Make the overlay decision after establishing the cause
A roof overlay adds a new waterproofing system over retained construction. Before approving one on a Cyprus property with standing water, establish why the water collects and whether the layers underneath can reasonably remain. A new surface may address a membrane defect while leaving the depression, restricted outlet or wet insulation that complicates the repair.
The useful survey question is therefore more precise than whether the roof leaks: can the proposed assembly provide a compatible waterproofing system, a workable drainage route and maintainable details without retaining unsuitable material? An answer should identify the evidence behind each condition rather than reduce the entire roof to a single pass or fail.
Start by giving the investigator the intended outcome, available construction records and any previous repair information. Waterproofed.cy’s waterproofing assessment is a suitable starting point for defining that investigation; specialist testing and opening-up should be separately identified in the agreed scope.
Record the puddle as a changing condition
A photograph taken immediately after rain shows where water was visible at that moment. It does not establish how long the water remained or whether an outlet was temporarily obstructed. Record the observation time, approximate rainfall timing, subsequent weather and whether somebody cleared or swept the roof before the visit. These details make later comparisons meaningful.
Use a roof plan to locate pond boundaries, outlets, overflows, penetrations and changes in surface level. Where safe and accessible, record representative water depths and reference levels rather than estimating the depression from a photograph. The surveyor should also distinguish water retained behind debris from water sitting below the effective outlet level.
Do not arrange deliberate flooding merely to recreate a puddle. A measured level survey and observations after natural rain may answer the drainage question without adding water loads. If controlled water testing is proposed, it needs its own purpose, suitability assessment, containment arrangements and approval.
Separate surface geometry from concealed moisture
The ponding map and the retained-layer condition map answer different questions. One describes drainage at the exposed surface; the other investigates what may be wet or unsuitable below it. A visibly dry area is not automatically a sound overlay substrate, just as a puddle does not establish the full extent of concealed moisture.
Sika describes recording wet and dry zones to inform partial or full removal, with roof falls and dimensional assessments among its possible survey activities. This supports commissioning a combined investigation rather than selecting an overlay from surface appearance alone. It does not mean any particular instrument proves the condition of every layer. See Sika’s on-site condition reporting.
Ask the investigator how anomalous readings will be checked and where access limitations remain. If representative openings are necessary, agree their locations, permissions and reinstatement before work begins. The report should distinguish observed construction from assumptions extrapolated across areas that were not opened.
Check compatibility at the lowest details
The lowest point often exposes a weakness in an otherwise attractive overlay proposal. Raising the surrounding surface can leave an existing outlet recessed awkwardly, reduce available upstand height or make a threshold more vulnerable. A coating thickness alone rarely explains the finished geometry: local repairs, reinforcement, primers and any falls correction also belong in the proposed section.
Identify the existing membrane where possible, including earlier coatings and patch materials. Then obtain the proposed system manufacturer’s preparation and compatibility requirements for that actual substrate. Sika’s roofing concepts document expressly calls for a project-specific survey and assessment when selecting refurbishment solutions for polymeric roofs. Its discussion is system guidance, not approval of an unidentified roof. See Sika’s roofing refurbishment guidance.
Where adhesion trials are proposed, specify their locations and interpretation in advance. A successful trial on one clean patch should not silently approve contaminated patches, moving joints or retained wet layers elsewhere.
Write a brief with clear inclusions and exclusions
A useful brief includes the accessible survey area, drainage observations, level measurements, membrane identification effort, condition mapping and the evidence required to recommend retention or removal. Name the deliverables: an annotated plan, photographs, findings by location and a repair recommendation with unresolved points clearly marked. This makes competing proposals easier to assess.
State exclusions just as precisely. An initial visit might exclude structural calculations, concealed pipe investigation, destructive openings, laboratory analysis and removal of equipment. Those exclusions should trigger an additional instruction when needed; they should not disappear into a broad claim that the roof has been fully investigated.
Assign decisions to people. The investigator recommends further investigation, the membrane supplier confirms its system requirements, and a structural professional addresses suspected loading or movement issues. The owner or authorised building manager approves scope changes and expenditure. Waterproofed.cy’s overview of waterproofing work provides service context, while the project brief determines what this particular instruction includes.
Compare three realistic repair routes
Consider a hypothetical apartment roof where water remains beside an outlet after rain. Measurements suggest that a raised patch interrupts the route to the drain. Investigation also identifies one locally unsuitable area beneath the existing covering. These are two findings requiring coordinated action; neither justifies assuming the entire roof needs replacement or that an uninterrupted overlay is acceptable.
The first possible route is a compatible local repair and drainage correction where the surrounding construction is suitable for retention. The second is an overlay incorporating approved removal and rebuilding of defined areas, with outlet and upstand alterations drawn explicitly. The third is more extensive removal where the investigation cannot establish a dependable retained base or workable junctions.
Ask each tenderer to price against the same recommended route and identified uncertainties. A proposal that omits the outlet alteration is not equivalent to one that includes it, even if both describe themselves as complete waterproofing. No route should be selected solely because its surface material tolerates occasional standing water.
Approve the repair with evidence and hold points
Before authorising installation, require a drawing or marked photograph explaining the revised drainage path and each affected junction. The specification should identify retained layers, removal boundaries, preparation, compatible materials and the inspection needed before those details become concealed. If opening-up reveals a different construction, pause the affected work and obtain a revised proposal.
Agree what completion evidence can demonstrate. Photographs of exposed preparation, outlet connections and completed reinforcement can support workmanship records. A suitable test may investigate watertightness, while repeat level measurements or subsequent rain observations address drainage. These are separate outcomes, and neither provides an unlimited prediction of future performance.
Request an assessment of the ponding area before accepting an overlay quotation. Include photographs after rain, approximate standing-water duration and any existing roof specification. Ask for a recommendation that explains whether an overlay is feasible, what must change first and who must approve each outstanding issue.
Frequently asked questions
Does standing water automatically mean the existing roof must be removed?
No. The decision depends on drainage geometry, retained-layer condition, junction heights and the proposed system’s requirements. Removal may be local or extensive, but its extent needs evidence.
Can an adhesion test establish whether insulation underneath is dry?
No. An adhesion trial assesses a particular bonded interface under its test conditions. Concealed moisture requires an appropriate investigation of the roof build-up.
Should the survey include a flood test?
Only where a separately assessed test answers a defined question and is suitable for the roof. Mapping ponding does not itself require deliberate flooding.
Who approves extra removal discovered during preparation?
The authorised owner or manager approves the commercial change after receiving the investigator’s recommendation and any necessary technical input. Agree this process before installation.
Sources
Sources checked 2026-10-15.
- Sika: On-site Condition Reporting
- Sika Technology and Concepts for Roofing
- Waterproofed.cy assessment and service information
Request an assessment of the ponding and waterproofing detail