A flat roof should be assessed as a complete build-up, from the deck and insulation to the waterproofing and rainwater outlets. EPDM, GRP and reinforced-bitumen systems offer different approaches. The appropriate choice depends on the roof's condition, shape, use and specification, with particular attention to edges, upstands and penetrations.
Discuss your flat roofHow water reaches the outlets.
Deck, insulation and waterproofing.
Edges, rooflights and adjoining walls.
The right scope begins with the condition of your property.
Confirm the access, existing condition and any connected work during the assessment. Photographs can help start the conversation.
Rain on the finished flat roof, with the adjoining pitched roof, dormer and roof window beyond.
Explore the project photographsThe existing surface is only part of the assessment. The roof's condition, supporting deck, junctions and drainage need consideration before a repair, overlay or replacement is proposed. An overlay is not a universal answer, and any retained layers must be suitable for the chosen system and the condition of the roof.
The waterproofing layer works with the rest of the roof. Insulation, vapour control and supporting layers should be coordinated within a project-specific specification. A useful quotation identifies the proposed system and its components, rather than describing the work simply as a new rubber, fibreglass or felt roof without further detail.
Outlets, roof edges, wall abutments and penetrations need compatible details within the selected system. Their condition and arrangement should be considered alongside the main roof surface. Where a proposal changes the existing drainage or connections, those alterations should be included clearly in the scope and explained before the work begins.
The roof's intended use matters when choosing the specification. Occasional maintenance access and a roof terrace are different requirements. The handover should explain suitable access, routine checks and any maintenance obligations, together with the actual terms of any applicable product or workmanship cover for the particular installation and build-up.
In a warm roof, insulation sits above the structural deck and below the waterproofing. A cold roof places insulation below the deck and relies on a suitably designed ventilated space above it. Changing between these arrangements needs a coordinated design for moisture control, insulation and ventilation. Adding a new surface alone does not establish that the layers beneath it are suitable.
Tapered insulation can help create drainage falls, but the increased roof height may affect door thresholds, wall upstands and perimeter details. Moving or adding an outlet also depends on where the water can discharge. A renewal proposal should show how the finished surface drains and explain any consequences for adjoining windows, walls or rooflights, rather than treating the waterproof covering as an isolated layer.
Agree what is included, what remains uncertain and how any additional work will be authorised.
The suitable system depends on the roof's shape, condition, use and complete specification. EPDM, GRP and reinforced-bitumen systems have different installation approaches and detailing requirements. Compare the proposed build-up, product, installation method and applicable terms rather than relying on a simple material ranking.
Sometimes, but the existing roof must first be assessed for suitability. The retained substrate and layers need to be compatible with the chosen system and in an appropriate condition. An overlay should be justified for the particular roof, rather than assumed to be suitable because it avoids removal.
No. A manufacturer's service-life statement and a guarantee are different things. Actual cover can depend on the specified build-up, installer status, installation requirements and maintenance. The quotation and handover should identify the cover that applies to the particular project and explain its scope and conditions.
A carefully planned sample can reveal the existing roof layers and help assess their condition, including insulation and trapped moisture. Whether sampling is appropriate depends on the roof and proposed work. The survey scope should explain the method, permissions and how the opening will be made watertight.
Not by itself. A low area may relate to the existing falls, the supporting deck or its deflection. The cause needs assessment before deciding whether alterations to the structure, insulation layout, drainage or a combination of these are appropriate.
Whether you have noticed a problem or are planning a larger change, begin with a few details about the property and the work you have in mind.
Tell us what is happening and how urgently you need help. An online enquiry does not confirm attendance or an emergency response.
