Thetford Roofers carries out commercial roofing work for business premises and industrial units in Brandon and the surrounding area, from first survey through to completed job.
Business owners and premises managers rarely see the detail of what goes into a properly executed commercial roofing job. This page walks through the full process - from the first visit to the final clean-up - so you know what to expect and what to ask for. We cover Brandon and the towns and villages nearby, including Thetford, Attleborough, Watton, Mundford, Methwold and Mildenhall.
A commercial roof survey is not a five-minute walk around the car park. On a flat roof, the surveyor needs to get onto the surface and inspect it methodically - checking the membrane condition across the whole field of the roof, not just the areas that are visibly failing. On a pitched commercial roof, that means examining sheet fixings, lap conditions, ridge and verge details, and the condition of any rooflights or penetrations.
The gutters and downpipes are checked at the same time. A roof that is in serviceable condition but is shedding water against the building because the gutter has corroded or collapsed will cause as much damage as a failed membrane. On larger commercial premises, the outlet positions on flat roofs are checked against the roof area they drain to confirm adequate capacity.
Inside the building, visible signs of water ingress - staining, damp patches, rust marks on steelwork - are noted. These give useful information about where water is entering, even if the exact entry point on the roof surface is not immediately obvious. Water travels: the stain you see inside may be well away from where the membrane is breached.
The deck condition is assessed where possible. On a flat roof, any areas of soft decking underfoot indicate that moisture has reached the board below the membrane. This changes the scope and cost of the job significantly, because softened decking must be replaced before a new membrane goes on top of it. A survey that does not check for soft decking is not a complete survey.
After the survey, the scope of work is set out clearly: what is being stripped, what is being replaced or repaired, what the membrane or sheet system will be, and what the drainage and flashing details will involve. On a refurbishment job, the specification should state whether the existing membrane is being stripped back to the deck or whether an overlay is proposed, and why.
Pricing a commercial roof honestly requires knowing the deck condition. If an area of decking is suspected but cannot be confirmed until stripping starts, that should be flagged as a contingency item with a clear unit rate - for example, a rate per square metre of deck board replacement - so there are no unexpected conversations about cost once work is underway.
Typical costs for commercial flat roof work in the UK run from around £40 to £65 per square metre for a torch-on felt system, and from £60 to £90 per square metre for an EPDM rubber membrane installation. Re-sheeting a pitched commercial roof in profiled metal or fibre cement sheets typically runs from £25 to £60 per square metre depending on the material and the complexity of the detailing. These figures are for the roofing work itself and assume the deck or purlin structure is in sound condition.
Commercial roofing almost always requires scaffold or a mobile elevated work platform. The access method depends on the building height, the roof area and what is around the building - car parks, service yards and loading bays all affect how scaffold is positioned and whether it can be left in place for the duration of the job or needs to be moved in stages.
For occupied premises, the access setup should be planned so that your staff and any visitors to the site can move safely around the building while work is in progress. Scaffold netting reduces the risk of falling debris. On premises where the roof is above an active workspace, an internal protection layer - heavy-duty sheeting over equipment or stock - is sensible as a precaution while the old membrane or sheeting is lifted. These are practical matters to discuss before work starts, not assumptions to make.
Materials are delivered and stored on site in a way that does not block emergency exits or loading access. On a flat roof job, the new membrane rolls or insulation boards may be craned or winched to roof level rather than hand-balled up a ladder, particularly on larger areas. The method affects the programme and should be stated in the plan.
On a flat roof refurbishment, stripping the old membrane back to the deck is the point at which the true condition of the job becomes clear. Areas of softened or damaged decking that were suspected during the survey are confirmed and measured at this stage. Any decking that is wet, delaminated or structurally unsound is cut out and replaced before the new waterproofing goes on. Laying a new membrane over a failing deck is one of the most common causes of premature flat roof failure, and it is avoidable.
On a pitched roof re-sheet, old sheets are removed carefully to avoid damage to the purlin structure below. The purlins are inspected for corrosion (on steel frames) or rot and insect damage (on timber). Damaged purlins need to be addressed before new sheets are fixed; a new sheet fixed to a failing purlin will not hold correctly in wind.
Waste is managed as the job progresses. Old felt, insulation boards and sheet offcuts are bagged and taken off site. On a large commercial job, a skip is usually positioned in advance. Removing debris from the roof surface at the end of each working day is standard practice - loose material left on a flat roof deck overnight is a wind risk as well as a slip hazard for the people working on it the following morning.
The main membrane or sheeting goes on once the deck or purlin structure is confirmed as sound. On a flat roof, this means the membrane is installed to the specified system - whether torch-on felt or cold-bonded EPDM rubber - with the manufacturer's specified overlap widths and bonding method at all seams.
The detailing work - upstands, flashings, outlets and any penetrations through the roof - takes longer per metre than the main field and is where the quality of the job is really determined. An upstand that is too short (less than 150mm above the finished roof surface is generally inadequate) or a flashing that is mechanically fixed but not sealed will fail before the main membrane. Outlets must be recessed into the membrane so that water drains into them rather than pooling around them.
On a pitched roof re-sheet, sheet laps are laid to the correct overlap for the pitch of the roof and the profile of the sheet, then fixed with the correct type and number of fixings for the wind load the building is exposed to. Ridge and eaves details are finished before the scaffold or access platform is struck.
Commercial gutter repairs and replacement are carried out alongside the roofing work rather than as an afterthought. Replacing a flat roof and leaving a corroded or undersized gutter system in place is a common false economy. On a large industrial unit, cast steel or aluminium box gutters run the full length of the building and carry significant volumes of water. These are cleaned, checked for corrosion and resealed or replaced as part of the overall scope.
Flat roof outlets are cleared and tested before the job is signed off. On a new membrane installation, the outlet collars are integrated into the membrane and sealed, and water flow to each outlet is confirmed as part of the final inspection.
Before the scaffold comes down, the roof is walked and inspected in full. Every flashing, outlet, upstand and edge detail is checked. Any area of the membrane that does not look right - a wrinkle that might indicate inadequate bonding, or an edge that has not adhered fully - is addressed before access is lost. This is the point at which a thorough job separates itself from a rushed one.
Once the inspection is complete, the scaffold or access equipment is struck and removed. The site is cleared of all materials, off-cuts and debris. Access to the premises is fully restored. The customer is shown the completed work - either by walking the roof together or, where roof access is not practical for a non-roofer, with photographs of all the critical details.
If you have a commercial roof in or near Brandon that needs attention, call Thetford Roofers to arrange a survey. We will assess the roof properly, explain what we find and give you a clear price before any work begins.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
