Newmarket Roofers provides commercial roofing services in Sawston and the surrounding area, including flat roof repairs and replacements, leadwork, guttering and full re-covers on retail, industrial and office buildings.
When a commercial roof starts causing problems, the first question most business owners and property managers ask is whether to repair it or replace it. The honest answer depends on the age of the roof, the system it uses, how widespread the damage is, and what the building is worth to you over the next ten or twenty years. There is no single rule that applies to every situation, but there are clear signals that point you one way or the other.
Commercial roofing takes in a wide range of building types - retail units, office blocks, warehouses, agricultural buildings and light industrial units. The roof systems on these buildings differ considerably from domestic properties. Large flat sections, box gutters, profiled metal sheets, roof lights and plant penetrations are all common features, and each one is a potential failure point if not maintained or installed correctly.
We carry out flat roof replacements, repairs, re-covers, leadwork, guttering work and full new-build roofing on commercial properties in and around Sawston, working back from Newmarket and covering the wider area including Cambridge, Ely and Burwell.
Repair is the right call when the problem is localised and the rest of the roof is structurally sound. A split seam on an EPDM membrane, a failed flashing at a parapet wall, a cracked or slipped tile on a pitched section, or a blocked outlet causing localised ponding - these are all problems that can be fixed without replacing the whole roof, provided the underlying deck and insulation are undamaged.
Felt roofs that are less than ten years old and have a single failure point at an edge or penetration are usually good repair candidates. EPDM membranes are particularly repairable - patches bond well to the existing membrane if the surface is clean and the repair is done with compatible adhesive and tape, not a bead of silicone sealant (which is not a commercial roofing repair, whatever it looks like from ground level).
Typical commercial roof repairs range from around £150 to £600 for straightforward single-point fixes, rising to £1,000 or more for larger patched sections or box gutter relining. These are indicative UK figures - the actual cost depends on access, extent and materials.
Replacement starts to make more sense when repairs become a pattern rather than a one-off. If you are calling a roofer out every eighteen months, the cumulative cost of those visits - and the disruption to your business each time - will often exceed the cost of a proper replacement within a few years.
Other signs that repair is no longer the right answer:
A re-cover - where a new system is laid over the existing one without full strip-out - is sometimes a middle option worth considering. It avoids the cost and waste of stripping, but it is only suitable when the existing deck is sound and the additional weight is within the structural limits of the building. A contractor should check both before recommending it.
Torch-on felt, correctly installed in three layers with proper upstands and edge detailing, typically performs well for fifteen to twenty years. A single-layer felt job will rarely last that long. If you are repairing a single-layer system repeatedly, replacement with a properly specified three-layer felt or EPDM system will usually resolve the cycle of problems.
EPDM is increasingly specified for commercial flat roofs because it handles building movement and temperature variation well. It is also easier to repair cleanly when damage does occur. On a large commercial roof, EPDM can be installed in very wide sheets, reducing the number of seams and therefore the number of potential failure points.
Typical replacement costs for a commercial flat roof run from around £70 to £120 per square metre for a torch-on felt system, and £80 to £140 per square metre for EPDM. Insulation, drainage work and access will affect the final figure.
On warehouses, agricultural buildings and industrial units with profiled metal roofing, the same principle applies. Localised rust, loose fixings and failed ridge cappings can often be repaired or replaced in sections. But if sheets are corroding across a wide area or the fixings are failing systematically, over-sheeting or full replacement is usually more cost-effective than repeated patching.
Over-sheeting - fixing new metal profile sheets over the existing ones - avoids disposal costs and reduces labour time compared to a full strip. It adds weight to the structure, so the purlins and framework must be checked first. Ask any contractor to confirm they have assessed the existing structure before recommending this route.
Leadwork is a separate consideration on many commercial buildings - around parapet walls, roof lights, step flashings and chimneys on older office or retail buildings. Lead that has cracked due to thermal fatigue (expansion and contraction over many years) cannot be reliably repaired with sealant. It needs to be cut out and replaced in properly sized sections fixed with clips, not wedged and pointed in mortar. Small sections of failed lead are almost always worth replacing rather than patching.
The decision between repair and replacement should be based on a proper inspection, not a quote written from a photograph or a description over the phone. A contractor who recommends replacement without getting on the roof and checking the deck, the insulation and the drainage has not given you enough information to make a sound decision.
Ask any contractor: what is the condition of the deck? Is the insulation wet? Is the drainage adequate? If they cannot answer those questions, ask them to go back up and look properly before you sign anything.
We cover commercial properties in Sawston and the wider area including Newmarket, Cambridge, Ely and Histon. Call us to arrange a proper roof survey so you get an honest assessment, not just the answer that suits the contractor's schedule.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
