Flat roofs · Repairs & renewals
Flat roofing in London
From an extension roof to a block of flats, we assess the complete flat roof and recommend a practical route for repair or replacement.
Look beyond the surface.
A flat roof needs more than a waterproof covering. Its condition is also influenced by drainage, the supporting deck, insulation and the details at edges, walls and penetrations. We consider the roof as a system when discussing the work.
We work with liquid waterproofing, GRP and felt roofing, with the approach chosen around the roof’s condition and requirements. Tell us about leaks, standing water, soft areas or previous overlays when you enquire.
Repair, overlay or full renewal?
A sound roof with a local defect may be repairable. An overlay depends on the suitability and condition of what remains beneath it. Where the retained construction is deteriorated or unsuitable, stripping the roof may provide a more appropriate route. The recommendation follows assessment rather than a surface appearance alone.
The details that shape the specification
We discuss the waterproofing alongside drainage and the condition of the existing construction. Where the scope calls for investigation or specialist design input, this needs to be identified before the work is agreed.
- Deck condition and areas of deterioration
- Falls, outlets and rainwater drainage
- Roof edges, upstands and parapets
- Insulation and ventilation considerations
- Pipe penetrations, rooflights and access hatches
Flat roofing for blocks and managed buildings
For freeholders and managing agents, a clear schedule of work helps explain the scope and compare quotations. We can discuss condition reporting, access, occupied areas and how the roof work will be organised.
Discuss your project
What we can help with
- Flat roof repairs and replacements
- Liquid waterproofing, GRP and felt
- Extensions, blocks and commercial roofs
- Drainage and edge details
- Condition surveys and work schedules
Related services
- Roof replacements
- Roof repairs
- Leadwork & chimneys
- Emergency roofing

Flat roof waterproofing
Approved expertise. A system chosen for your roof.
Avent is a MonoSeal approved applicator and a Tecnopol approved contractor for Desmopol flat roofing systems. We will explain the proposed system, preparation and finishing details as part of your quotation.
The right choice depends on the roof beneath the covering, drainage, access and the way the space is used. Any system warranty, eligibility and maintenance requirements are confirmed for the specified work.
Your questions
A little clarity, before you decide.
If you have a specific concern about your roof, tell us when you enquire.
Is standing water always a sign the roof must be replaced?
Not by itself. Its extent, duration and the condition and requirements of the roof system matter. Persistent ponding should be assessed alongside the falls, outlets and covering, particularly where there are leaks or deterioration.
Can a new covering go over the existing roof?
An overlay may be possible where the retained construction is suitable. Its condition and compatibility need assessment; it should not be assumed from a visual inspection of the top surface alone.
Do you provide guarantees?
Guarantee options depend on the selected system, specification and installation requirements. Ask us to set out the applicable manufacturer and workmanship arrangements in the quotation, including their scope and exclusions.
Related roofing services
The right support for your roof.
01 / Roofing
Roof replacements
Slate, tile and complete roof renewals, planned around your property.
03 / Roofing
Commercial roofing
Roofing for blocks, freeholders and commercial properties, with the scope and access planned together.
Start with a conversation
Tell us what needs attention.
Tell us what needs attention, where the property is and how we can reach you. We’ll discuss the right next step.
Tell us about your roof
Your postcode and a few details are all we need to start.
Felt, GRP and EPDM rubber roofs
Different flat roof coverings have different preparation, jointing and detailing requirements. If your roof has felt, GRP fibreglass or EPDM rubber, tell us when you enquire. We will discuss the condition and confirm the repair or replacement system we can provide. A manufacturer name or material choice is not, on its own, a guarantee of suitability.
