Dereham Roofers carries out commercial roofing in Mattishall and the surrounding area, covering flat roof replacement, profile metal sheeting, cladding, guttering and repairs on warehouses, industrial units, retail premises and office buildings.
Commercial roofing is a different discipline to domestic work. The roof areas are larger, the materials differ, the loading calculations matter, and the consequences of getting it wrong - a leaking warehouse, a closed retail unit, stock or machinery damaged by water - are far more serious than a damp bedroom ceiling. A good commercial roofer understands all of that before work begins.
On a typical commercial job we handle flat roof replacement or overlay, profile metal sheet roofing, built-up felt systems, EPDM rubber membrane installation, ridge and wall cladding, rainwater guttering and downpipes, and repairs to any of the above. We work on warehouses, light industrial units, farm buildings used commercially, retail premises and office blocks across Mattishall and throughout Norfolk.
Work is planned around your operating hours wherever that is practical. A business that needs to stay open during roofing work is not unusual, and access, noise and debris management are things we factor in at the planning stage rather than on the day.
This is the angle most business owners want before they commit to a quote. The roofing industry does not always volunteer the full picture, so here is a straightforward breakdown of the main systems used on commercial buildings, with their genuine advantages and limitations.
Steel or aluminium profiled sheets - sometimes called corrugated or box-profile sheets - are a widely used material on industrial and agricultural commercial roofs. They are fast to install, relatively affordable per square metre, and can span large areas without complex jointing. A quality coated steel sheet, properly fixed, can last 25-40 years before the finish degrades enough to cause problems.
The honest limitations: metal roofs conduct heat, which means a warehouse with no insulation layer below the sheet will be cold in winter and very hot in summer. Adding an insulation quilt or a liner sheet brings that under control but adds to the cost. Fixing screws are the most common failure point - the neoprene washers that seal each screw hole harden and crack over time, letting water track down into the building. A periodic inspection and screw replacement programme is far cheaper than waiting for visible leaks to develop.
Profile sheets are also susceptible to condensation on the underside if there is no vapour control layer. On older industrial buildings, condensation drip is frequently misdiagnosed as a roof leak when the sheet itself is watertight. Getting that diagnosis right at the start saves money.
Typical installed cost for profile metal sheeting ranges from around £25 to £55 per square metre depending on sheet gauge, profile type, insulation specification and access requirements. Larger roofs generally come in at the lower end of that range per square metre.
EPDM (ethylene propylene diene monomer) is a single-ply rubber membrane used on flat and very low-pitch commercial roofs. It has become the preferred flat roof system for smaller commercial buildings because it is flexible, resistant to UV degradation, handles temperature extremes well, and is lighter than built-up felt systems. A correctly installed EPDM membrane typically performs for 20-30 years before replacement becomes necessary.
The main advantage over traditional felt is that EPDM comes in large sheets with very few seams. Most flat roof failures occur at joints and seams, so reducing the number of them reduces the risk. On a flat roof covering a small office or retail extension, it is often possible to use a single sheet with no joins at all.
The limitations are worth knowing. EPDM is not as rigid as metal or felt, so it relies heavily on the quality of the deck beneath it. If the existing roof deck - typically plywood or OSB - is rotten or uneven, it needs replacing before the membrane goes on. Skipping that step is a false economy. EPDM is also not the right choice for roofs with significant foot traffic, because repeated walking will eventually cause surface damage; for a roof terrace or a flat roof that needs regular access, a more durable protection layer should be considered.
Installed cost for EPDM on commercial flat roofs typically runs from around £60 to £100 per square metre, depending on insulation requirements, deck condition and roof complexity. A roof that needs the deck replaced before the membrane is laid will sit toward the top of that range.
Traditional three-layer built-up felt - a base layer, intermediate layer and a mineral-finish cap sheet, torch-applied or cold-bonded - has been the standard flat roofing material for commercial buildings for decades. It remains a valid choice. The material cost is lower than EPDM, and any roofing contractor working in commercial flat roofing will be familiar with it.
The honest picture: felt has a shorter service life than EPDM and is more vulnerable to UV degradation and thermal cracking over time. The top mineral surface can blister in prolonged heat and become brittle in very cold conditions. A quality three-layer system installed correctly can give 15-20 years of reliable service, but it will need attention sooner than a well-installed EPDM membrane.
Where felt remains genuinely competitive is on repairs and partial overlays. If a large commercial flat roof is in reasonable overall condition but has localised failures - cracked seams, lifted edges, blistered sections - a targeted felt repair is often better value than a full membrane replacement. That judgement requires an honest survey rather than a blanket recommendation either way.
