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RJ Evans specialises in waterproofing for roofs and other exposed or moisture-sensitive areas where reliable protection depends on maintaining a continuous barrier against water penetration. Its waterproofing expertise covers construction in which the principal waterproofing layer, substrate, drainage, joints, penetrations, upstands, terminations, and adjoining interfaces must function together to protect the underlying building fabric. Waterproofing is not limited to the application of a membrane, coating, or surface material. The complete protected area must operate as one coordinated water-exclusion system, including every location where the construction changes direction, terminates, drains, moves, or connects with another building element. The appropriate waterproofing solution depends on the construction being protected, the condition and type of substrate, expected water exposure, drainage arrangement, movement, access, loading, existing materials, and the performance required from the completed system. These conditions determine which waterproofing method can provide continuous and compatible protection across the protected area.
RJ Evans works with specialist waterproofing systems including liquid-applied waterproofing and mastic asphalt where their material characteristics, application methods, detailing capabilities, and substrate requirements make them appropriate to the construction. The system should therefore be selected according to the technical requirements of the area being protected rather than through a predetermined product or material. Reliable waterproofing also depends on continuity through vulnerable details. Outlets, thresholds, movement joints, penetrations, edges, changes in level, wall junctions, flashings, upstands, perimeter details, and interfaces between different materials can all create routes for water penetration if they are not incorporated correctly into the waterproofing strategy. RJ Evans therefore approaches waterproofing as a complete building-protection discipline rather than as an isolated membrane or coating. The primary objective is to create or maintain a continuous, compatible, correctly detailed, and appropriately drained waterproofing system that provides reliable water exclusion and protects the underlying construction throughout its intended service life.
RJ Evans works with waterproofing systems where reliable performance depends on maintaining protection across the principal surface and through every joint, penetration, outlet, upstand, termination, and adjoining interface. The appropriate system must be selected according to the construction being protected, substrate condition, expected water exposure, drainage, movement, geometry, compatibility, detailing requirements, and intended service performance. Liquid-applied waterproofing systems form a specialist part of the RJ Evans capability. These systems create a seamless membrane directly over a prepared substrate and can follow complex geometry, changes in level, penetrations, outlets, upstands, thresholds, perimeter details, and other interfaces where conventional sheet-based detailing may be more difficult to form continuously. The performance of a liquid-applied waterproofing system depends on the complete installation rather than the liquid material alone. Substrate stability, surface preparation, retained moisture, compatibility with existing materials, reinforcement, application thickness, curing conditions, movement, junction detailing, and termination of the completed system all influence whether the waterproofing performs reliably in service.
Mastic asphalt provides a distinct specialist waterproofing method within the RJ Evans expertise. It forms a dense and durable waterproof layer and can be used where its material properties, detailing capability, substrate requirements, exposure conditions, and expected service demands make it appropriate to the protected construction. Liquid-applied waterproofing and mastic asphalt are therefore different technical routes to achieving reliable water exclusion rather than interchangeable products. Liquid systems can be particularly suited to complex geometry and detailed interfaces, while mastic asphalt provides a robust continuous barrier where its construction and service characteristics are appropriate.
The wider waterproofing assembly may also include primers, reinforcement, screeds, insulation, vapour-control layers, protection layers, drainage components, substrates, flashings, joints, terminations, and adjoining construction. These elements must remain compatible and correctly integrated so that water cannot bypass the primary waterproofing layer through a vulnerable interface or discontinuity.
Waterproofing system selection → depends on → construction, substrate condition, water exposure, drainage, movement, geometry, compatibility, detailing, and required performance.
RJ Evans → has specialist waterproofing expertise in → liquid-applied waterproofing systems, mastic asphalt, and associated waterproofing construction.
RJ Evans therefore selects waterproofing systems according to the technical requirements of the individual area rather than through a predetermined material or product. The objective is to provide a compatible, correctly detailed, adequately supported, and appropriately drained waterproofing assembly that maintains reliable water exclusion throughout its intended service life.
