Flat roofs cover a surprising amount of Newcastle housing: kitchen offshoots on terraces, back extensions, dormers, garages, bay windows and porches. They work hard. Water sits on them longer than on a pitched roof, and every joint, edge and outlet is a possible leak.
Newcastle Roofs repairs and replaces flat roofs in felt, EPDM rubber, GRP fibreglass and single-ply membranes. Many flat roof leaks show up well away from where the water actually gets in, so we spend time finding the real entry point before suggesting a fix. Some roofs need only a new upstand or outlet. Others have reached the end of their life, and we will say so and explain the replacement options in plain terms.
Where flat roofs usually fail
The middle of a flat roof is rarely the problem. Leaks usually start at the details:
- Upstands and abutments, where the roof turns up a wall and is protected by a flashing. Movement, failed lead or mortar can open a gap.
- Outlets and gutters, which block with leaves and moss, causing water to back up over the edge or around the outlet.
- Laps and seams in felt or membrane that have opened through age or poor bonding.
- Ponding, where a sagging deck or poor falls leave standing water that accelerates wear and finds any weakness.
Current guidance for flat roofs expects a finished fall of at least 1 in 80 so water drains away. Older roofs were often laid much flatter, and a sagging joist can create a dip that never drains properly.
Choosing a system for repair or replacement
Where a roof needs replacing, the choice of covering matters:
- Built-up felt – modern torch-on or cold-applied reinforced bitumen systems are far tougher than the old three-layer felt many houses still have. A good choice for most domestic roofs.
- EPDM rubber – a single sheet with few or no joints on a small roof, laid cold with adhesive. Flexible and tolerant of temperature changes.
- GRP fibreglass – rigid, seamless and neat, suited to roofs with simple shapes and a stable deck.
- Single-ply TPO or PVC – welded seams and a lightweight sheet, often used on larger or more complex roofs.
No single system suits every roof. We recommend one based on the size and shape of the roof, how much foot traffic it gets, what it adjoins and how the deck is built.
Warm roofs, cold roofs and condensation
Many older flat roofs were built as cold roofs, with insulation between the joists and a ventilated gap above. Without enough ventilation, warm moist air from the room condenses under the deck, which rots the boards and can drip back through the ceiling, looking like a leak. On Tyneside's damp winter days this is common above bathrooms and kitchens.
A warm roof puts the insulation on top of the deck with a vapour control layer beneath, keeping the timber warm and dry. When a flat roof is replaced, Building Regulations normally expect the insulation to be upgraded to current standards if that is technically feasible, and converting to a warm roof is often the neatest way to do it. Raising the roof level can affect doors and windows above, so we check heights first.
Rear offshoots and shared roofs in Newcastle
On many Victorian and Edwardian terraces, the rear offshoot roof drains into a valley or gutter shared with the next house, and the roof may butt against your neighbour's wall. Lead or mortar flashings along that boundary wall are a frequent source of leaks. In Tyneside flats, the offshoot roof may serve the downstairs flat while the upstairs flat looks out over it, so responsibility should be checked in the deeds. Access is often through a back yard, so we plan ladders, materials and waste around narrow lanes. If the offshoot sits under a bathroom window, we also make sure any new upstand finishes safely below the sill.
