Thetford Roofers provides commercial roofing in Mundford and across the surrounding area, working on industrial units, retail premises, warehouses, and agricultural buildings.
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Material choice is one of the most consequential decisions in any commercial roofing project. Get it right and you have a roof that performs reliably for decades with manageable maintenance. Get it wrong - or let a contractor choose purely on cost - and you can find yourself paying for remedial work well before the roof has reached the end of its intended life.
This page covers the main materials used on commercial roofs in Mundford and the surrounding area, including Thetford, Watton, Brandon, Mildenhall, Methwold, and Feltwell, with honest notes on where each works well and where it falls short.
Built-up felt remains one of the most widely used systems on flat and shallow-pitch commercial roofs. A torch-on system uses layers of modified bitumen felt, each torched to the layer below to create a bonded, monolithic waterproofing layer. The top surface is typically finished with mineral aggregate or a polyester-reinforced cap sheet.
Pros: Familiar to most contractors, widely available, straightforward to repair. A correctly installed three-layer torch-on system on a sound deck performs well and is compatible with most existing substrates.
Cons: Performance varies enormously with installation quality. Inadequate lap widths, insufficient torching, or a poorly prepared substrate all shorten service life significantly. Torch-on felt is also vulnerable to UV degradation if the top surface is not properly finished, and large roof areas that flex with temperature change can cause splits at laps over time.
Typical installed cost for torch-on felt on a commercial flat roof in the UK currently runs from around £60 to £100 per square metre, depending on deck condition, access, and the number of layers specified.
EPDM (ethylene propylene diene monomer) is a synthetic rubber sheet membrane widely used on flat commercial roofs. It is available in large sheet widths, which means fewer seams and fewer potential leak points on a wide roof area. It can be installed fully adhered, mechanically fastened, or ballasted with gravel.
Pros: EPDM handles thermal movement very well because rubber is inherently flexible. It is UV-stable, resists frost and moderate ponding, and is straightforward to repair with purpose-made adhesives and tape if a seam or puncture fails. Large sheet sizes suit wide, open commercial roof decks efficiently.
Cons: EPDM must be installed correctly for seams and edge details to hold. A poorly made cold-glued seam is a long-term leak risk. It is also less resistant to puncture from foot traffic than some other systems, so protection boards around plant and access routes are sensible. Some building owners find the plain black appearance an issue on visually prominent roofs, though this is a minor practical consideration.
EPDM typically costs from around £70 to £110 per square metre installed on a commercial building, with the range reflecting deck preparation, edge detailing complexity, and access requirements.
Profile steel roofing - including box profile and standing seam - is the standard choice for industrial units, agricultural buildings, and commercial warehouses where the structure is designed to carry the sheeting directly. It is fast to install on a large roof area, relatively lightweight, and available in a range of coatings and colours.
Pros: Well-suited to large, open roof areas with a structural steel or timber purlin frame. A modern polyester or plastisol coating on a steel sheet is durable when fixings are maintained. Box profile is also straightforward to add insulated liner trays to, which improves thermal performance and internal appearance in one operation.
Cons: Fixings are a persistent weak point. Self-drilling screws with EPDM washers need checking periodically - they corrode, the rubber deteriorates, and a loose or failed fixing is an immediate water entry point. Laps between sheets also need a compatible sealant that remains flexible; rigid sealants crack with thermal movement and fail. Steel sheeting also conducts sound - rain and hail noise inside an uninsulated metal-roofed building can be significant.
Re-sheeting a commercial roof with box profile typically costs from around £30 to £70 per square metre for the sheeting work alone, with insulated liner panels adding to that figure. Access, the condition of the existing purlins, and the pitch of the roof all affect the final cost.
Cold-applied liquid membranes are used where roof geometry is complex - numerous penetrations, unusual upstand shapes, or heavily trafficked flat roofs where a seamless waterproofing layer is advantageous. They are brushed or rolled onto the prepared substrate and cure to form a continuous, flexible waterproofing layer.
Pros: Genuinely seamless, so there are no lap joints to fail. They conform to irregular shapes and penetrations without separate flashings at every detail. Some systems bond well to existing felt or concrete substrates, making them useful for overlay repairs where strip-off is not practical.
Cons: Surface preparation is critical and time-consuming. Any contamination, moisture in the substrate, or inadequate primer causes adhesion failure. Application thickness needs to be consistent - thin spots are weak spots. Liquid systems also have a shorter usable life per applied coat than a full felt or EPDM replacement, so they are better suited to specific remedial applications than to primary waterproofing on a large new build.
On commercial flat roofs, insulation is almost always part of the specification - either because building regulations require it or because energy costs make it worthwhile. The main options are polyisocyanurate (PIR) boards, mineral wool, and expanded polystyrene (EPS).
PIR boards offer the highest thermal resistance per millimetre, which matters when roof build-up depth is constrained by parapet heights or door thresholds. Mineral wool is more commonly used in metal roof systems between liner and outer sheet. EPS is lower cost but bulkier for the same thermal performance.
When replacing a flat roof, it is worth asking the contractor to specify the insulation type, thickness, and resulting U-value. Building regulations typically require commercial roofs to achieve a U-value of 0.18 W/m²K or better in a replacement situation, though this should be confirmed against current approved documents for the specific building type.
Roof lights are a practical part of many commercial roofs, providing natural light to internal spaces. The main options are polycarbonate (multiwall or solid), and mineral or safety glass in a frame system. Polycarbonate degrades over time - yellowing and embrittlement are common after 15-20 years - and the kerb seal is a known leak point. Glass roof lights are more durable and maintain their light transmission, but are heavier and more expensive to install and replace.
When specifying replacement roof lights, ask for the size, framing system, and U-value. An old single-skin polycarbonate panel replaced with a modern double-skin unit improves thermal performance noticeably in a heated building.
We cover Mundford and the wider area including Thetford, Watton, Mildenhall, Methwold, Feltwell, and Brandon. Call us to discuss the right system for your commercial building and get a written specification before any work starts.
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Call any time. Calls are answered day and night and passed straight to our roofers.
