Haverhill Roofers covers commercial roofing in Fulbourn and the surrounding area, working on flat roofs, profiled metal sheet roofs, box gutters and rooflights for industrial, retail, office and agricultural premises.
Call any time. Calls are answered day and night and passed straight to our roofers.
Knowing what happens at each stage of a commercial roofing job helps you plan around the work, avoid surprises and ask the right questions of any contractor. This page takes you through the whole process, step by step, from the initial look at your roof to the point where we hand the site back to you.
The first visit is about gathering information, not selling you a job. A thorough survey of a commercial roof covers the membrane or sheet surface, all flashings, box gutters, outlets, downpipes, rooflights, penetrations and the upstand around anything that passes through the roof. It also includes checking the substrate - the deck, boards or purlins beneath the waterproof layer - because laying a new membrane on a compromised substrate is one of the most wasteful mistakes in commercial roofing.
On flat roofs we probe suspect areas to check whether insulation or decking has become wet and soft. On profiled metal roofs we check fixings, lap sealants and the condition of any liner sheets inside. We note the fall of the roof (the angle at which it drains) and whether the drainage system is sized correctly for the roof area.
After the survey you should receive a clear written breakdown of what is wrong, what the options are and why we are recommending a particular approach. If a contractor cannot explain the reasoning behind their recommendation, that is worth questioning.
Once the scope of work is agreed, the next step is planning access and logistics. Commercial roofs present different access challenges depending on the building type. A flat-roofed unit with a parapet is often accessible by scaffold tower or low-level podium. A large industrial shed with a profiled metal roof may need a mobile elevating work platform (MEWP) or scaffold over a working yard.
Access planning matters more than many clients realise. The wrong access method on a flat roof creates foot traffic damage to the membrane during the job itself. On a metal sheet roof, walking on old, corroded sheets without proper precautions causes panels to fail underfoot.
Materials delivery also needs planning. On a large replacement job, materials are typically delivered to the roof by crane or conveyor. If your site has restricted access - a town-centre location, a shared yard, or a building close to a road - this has to be factored in before the job starts.
On a flat roof replacement, the old membrane is stripped back to the substrate. This is the stage at which the true condition of the roof becomes clear. Insulation that looked intact from above is sometimes found to be wet through once the membrane is lifted. Deck boards that were solid underfoot turn out to be delaminated where water has sat on them for years. Any failed sections need to come out and be replaced before the new system goes down.
Good practice is to have a clear agreement before work starts about how additional substrate replacement will be priced if the condition is worse than expected. Day-rate or per-square-metre rates for extra substrate work should be confirmed in writing, not left to be negotiated in the middle of the job.
Stripped materials - old felt, insulation boards, debris - need to be removed to a skip. On a large commercial site this often means multiple skip loads, and the cost of disposal is sometimes left out of cheaper quotes. Check that waste removal is included before you compare figures.
Where deck boards or insulation have been removed, like-for-like or upgraded replacement material goes in before the membrane. On a flat roof with a poured concrete or screed deck this step may not apply, but on timber-framed decks or built-up insulation systems it is often the most important part of the job. The falls of the roof can also be corrected at this stage by tapering the insulation boards - a much better solution than bodging a blocked outlet.
For a torch-on felt system, a base layer is bonded to the deck and the top cap sheet is torched over it. The key quality indicators are full bonding with no air pockets, laps that are wide enough and fully sealed, and drip edges formed correctly at the perimeter so water sheds away from the fascia and into the gutters.
For an EPDM rubber membrane, the sheet is unrolled and bonded using cold-applied adhesive. On a quality job the sheet covers the whole roof with as few seams as possible. Seams are taped with a double-sided EPDM-compatible tape and covered with a seam tape. Every upstand, outlet collar and penetration gets a separate detail piece fully bonded and overlapping the main sheet.
For profiled metal sheet replacements, new sheets are fixed to the purlins with screw-fixed through-fixings or clips, depending on the system. The laps between sheets and around any rooflights or ridge details are sealed and finished before the sheets are fixed off permanently.
Flashings are the last layer of weatherproofing at every junction between the roof and a wall, parapet, pipe or vent. Lead flashings are cut, dressed and fixed with lead clips and mortar-pointed or mechanically fixed depending on the substrate. Box gutters are relined or replaced at this stage, with new outlets and overflow provision checked against the roof area they serve.
Rooflights are either refitted with new gaskets and seals or replaced with new units. A new dome or panel on an old kerb needs the kerb upstand checked for height - current standards require at least 150mm above the finished roof level to prevent standing water backing under the rooflight during a heavy downpour.
Before we leave site, we walk the roof and check every detail - outlets clear, laps fully sealed, no debris left on the membrane, all perimeter flashings tight, downpipes clear and flowing freely. On a metal sheet roof this includes checking every fixing is torqued correctly and every lap sealed.
The site is cleared and any hired access equipment is returned. If the job has disturbed any internal areas - ceiling tiles shifted by vibration, dust from cutting - that is dealt with as part of the clean-up, not left for your staff.
We carry out commercial roofing work in Fulbourn and the surrounding area. If you want to know exactly what a job on your building would involve, call us to arrange a site visit and a proper survey before any commitment is made.
No obligation · We'll call you to arrange a free visit
Call any time. Calls are answered day and night and passed straight to our roofers.
