Flat roofs in Oxford

How a flat roof replacement runs

1. Survey of the deck. We check the covering, the edges, the outlets and the deck underneath, and look at the ceiling below for staining.
2. Written quote. Your quote lists the covering, any new deck boards or timbers, the upstands against walls, the edge trims and the outlet.
3. Strip to the deck. The old covering comes off. Soft or rotten boards are replaced so the new roof sits on a firm, dry surface.
4. New covering. Our job photos show torch-on felt: a base layer bonded down, then a cap sheet laid with the gas torch so the layers fuse into one waterproof skin.
5. Edges, upstands and lanterns. The covering is dressed up walls and parapets, around roof lanterns and into the outlet, which is where most flat roofs leak.
6. Final check. The roof is cleared, the outlet is tested with water and the work is signed off with the guarantee in writing.

Signs your flat roof needs attention

• Water still sitting on the roof two days after rain
• Blisters, cracks or splits in the felt
• Damp or staining on the ceiling under the extension
• A spongy feel underfoot when the roof is inspected
• Leaks around a roof lantern or skylight
• Felt lifting where the roof meets the house wall

Flat roof options we work with

• Torch-on felt: A multi-layer felt system bonded with heat. Our torch-on felt case study shows it laid between two brick parapet walls.
• Felt with a mineral finish: A finished cap sheet in grey or green that protects the layers beneath from sunlight, as on the extension roof in our gallery.
• Single-ply membranes: A one-piece sheet over the deck, seen on some flat roofs with lanterns in our job photos. Ask at the survey which covering suits your roof.
• New deck and timbers: Where the boards or joists have rotted, they are replaced before any covering goes down. Our job library includes new joists and plywood on a garage roof.

How long it takes

A garage or small extension flat roof is a one to two day job in dry weather. Larger roofs, new decks and roofs with lanterns take longer. Torch-on work needs a dry deck, so rain can move the start date by a day or two.

What affects the price

• Roof area
• Whether the deck or joists need replacing
• Number of lanterns, skylights and outlets
• Upstands against walls and parapets
• Access for materials and old covering
• Edge trims and any new guttering

Read the flat roof cost guide for our repair and replacement ranges.

Aftercare

Keep leaves and moss out of the outlet and the gutter it drains into. Avoid walking on the roof, and keep ladders and garden furniture off it. If water sits on the surface after rain, send us a photo before it finds a way in.