Commercial Roofing in Norwich

How we handle commercial roofing

Commercial Roofing in Norwich

Commercial roofs take a different kind of punishment to the average house roof. Wide, flat or low-pitched spans collect standing water. Rooftop plant, extraction units and pipework create dozens of potential leak points. Foot traffic during maintenance damages membranes that were never designed for it. If your building is in Norwich or the surrounding area and you need the roof assessed, repaired or replaced, we can help.

We work on offices, warehouses, retail units, industrial sheds, schools, care homes and mixed-use blocks. The building type matters because it shapes everything: the load the structure can take, the access method needed, the insulation specification and the membrane system that will perform best over the long term.

Flat Roof Systems for Commercial Buildings

Commercial roofs are often either fully flat or very low pitched, which means water management is the central challenge. A pitch below 10 degrees cannot shed water the way a tiled roof does, so the membrane and drainage design carry all the responsibility.

The two systems we use most on commercial work are torch-on felt and EPDM rubber membrane. Each suits different situations.

• Torch-on felt (built-up felt): A multi-layer system bonded with a gas torch. The layers bond together and to the deck below, creating a durable, relatively rigid surface. A two-layer or three-layer build-up is standard on commercial roofs. The top cap sheet is typically mineral-faced for UV protection. Properly installed on a sound deck with correct falls, built-up felt is a proven, cost-effective system for large flat areas.
• EPDM rubber membrane: A single-ply synthetic rubber sheet bonded or mechanically fixed to the deck. EPDM handles temperature extremes well, staying flexible in cold weather and resisting UV degradation. It is particularly useful on roofs with awkward shapes or penetrations because it can be formed around details more easily than rigid sheet materials. Manufacturer ratings for EPDM membranes commonly quote 20 years or more, though actual service life depends on installation quality and maintenance.

We will survey the roof, check the existing deck condition, measure the falls and advise which system suits your building and budget before any work starts.

Pitched Commercial Roofing

Not all commercial buildings have flat roofs. Industrial units and agricultural buildings often have pitched roofs. Churches, schools and older commercial premises may have slate, clay tile or concrete tile pitched roofs, sometimes with lead flashings and parapet walls.

Work on pitched commercial roofs involves the same fundamentals as domestic pitched roofing but usually at a much larger scale. Scaffold requirements, health and safety planning, access for materials and the sheer area of the roof all need careful organisation. We plan this before we start rather than working it out as we go.

Common problems on older pitched commercial roofs include corroded fixings in metal sheet systems, cracked or slipped fibre cement sheets, deteriorated ridge and hip mortar, and failed lead or zinc flashings around chimneys, rooflights and abutments.

Flat Roof Insulation and Energy Performance

If the existing roof is being stripped back to the deck, it makes sense to upgrade the insulation at the same time. Older commercial buildings often have inadequate or no roof insulation. Adding a rigid insulation board beneath the membrane can make a measurable difference to heating costs in a warehouse or office.

There are two main approaches. A warm roof puts the insulation above the structural deck and below the waterproofing membrane, keeping the deck at a stable temperature and reducing the risk of condensation. A cold roof insulates at ceiling level and relies on ventilation of the roof void above. Warm roof construction is now the preferred approach on new flat roof installations because it is more reliable in practice and meets current building regulation requirements more easily.

If your flat roof is being replaced rather than repaired, ask about the insulation specification. Adding thickness at the replacement stage costs relatively little compared to the saving over the life of the roof.

Roof Surveys and Condition Reports

Before quoting for any significant commercial roofing work, we carry out a proper survey. That means getting onto the roof, not just viewing it from the ground or from photographs. We check the membrane condition, the integrity of upstands and flashings, the falls and drainage outlets, the substrate and the deck where it is accessible.

