Thetford Roofers handles commercial roofing projects across Attleborough and the surrounding area, from flat roof replacements to full re-sheeting of industrial and agricultural buildings.
If you have not arranged commercial roofing work before, it helps to know what to expect at each stage. The process on a well-run job is methodical, and understanding it means you can plan around the disruption, ask the right questions and spot if something is being skipped.
A commercial roofing survey is not a five-minute walk around the perimeter. For a flat roof, the surveyor needs to get onto the roof to assess the membrane condition, check the deck for softness or rot (on a timber deck), inspect all upstands, kerbs and penetrations, and look at how water drains from the roof. A thermal survey can identify areas of wet insulation beneath a membrane that look perfectly sound from the surface - wet insulation conducts heat out of the building and causes the membrane above it to behave differently from the rest of the roof, accelerating deterioration.
For a sheeted pitched roof, the survey should include the fixings, the condition of the sheets at laps and ridges, the state of any roof lights, the gutter system, and the supporting structure beneath. On older agricultural or industrial buildings, purlins and roof rails sometimes show corrosion or deformation that affects what re-roofing options are available.
The outcome of the survey should be a clear description of what needs doing and why. A price that is given without a survey being carried out first should be treated with caution - it either contains a large contingency to cover unknowns, or it does not.
Before any work starts, there should be a written specification that sets out the scope of the job. This is not just a price - it should describe the materials being used (system type, manufacturer, thickness or gauge), how penetrations and upstands are to be treated, what happens to the existing material (strip and dispose, or over-sheet), and what access method is being used. A specification protects you as the building owner and gives the roofer a clear reference for what was agreed.
If there is any possibility that existing sheets contain asbestos - common on farm buildings and older industrial units - this needs to be resolved before the specification is finalised. An asbestos survey may be required before licensed removal can be arranged. This is a separate cost and a separate contractor, but it is a legal requirement and cannot be skipped.
Commercial roofing work requires a safe system of access. On most jobs this means scaffolding, a mobile elevated work platform (MEWP), or a combination of both depending on the building height and profile. For re-sheeting a low-pitched agricultural building, a MEWP and working from the purlins with safety harness attachment points is often the most practical approach. For work on a flat roof above a busy retail or commercial premises, scaffolding with edge protection is the standard.
Access equipment has a cost that should be visible in the quotation. If a price seems very low for the size of job, ask specifically how access is being provided. Inadequate access arrangements are one of the most common sources of accidents on commercial roofing sites.
Where the existing roof is being stripped rather than over-sheeted, this stage involves removing the old material section by section and disposing of it correctly. On a flat roof, stripping back to the deck reveals its true condition - areas of rot or delamination that were not obvious from above will be found at this point. A contingency allowance in the budget for deck repairs is sensible on any flat roof job where the deck is of unknown condition or age.
On a sheeted roof, stripping involves removing the existing sheets, ridge cappings and flashings, and any failed gutterwork, before the new sheets go on. Where over-sheeting is the agreed approach, the existing sheets stay in place and the new profile is fixed through them into the purlins. Over-sheeting is quicker and avoids disposal costs, but only works where the purlins are sound and the extra weight is within the structural capacity of the frame.
Flat roof installation starts with any deck repairs, then insulation boards where required, then the membrane. On an EPDM rubber system, large panels are laid out and bonded to the deck with contact adhesive. Seams between panels are bonded with seam tape and roller-pressed. Upstands, kerbs and penetrations are dressed in matching EPDM and sealed with bonding adhesive. The work is largely cold-applied, which removes the fire risk associated with torch-on systems and makes it practical on buildings that are still in use below.
On a sheeted roof, new sheets are fixed from the eaves up to the ridge, overlapping as specified by the sheet manufacturer. Fixings go through the crown of each rib into the purlin below, with neoprene washers to seal each penetration. Ridge cappings, eaves fillers and flashings at gable ends and any abutments are fitted last. Roof lights are installed in the correct bays before the adjacent sheets are fixed off.
Gutters are replaced or repaired as part of the same operation - fitting new gutters after the sheets are on is significantly more difficult than doing it as part of the re-roofing sequence.
A proper handover involves a walkover inspection with the building owner or their representative before the access equipment is removed. This is the opportunity to check that all flashings are correctly dressed, that outlets and gutters are clear and flowing correctly, and that the roof lights specified are in place. Any snags should be identified and resolved at this stage, not after the scaffolding has come down.
Clean-up on a commercial roofing job means removing all waste material, metal swarf from drilling operations (which will rust and stain if left), packaging and any equipment from the site. A skip on site for the duration is the cleanest approach on a larger job. The area around the building should be left in the same condition it was found.
Not every visit results in a full replacement. Gutter cleaning and repair, moss removal and treatment, isolated sheet repairs and roof light replacements are all standalone services. On commercial buildings, these smaller jobs are often deferred and then forgotten until they cause a larger problem. A programme of annual gutter clearing on a commercial building is straightforward to arrange and far less costly than dealing with the water damage that blocked gutters cause.
Thetford Roofers works on commercial and agricultural buildings in Attleborough and the wider area, including Thetford, Watton and nearby towns and villages. Call us to arrange a survey and discuss what your building needs.
No obligation · We usually respond within 2 hours
Storm damage, active leak, damaged ridge - we aim to be on-site within 24 hours.