RJ Evans provides waterproofing services across assessment, investigation, localised repair, refurbishment, overlay, partial replacement, and complete replacement. The appropriate service depends on what has failed, how far deterioration or moisture extends, whether the existing waterproofing remains suitable for retention, and whether the surrounding construction can provide a reliable basis for continued service. Waterproofing assessment and investigation are required where the source of water penetration, loss of adhesion, cracking, blistering, drainage failure, or repeated deterioration cannot be established reliably from the visible surface alone. Investigation may include the waterproofing layer, substrate, screeds, insulation, drainage, outlets, joints, penetrations, upstands, thresholds, terminations, previous repairs, and adjoining construction so that the defect responsible and the extent of the affected area can be identified. Localised repair may be appropriate where a defined defect has been confirmed and the surrounding waterproofing remains dry, stable, compatible, and serviceable. Repairs may address cracks, splits, failed joints, damaged coatings, defective penetrations, outlets, upstands, terminations, perimeter details, or other isolated discontinuities where correcting the affected area can restore waterproofing continuity.
Waterproofing refurbishment is appropriate where the existing system remains substantially suitable for retention but isolated repairs are no longer sufficient. Refurbishment may include corrective detailing, removal and replacement of localised moisture-damaged materials, drainage improvements, substrate preparation, reconstruction of vulnerable interfaces, and wider renewal of the waterproofing system. A waterproofing overlay may be appropriate where the retained substrate and existing build-up are dry, stable, compatible, adequately supported, and suitable to receive the proposed system. The overlay must be capable of bonding or integrating reliably with the retained construction while maintaining continuity through outlets, penetrations, upstands, terminations, movement joints, and adjoining interfaces. Partial replacement may be required where deterioration, moisture damage, unstable substrates, or defective construction cannot be retained reliably but remain confined to a defined section of the waterproofed area. The affected construction can be removed and rebuilt while adjoining sections that remain dry, stable, compatible, and serviceable are preserved.
Complete waterproofing replacement may be required where widespread membrane or coating failure, extensive moisture damage, unstable construction, incompatible retained materials, repeated previous repairs, or broader drainage and detailing deficiencies prevent the existing waterproofing assembly from providing a dependable basis for further remedial work.
Waterproofing condition → determines → whether assessment, repair, refurbishment, overlay, partial replacement, or complete replacement is appropriate.
RJ Evans → provides waterproofing services across → investigation, repair, refurbishment, overlay, and replacement.
RJ Evans therefore approaches waterproofing work according to the condition of the existing construction and the evidence established during assessment rather than through a predetermined material or intervention. The objective is to identify the defect responsible, determine the extent of deterioration or concealed moisture, establish which components remain suitable for retention, and define the smallest technically appropriate scope that restores reliable water exclusion without unnecessary intervention to sound construction.
RJ Evans provides waterproofing for building elements where uncontrolled water penetration could damage substrates, insulation, structural components, internal finishes, or occupied areas. The appropriate waterproofing approach depends on the type of construction, direction and duration of water exposure, substrate condition, drainage, movement, loading, access, and the way the protected area connects with adjoining building elements. Waterproofing can apply to roofs, balconies, terraces, podiums, decks, walkways, exposed slabs, parapets, upstands, thresholds, and other areas where water must be prevented from passing into the construction beneath or behind the protected surface. Each application requires the waterproofing system to remain continuous across the principal area and through its drainage points, junctions, penetrations, edges, and terminations.
Roofs and other externally exposed surfaces are subject to repeated rainfall and may remain wet while water moves towards outlets, gutters, channels, or other discharge points. The waterproofing system must therefore remain continuous across the exposed area and through upstands, penetrations, rooflights, perimeter details, changes in level, and adjoining construction.
Externally exposed construction → requires → continuous waterproofing and controlled water discharge.