Common problems we look for include:

• Ponding water from blocked or undersized outlets
• Blistering or splitting in felt membranes, usually caused by moisture trapped in the deck at the time of installation
• Delamination at laps and details
• Failed or missing upstand terminations at parapet walls
• Cracked or open joints in coping stones allowing water into the parapet cavity
• Cracked or deteriorated sealant around rooflights, pipes and conduits

A survey report gives you a clear picture of what needs doing now, what can wait and what to watch. That information helps you plan maintenance budgets rather than reacting to emergency leaks.

Roofing Contractors Covering Norwich and Nearby Areas

We work across Norwich and into the surrounding area, including Thorpe St Andrew and other neighbouring towns and villages. Commercial buildings in Thorpe and the city centre present different challenges, while out-of-town units may have large, open roof areas but poor access roads for scaffold deliveries.

Working around occupied buildings means planning work to minimise disruption to the people inside, coordinating access with building managers and making the roof watertight at the end of each working day where the job spans multiple days.

Rooflight and Skylight Work

Rooflights are one of the most common sources of leaks on commercial flat roofs. The problem is nearly always at the upstand, where the rooflight kerb meets the membrane, rather than the glazing unit itself. Over time, the sealant between the kerb and membrane dries, cracks and allows water in. In older installations, the upstand may be below the recommended 150mm minimum height, meaning any standing water reaches and potentially enters the joint.

Replacing a rooflight is a straightforward job if the deck around it is sound. If the deck has been saturated by a long-running leak, the repair becomes more involved because wet or delaminated decking will not hold a new fixing and will continue to cause problems under a new membrane if it is not addressed.

How Commercial Roofing Is Priced

Commercial roofing is priced by area and by system. As a general guide, torch-on felt replacement on a flat roof in Norwich typically runs from around £45 to £80 per square metre, depending on the number of layers specified, deck condition and access requirements. EPDM systems generally sit in a similar range, though costs vary with membrane thickness and how complex the detailing is. These figures cover the membrane system itself and do not include structural deck repairs, insulation upgrades or scaffolding, which are quoted separately once the scope is known.

Scaffold costs on commercial work can be significant, particularly on multi-storey buildings or where the roof boundary runs close to a public road. It is worth getting a full scope of work priced rather than comparing membrane costs alone, because a cheaper membrane quote that excludes scaffold or deck repairs can end up costing more overall.

Commercial flat roof replacement in Norwich typically costs between £45 and £80 per square metre for the membrane system, with additional costs for insulation, deck repairs and access scaffolding depending on the specific building.

Maintenance and Ongoing Care

A flat roof that is not maintained will not reach its potential service life. The single most important maintenance task is keeping drainage outlets clear. A blocked outlet on a large flat roof can leave hundreds of litres of standing water sitting on the membrane, creating pressure on laps and joints and accelerating deterioration. On a poorly designed roof with inadequate falls, even partial blockage can cause permanent ponding.

We recommend that commercial flat roofs are inspected at least once a year, ideally in autumn before the wet season and again after any period of heavy wind. Catching a small split or a loose flashing edge early is far cheaper than dealing with the water damage inside the building after a winter of leaks.

If your building has a maintenance schedule, roofing should be on it. If it does not have one, a condition survey is a sensible starting point.

What to Ask Any Commercial Roofing Contractor

Before committing to a commercial roofing project, it is worth asking any contractor the following:

• Will they get on the roof to survey it before quoting, or are they quoting from a description?
• What is included in the quote - does it cover deck repairs, insulation, drainage work and scaffold?
• What system are they specifying and why does it suit this building?
• What are the manufacturer's stated performance expectations for the materials they are using?
• How will the building be kept watertight if the job takes more than one day?

A contractor who can give clear, specific answers to these questions is worth more than one who quotes low and fills in the details later.

Get Your Commercial Roof Assessed

If your commercial roof in Norwich is leaking, showing signs of wear or simply has not been looked at in several years, call us to arrange a survey. We will get on the roof, tell you what we find and give you a straight assessment of what needs doing and roughly what it will cost before you commit to anything.