water comes through the ceiling. A straightforward maintenance programme, including clearing outlets and gutters, checking flashings and inspecting the membrane surface twice a year, catches most problems before they become expensive. A small repair to a lifting flashing costs a fraction of what it costs to replace saturated insulation boards and re-cover the entire section of roof.
On commercial buildings, the roof is accessed regularly by engineers maintaining air conditioning units, extraction systems, solar panels and communication equipment. Foot traffic on a flat roof without proper protection boards damages the membrane. Equipment fixings that penetrate the membrane without proper flashing details create leak points. Over time, the accumulation of these small penetrations and surface scuffs adds up to significant water ingress risk.
For commercial flat roofs, the two systems we work with most are reinforced felt (built-up felt) and EPDM rubber membrane. The right choice depends on the size and shape of the roof, the budget, and how the building is used.
A built-up felt system uses multiple layers of bitumen felt, typically three layers, bonded together to form a waterproof covering. The top layer is usually finished with mineral chippings or a cap sheet with a granule surface. It is a well-understood, widely used system that is straightforward to repair if a section is damaged. On a new installation with a correctly designed fall and good detailing at upstands and flashings, a quality felt roof performs reliably for many years.
Flat roof replacement on commercial buildings in this part of Norfolk typically costs in the region of £70 to £120 per square metre for a standard built-up felt system, depending on the number of layers, deck condition and access requirements. These are general figures and the actual cost for any specific roof depends on a proper survey.
EPDM (ethylene propylene diene monomer) is a single-ply rubber membrane that has become a popular choice for commercial flat roofs. It is lightweight, flexible and handles temperature extremes well without becoming brittle. The membrane comes in large sheets that can be bonded directly to the deck or mechanically fixed, with far fewer seams than a felt system. Fewer seams mean fewer potential leak points.
EPDM is particularly suitable for roofs with roof lights, plant penetrations or irregular shapes because the membrane can be dressed around complex details. It is also suitable for re-covering over an existing deck if the deck is sound, which can reduce costs compared with a full strip.
Profile metal sheeting is cost-effective over large spans, quick to install and durable when maintained correctly.
We carry out repairs to existing metal roofs, including replacing individual sheets, re-fixing loose sheets and renewing fixings where corrosion has caused them to fail. Where a metal roof is beyond economic repair, we can carry out a full replacement or, in appropriate cases, over-roof the existing sheets with a new profiled system, avoiding the cost and disruption of a full strip.
Cladding to the walls of industrial and commercial buildings is typically the same profiled steel sheeting fitted vertically. Damaged cladding panels can admit water, reduce thermal performance and create a security risk. Individual panel replacement is usually straightforward and avoids the need to replace an entire elevation.
Large commercial buildings have guttering that handles significantly more water than domestic systems. Valley gutters between roof pitches, box gutters built into the structure and high-level parapet gutters are all common on warehouses and retail premises. These systems are more difficult to access and maintain than domestic gutters, which is why blockages and damage are often discovered late.
Blocked commercial gutters cause overflow that saturates external walls and, in the case of valley and box gutters, can back up under roof sheets or flashings. We carry out commercial gutter repairs, replacement of damaged sections, and clearing and jetting of blocked downpipes. For buildings where gutter maintenance has been neglected, we can assess the condition of the full system and advise on what needs replacing versus what can be repaired.
Commercial roofing work requires planning to avoid unnecessary disruption. Before starting, we agree the programme with you, including which areas of the roof will be worked on each day, how access will be managed and what noise or debris controls are in place. For retail premises and occupied office buildings, early morning starts, weekend working or phased programmes may be appropriate.
We cover Easton and the surrounding area including Dereham and Norwich. If your commercial premises are in this part of Norfolk and you have a roof that is giving you concern, call us to arrange a survey.
Choosing the right contractor for a commercial roofing job is important. The questions below are worth asking any contractor you are considering.
A contractor who cannot or will not answer these questions clearly is worth treating with caution. A written specification protects you as much as it protects the contractor.
If you have noticed any of the warning signs described on this page, or if your commercial roof is more than 15 years old and has never been properly inspected, call Dereham Roofers to arrange a roof survey. We cover Easton and the wider Norfolk area including Dereham and Norwich, and we can advise you on whether repair or replacement is the more cost-effective option 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.
