Cambridge Roofers provides commercial roofing in Potton and the surrounding area, working on offices, warehouses, retail units and light industrial buildings from initial inspection through to a finished, cleaned-up job.
Call any time. Calls are answered day and night and passed straight to our roofers.
One of the most common sources of frustration for business owners is not knowing what to expect once a roofer is involved. What happens first? How long will the building be disrupted? How do you know the work has been done properly? This page walks through a commercial roofing project step by step, so you know what a well-run job looks like before you agree to anything.
A proper commercial roof assessment is not a two-minute glance from the car park. On a flat roof, the roofer needs to get onto the surface and check the membrane, upstands, outlets, rooflights and parapet copings. On a pitched roof, that means checking the covering, the ridge, any hips, the flashings at abutments, and the guttering and fascias at the eaves.
For multi-storey buildings or large roof areas, safe access needs to be arranged before the inspection - whether that is a MEWP, scaffolding, or existing roof access hatches. Any roofer who gives you a firm price without gaining proper access to the roof surface should be treated with caution.
At the end of the inspection you should receive a clear explanation of what has been found, not just a price. That means understanding which areas have failed, why they have failed, whether the deck or structure beneath is affected, and what the realistic options are. On commercial buildings, the deck beneath a failed flat roof membrane is often the hidden cost - if it has been wet for long enough, sections of it may need replacing before a new covering goes on.
Once the inspection is complete, you will typically have a choice between repair, partial replacement and full re-roof. The right answer depends on the age and overall condition of the roof, not just the area that is visibly failing.
On flat roofs, the main material options in commercial work are built-up felt, EPDM rubber membrane and single-ply systems. Felt is the lowest upfront cost. EPDM is applied in large sheets with fewer seams, which means fewer potential leak points over time. Single-ply membranes such as TPO are common on larger industrial or warehouse roofs. For pitched roofs, concrete or clay tiles, natural slate, and profiled metal sheeting are all used depending on the building type.
Leadwork at flashings, abutments, chimneys and around VELUX-style rooflights is a separate consideration. Lead is the most reliable material for these details, and the quality of the dressing and fixing determines how long it lasts. Ridge and hip pointing should be checked at the same time as any major roof work - mortar-bedded ridges that have dried out and cracked are a safety risk and a common leak source.
Before any work starts, access needs to be confirmed and any protection put in place. On most commercial buildings this means erecting scaffolding or positioning a MEWP. The access method affects the programme and the cost, so it should be agreed clearly before work begins.
Protection of the building's contents and the area below is important. If a roof is being stripped on a building that remains in use, the exposed area must be protected against rain at the end of each working day. This is usually done with temporary sheeting. A roofer who strips more than can be covered in a single day without having protection materials on site is taking a risk with your building.
Guttering, fascias and soffits should be assessed at this stage too. If they are being replaced as part of the job, the scaffold should be positioned to give access to the eaves. Replacing guttering after the scaffold has come down adds unnecessary cost.
On a re-roof, the existing covering comes off first. On a flat roof, this reveals the decking beneath. Concrete decks are usually sound but may have cracked or hollow areas. Timber decks are more likely to have areas of rot or delamination, particularly around outlets and upstands where water has been sitting. Any damaged decking must be cut out and replaced before the new membrane goes on - covering a soft deck is a false economy that will lead to premature failure of the new covering.
On a pitched roof, stripping the old tiles or slates exposes the battens and underlay. Battens are often the weak point - they rot from the underside where condensation collects, even when the tiles above look perfectly sound. Underlay on older roofs may be the original bitumen-soaked felt, which will have degraded and should be replaced. Modern underlay breathes and performs significantly better.
Flat roof membranes need to be applied to a clean, dry and stable deck. EPDM is adhesive-bonded in large sheets; any creases or voids in the bond create weak points. Upstands, outlets and all penetrations are detailed individually - this is the most skilled part of the job and where poor work shows up earliest. Outlet dressing in particular must allow the membrane to drain fully without water sitting at the edge of the detail.
On pitched roofs, new underlay goes on first, followed by battens at the correct gauge for the tile or slate being used. The covering is then laid from eaves to ridge. Ridge and hip tiles should be fixed mechanically rather than bedded in mortar wherever possible - dry-fix systems are more resistant to frost and wind movement and do not need re-pointing over time.
Leadwork is dressed once the covering is in place. Lead needs adequate movement allowance - it expands and contracts with temperature, and if it is dressed too tightly it will work loose within a few years. Correct code of lead for the application matters too: thicker lead for wide flashings, appropriate code for soakers and stepped flashings.
Guttering on a commercial building carries large water volumes and needs to be the correct profile for the roof area it serves. Fascia boards should be checked for rot before gutters are rehung - a soft fascia will not hold fixings and the gutter will pull away. UPVC commercial guttering is practical and low maintenance. Cast iron guttering, found on older buildings, lasts well but needs regular painting to prevent joint failure.
Soffits keep birds and pests out of the roof space as well as providing a finished appearance. Ventilated soffits allow air movement through the roof space, which reduces condensation risk - important on commercial buildings where internal activities can generate significant moisture.
Once the work is complete, the finished roof should be walked and checked before the scaffold or access equipment comes down. Outlets should be clear and draining. All upstand and flashing details should be inspected. Any excess adhesive, off-cuts or debris should be removed from the roof surface - debris blocks outlets and accelerates surface wear.
Ground-level clean-up matters too. Stripped tiles, old felt and packaging need to be cleared before the scaffold comes down. A commercial premises left with debris in the car park or around entrances reflects poorly on the roofer and causes practical problems for the business.
You should expect to be walked through what was done and shown any areas that were found to need additional attention during the job. If something unexpected came up - a section of rotten deck, a cracked purlin - you should already know about it because it should have been flagged and agreed before being addressed, not presented as a surprise on the final bill.
Cambridge Roofers works on commercial buildings in Potton and across the wider area, including Cambridge, Newmarket, Saffron Walden and St Ives. We handle everything a commercial roof needs - flat roofs, pitched roofs, repairs, full re-roofs, leadwork, chimneys, VELUX flashings, guttering, fascias and soffits.
If you have a roof that needs attention or you simply want to know what condition it is in, call us for a straightforward assessment. We will tell you clearly what we find, what needs doing, and what it will cost.
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Call any time. Calls are answered day and night and passed straight to our roofers.
