Flat roof repairs & replacements in London.

Flat-roof repairs or replacement: start with the condition

A local defect and an ageing roof covering can need different work. Tell us where water is appearing, the history of repairs and how the roof is used. We discuss whether a local repair or a wider renewal is appropriate.

A rooflight, a doorway, a parapet edge and a drainage outlet each introduce details that need to work with the main covering. We consider these when setting out the proposed work.

Replacing a flat roof: agree what is being renewed

A new waterproof surface and a full roof rebuild are different scopes. Before choosing the work, establish which existing layers can remain, what needs removing and whether the deck or other concealed areas need further investigation. The quotation should explain the proposed build-up and connected details, including outlets, rooflights and edges.

Tell us about rooms below, roof access and any planned changes to how the roof is used. These affect the arrangements and specification. Our Barnet flat-roof renewal and the projects below show genuine Avent work; the appropriate scope still depends on your own roof.

Request a flat-roof replacement quotation ↗

Seamless liquid waterproofing

The Golders Green, Hampstead and Leyton projects show examples of Avent’s seamless liquid roof renewals at different scales. Photographs record the work and its setting, from a domestic terrace to a residential block.

Avent is an approved applicator for Tecnopol and MonoSeal systems. The product system proposed for your roof, the preparation and any applicable guarantee should be identified in the quotation; manufacturer approval does not mean the same product is used on every roof.

What we consider before quoting for a flat roof

The roof’s condition, details and access determine the proposed work. Include existing photographs and tell us about previous repairs, recurring leaks or standing water. If you need a detailed written condition assessment before deciding on work, ask about our separate paid survey service.

• The condition of the existing roof covering
• Wall, rooflight, doorway and edge junctions
• Outlets and drainage arrangements
• Use of the roof as a terrace or access area
• Access, occupied rooms and shared entrances

Balcony waterproofing above office space in Mayfair

Water ingress from this Mayfair balcony was affecting the office below. Avent renewed the balcony and added an anti-slip finish, adding a commercial example to our domestic terrace and residential-block work.

A terrace or balcony needs the waterproofing and intended use considered together. Tell us whether the area is walked on, where water is appearing below and what access is available. The proposed system and finish are agreed for the particular area.

Discuss a leaking balcony or flat roof ↗

See the Mayfair project photograph in detail, or explore our commercial roofing service for managed buildings and office properties.

What affects flat-roof repair and replacement costs?

Roof area is only part of the price. A local repair, a suitable overlay and replacement involving removal of existing layers include different work. Preparation, the condition beneath the covering, drainage details, rooflights, access and waste removal all affect the quotation.

Ask what is included and excluded, how concealed damage would be handled and which materials and applicable guarantee terms are proposed. We discuss the assessment needed before providing a free written quotation. Use our roofing quotation checklist to compare the scope behind the price.

Discuss your flat-roof repair or renewal ↗

Understand the leak before choosing the work.

Our flat-roof leak guide explains what to tell your roofer, why an indoor stain may be away from the entry point and what to ask before an overlay. For more on seamless waterproofing and our completed projects, see our liquid roofing service.