The short answer
A flat roof over a shop is usually repaired from the rear, by ladder, hoist or a platform, so the shopfront can stay open. Leaks start at seams, upturns, outlets or old patches, not across the whole surface. Who owns the roof, whether flats sit above, and how the covering was laid all affect the repair, so the survey comes first, then one written price.
Flat roofs over shops and parades: where leaks start, what flats above change, and how a rear-access repair works.
Where a shop flat roof usually leaks
Water finds the weakest detail, and on a flat roof that is seldom the open surface. Look first at the places where the membrane climbs a wall, the upstand, where the covering or its flashing has lifted or split. Next come the outlets and rainwater pipes, the seams between sheets or lengths of felt, and any old patches laid on top of earlier patches. A roof that holds standing water long after rain deserves a look too, since a flat roof should be laid to a fall. BS 6229:2025 keeps a minimum 1:80 finished fall for general roof areas.
Shop roofs have extra features. Signage fixings, extract ducts from a kitchen, air conditioning units and aerials all pierce or sit on the covering, and each penetration is a place for a leak. Parapet walls trap water if their copings fail. Rear extensions often meet the main building with a lead or felt flashing that moves as the structures settle.
A repair that finds the true cause lasts. Spreading black coating over a wet roof without tracing the entry point rarely does. Our page on commercial roof drainage problems covers the outlet side.
Flats above and who owns the roof
Many parades have flats above the shops, and that changes the repair. The flat roof over the shop may be a rear extension belonging to the commercial lease, while the main pitched roof above belongs to the freeholder or is shared. Find out who owns and who repairs each part before ordering work, because a lease may place the cost on the freeholder, on the tenant or on all occupiers through a service charge. Our page on who pays for commercial roof repairs explains how those splits work.
Residents above need notice. Work may bring noise, access through shared areas and restrictions on working hours. A leak into a flat can become a dispute between neighbours, so keep a record of when the leak began and what was done. Take care with ladders and hoists near flat windows and balconies.
If the roof is a walkway or fire escape route for the flats, mark it clearly and keep it open. The survey should record which parts of the roof people use, because that decides the type of covering and the protection it needs.
Rear access, deliveries and keeping the shop trading
Shops rarely have a convenient front for roofers. Access is usually from the rear: a service yard, an alley behind the parade or a side passage shared with neighbours. A good plan begins with a visit to look at it. How wide is the route? Is there a loading bay we can use, and when are deliveries made? Can materials be lifted by hoist or telehandler, or must everything be carried?
Scaffold that sits on a public footway involves the highway authority, and councils differ on who applies, so ask the scaffolder early. Standing it on private land needs no licence. Rear access often avoids the street altogether, which keeps the shopfront clear and customers walking in.
Exclusion zones protect the staff and the public. Our answer on roof repairs while a business is open covers phasing and quiet hours. Ladders and platforms need safe footing and edge protection at the parapet or eaves, as our answer on roof edge protection requirements explains.
Repair or replace, and what typical guides say it costs
A local repair suits a roof that is sound apart from one or two faults. Replacement suits a roof where the covering has failed across the surface, the insulation is wet or repairs keep returning. EPDM, a synthetic rubber membrane, has a published expected service life of 20 to 30 years (GreenSpec); torch-on felt lasts less and GRP, a glass-reinforced plastic coating, more (Less, March 2026). Our pages on the EPDM commercial roof and single-ply roofing membrane compare the choices.
As a national guide, Checkatrade's September 2026 figures give £80 to £100 per m² for EPDM and £50 to £80 per m² for felt, which are yardsticks only. The price for your roof depends on its area, the access, the insulation and what the survey finds, and shop roofs can need extra work around ducts and parapets. Ask each firm to confirm whether VAT and scaffold sit inside its total, and what happens to the rooflights, vents and flashings that surround the repair area.
Our price arrives as one written total once the roof has been surveyed. Begin by telling us the address, who owns the roof and where the water shows inside. Our commercial roofing page lists the wider work.
More on this in Commercial Roofing in Crawley & Gatwick
Two shop roof questions
Can a leak over a shop be fixed quickly?
A leaking roof is first made safe, perhaps with a temporary seal over the entry point while the cause is traced. The lasting repair follows once the survey shows where water gets in and what sits beneath the covering. A quick patch alone can hide a wider fault, so the cause is always checked.
Do I need the freeholder's permission to repair?
It depends on your lease. Some leases leave the roof to the landlord, some put it on the tenant and some require consent before works. Read the repair clauses first, and tell the freeholder or managing agent about a leak in writing. A roofing report with pictures helps whichever way the lease falls.