Thermal insulation in a commercial roof is not purely a roofing question - it directly affects heating and cooling costs for the building occupier. On a new commercial roof, the choice of insulation board (PIR, EPS, mineral wool) and its thickness determines both the U-value achieved and the overall build-up depth.
Current building regulations require a U-value of 0.18 W/m2K for new commercial flat roofs and 0.16 W/m2K for new pitched metal roofs. Those figures are not aspirational - they are the minimum required for a new installation or a full replacement. A reroofing project that simply lays new material on top of an old uninsulated deck without addressing the U-value will not comply with current regulations and may cause problems if you sell or redevelop the property.
Upgrading insulation at the point of reroofing costs relatively little as a proportion of the overall project. Retrofitting it afterwards - or having to redo non-compliant work - is expensive. Ask any contractor quoting your job to confirm the proposed U-value and how they intend to achieve it.
Wall cladding on commercial and industrial buildings - the vertical profiled sheeting on the gable ends and sides of a warehouse or factory unit, for example - is closely related to roof sheeting in both material and fixing method. It is often replaced or repaired at the same time as the roof, both for practical access reasons and because deterioration usually happens at a similar rate.
Cladding failure shows up as corrosion at the bottom of sheets (where water and debris collect), loose or missing fixings, failed mastic sealant around openings and penetrations, and faded or peeling coating on older steel sheets. Recoating corroded or faded sheets in situ is possible in some cases and is considerably cheaper than full replacement.
On older commercial buildings, particularly those built in the 1970s and 1980s, the insulation layer behind the cladding may contain materials that require specialist disposal. If you are planning cladding replacement on a building of that era, ask the contractor to identify what is behind the existing sheets before work begins. Dealing with that question early avoids surprises that delay a project.
Guttering on a commercial building works harder than domestic guttering. The roof areas are larger, the flow volumes during heavy rain are higher, and the gutters are typically further off the ground - making blockages easier to miss and harder to clear. A blocked or overflowing gutter on a warehouse can direct water against the wall cladding, into fixings, and eventually through the building fabric.
Common failures on commercial guttering include: sagging box gutter sections where the falls have settled or been poorly set originally; split or cracked UPVC sections on older retail and office buildings; failed mastic joints on steel box gutters; and blocked or collapsed downpipes that cause the gutter to back up and overflow.
Box gutters - the large internal gutters that sit within the valley of a double-span industrial roof - are a particular source of problems. They are often lined with felt or a single-ply membrane, and when that lining fails, water tracks along the inside of the building structure before appearing as a drip inside the unit. The point where the drip is visible inside is rarely directly below the point of failure.
Gutter repairs and replacement are usually straightforward if caught early. Left until the point of active flooding or visible structural deterioration, the remedial work becomes significantly more involved. On any commercial building, an annual gutter inspection and clearance is a practical step that costs very little relative to the water damage it prevents.
A repair on a commercial roof should begin with a proper inspection, not an immediate patch. The visible point of a leak is often not the point of water entry. Water travels under membranes, along purlins, down internal steelwork, and can appear inside a building metres from the actual defect. A contractor who goes straight to the nearest seam and applies sealant without checking the whole area is likely to be back before long.
Before agreeing to a repair, ask the contractor to explain where they believe the water is entering and why. If they cannot give you a clear answer, ask for a more thorough survey before any work begins. On complex roof failures - particularly on older built-up felt roofs or on profiles with multiple penetrations for rooflights, ventilation and pipework - a camera inspection or water test may be needed to locate the source accurately.
Repair costs vary considerably. A simple seam repair or screw replacement on a profile metal roof might be a few hundred pounds. A larger felt repair involving stripping back sections and replacing decking could be several thousand. Any quote that does not specify exactly what is being done, in what area, with what materials, should be queried before you sign off on it.
Commercial roofing prices in this part of Norfolk are affected by a number of factors beyond the roof area itself. Access is one of the biggest variables - a warehouse with no hard standing for a scaffold or a MEWP (mobile elevating work platform) will cost more to work on than one with clear surrounding access. Roof pitch, fall and complexity all affect labour time. The condition of the existing structure affects what materials and preparation are needed underneath the new covering.
When comparing quotes for a commercial roofing project, the area measured should be consistent between contractors. Some quote on plan area (the flat footprint of the roof), others on actual raking area (which accounts for slope). On a pitched profile metal roof, those two figures can differ by 20-30%. Ask each contractor which basis they are using.
Lead times on materials - particularly profiled steel sheets in specific colours or gauges - can be two to four weeks from order to delivery. Factor that into your planning if the project is time-sensitive, especially if existing damage is allowing water into the building.
For commercial roof replacement in the Mattishall area and across Norfolk, call us to arrange a site survey and a detailed written quotation.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
