Diss Roofers provides commercial roofing services in Wymondham and across South Norfolk, covering flat roof replacement, single-ply membranes, and profiled steel sheet roofing on warehouses, offices, industrial units, and retail premises.
Call any time. Calls are answered day and night and passed straight to our roofers.
Choosing the right roofing material for a commercial building is one of the most important decisions you will make for the property. The wrong choice - or the right material installed poorly - leads to maintenance problems and costs that persist for years. This page sets out the main options available for commercial roofs, with honest notes on what each one does well and where its limitations lie.
We carry out the full job from initial survey and specification through to installation and sign-off, with work planned to minimise disruption to your business.
Most commercial buildings include at least some flat or low-pitched roof area. The options for waterproofing these surfaces have expanded considerably, and the material you choose affects both the upfront cost and how much maintenance the roof needs over its life.
Torch-on felt systems use multiple layers of bitumen-based felt, applied hot to form a bonded waterproof covering. They have been used on commercial buildings for decades and are well understood by most roofing contractors.
Pros: Lower material cost than single-ply systems. Widely available. Straightforward to repair with a targeted patch when damage is localised.
Cons: Shorter expected service life than single-ply or EPDM, typically in the range of 15-25 years depending on the specification and roof conditions. Vulnerable to ponding water over time, which accelerates breakdown of the surface layer. Seams and laps are potential weak points.
Torch-on felt remains a practical choice for smaller flat roof areas or budget-constrained jobs where the building owner accepts a shorter cycle before the next replacement.
EPDM (ethylene propylene diene monomer) is a synthetic rubber membrane that is supplied in large sheets, reducing the number of seams on the roof and therefore the number of potential failure points.
Pros: Long working life - EPDM membranes on commercial roofs typically perform for 30-50 years with minimal maintenance when correctly installed. Handles thermal movement well because of its flexibility. Resistant to UV degradation, which is a weakness of some other systems. Fully adhered or ballasted systems are both available.
Cons: Higher material cost than torch-on felt. Repairs require compatible EPDM bonding adhesive and some skill to complete properly - poorly done patch repairs on rubber membranes can fail quickly. Aesthetically, the black surface may not suit all buildings.
EPDM is increasingly specified for mid-to-large flat roof areas on commercial buildings where the owner wants a long maintenance interval and is prepared to spend more upfront.
Single-ply membranes include materials such as TPO (thermoplastic polyolefin) and PVC-based sheets. They are mechanically fixed or fully adhered to the roof deck and heat-welded at seams to form a continuous waterproof layer.
Pros: Heat-welded seams are consistently strong when done with the correct equipment and technique. Available in a range of colours, which can help with heat reflectance on south-facing roofs. Lighter than multi-layer systems, which can matter on roofs with load restrictions. Service life comparable to EPDM when correctly installed.
Cons: Higher cost per square metre than felt. Mechanical fixings through the membrane, if used, must be carefully detailed or they become entry points for water. Repairs to damaged sections require heat-welding equipment rather than a simple adhesive patch.
Single-ply systems are a strong choice for large commercial roofs where seam integrity and long-term performance are the priority. Typical installed costs for single-ply commercial flat roofing run from around £60-£120 per square metre depending on deck condition, insulation specification, and access requirements.
Profiled steel - including box profile and sinusoidal (corrugated) sheet - is the standard covering for the pitched roofs of warehouses, agricultural buildings converted to commercial use, and many industrial units. It is fixed over steel or timber purlins and designed to shed water quickly through its pitch.
Pros: Durable and low maintenance when the protective coating is intact. Lightweight relative to its span. Available in a wide range of profiles and colours. Straightforward to add insulated liner systems for thermal performance.
Cons: Cut ends and fixing points corrode if the protective coating is breached or if the correct fixings are not used. Sheet-to-sheet side laps and end laps must be correctly sealed or wind-driven rain finds its way through. Once surface rust takes hold on older sheets, localised patching has limited lifespan and a full re-sheet is usually more economical.
Re-sheeting a large industrial or warehouse roof in profiled steel typically costs £25-£60 per square metre for the sheeting work alone, with variation depending on sheet profile, thickness, coating specification, and the complexity of the roof layout. Insulation and new liner panels add to this figure.
On any commercial roof, the insulation specification matters alongside the waterproof layer. Older commercial buildings were often built with minimal roof insulation, and upgrading it at the time of a roof replacement significantly reduces heating and cooling costs. The two most common insulation materials used in commercial flat roof systems are PIR board (polyisocyanurate) and mineral wool. PIR gives a higher thermal performance per millimetre of thickness, which matters when overall roof build-up depth is constrained by existing kerbs or drainage details.
Before accepting a specification for a commercial roof, it is worth asking:
A contractor who cannot answer these questions clearly is worth being cautious about.
If you are not sure which system is right for your building, the starting point is a proper roof survey that checks the deck, the existing waterproof layer, the drainage, and the insulation. We carry out surveys on commercial buildings in Wymondham and across the South Norfolk area.
Call us to arrange a survey and get a clear picture of your options before you make any decisions.
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Call any time. Calls are answered day and night and passed straight to our roofers.