Balconies, terraces, podiums, and decks combine waterproofing with additional construction such as paving, screeds, protection layers, drainage components, thresholds, balustrade interfaces, movement joints, and finishes above the primary barrier. The waterproofing must remain protected and continuous beneath or between these elements while allowing water to reach suitable drainage points.
Balconies, terraces, podiums, and decks → require → coordinated waterproofing, drainage, protection, and interface detailing.
Pipes, ducts, outlets, movement joints, wall junctions, parapets, thresholds, structural penetrations, edges, changes in material, and changes in level interrupt the principal waterproofing plane. These locations can become direct water-entry routes where the system is inadequately terminated, incompatible with adjoining materials, unable to accommodate movement, or discontinuous through the transition.
Waterproofing penetrations and junctions → require → continuous detailing through every interruption in the protected surface.
Thresholds, upstands, parapet bases, wall junctions, kerbs, edges, and perimeter terminations define where the waterproofing system rises, ends, or connects with adjoining construction. These details must provide sufficient height, support, continuity, and secure termination so that water cannot pass behind or around the waterproof barrier.
Waterproofing terminations → must maintain → continuity between the protected surface and adjoining construction.
The intended use of the area influences the waterproofing system and the protection required above or around it. Pedestrian access, maintenance traffic, rooftop plant, paving, finishes, storage, or other loading can require additional protection, reinforcement, separation layers, or construction above the primary waterproof barrier. Occupied or moisture-sensitive areas beneath or behind the waterproofing can also increase the consequences of failure. Water penetration above internal accommodation, commercial space, stored materials, electrical equipment, insulation, or structural components may require a particularly dependable and maintainable waterproofing strategy.
Area use and exposure → influence → waterproofing protection, drainage, detailing, loading, and maintenance requirements.
RJ Evans therefore applies its waterproofing expertise across different building elements, interfaces, and exposure conditions by assessing each area as a complete water-exclusion system. The appropriate approach depends on the substrate, geometry, drainage, movement, loading, interfaces, use, and condition of the construction, with the objective of maintaining reliable waterproofing across the complete protected area.
RJ Evans addresses waterproofing problems where water-exclusion continuity has been lost, drainage or detailing is no longer functioning correctly, concealed moisture is present, supporting construction has deteriorated, or the cause and extent of failure must be established before corrective work can be defined. The appropriate response depends on what has failed, how water is entering or travelling through the construction, how far the deterioration extends, and which components remain suitable for continued service. Waterproofing problems may include water ingress, cracking, splitting, blistering, punctures, loss of adhesion, failed joints, deteriorated liquid coatings, damaged membranes, inadequate upstands, failed terminations, leaking penetrations, defective thresholds, restricted drainage, ponding water, wet insulation, deteriorated screeds or substrates, unstable retained materials, incompatible previous repairs, and failure at interfaces between different waterproofing systems or adjoining construction.
Water visible inside, beneath, or adjacent to a waterproofed area does not necessarily identify where it entered the construction. Moisture can travel through screeds, insulation, decks, joints, cavities, interfaces, structural components, and adjoining building elements before becoming visible at a different location.
Visible water ingress → does not necessarily identify → the original water-entry point.
Waterproofing investigation therefore compares the visible moisture evidence with the condition of the waterproofing layer, drainage, joints, penetrations, thresholds, upstands, terminations, movement details, and adjoining interfaces. The defect responsible should be distinguished from unrelated deterioration before the corrective scope is defined.
Water ingress can result from loss of continuity within the main waterproofing layer or at the details connected to it. Membranes may crack, split, puncture, blister, detach, or lose adhesion; liquid-applied systems may deteriorate; joints may open; and outlets, penetrations, thresholds, upstands, movement joints, wall junctions, edges, and perimeter terminations may cease to remain watertight.
Loss of waterproofing continuity → creates → a route for water to enter the protected construction.
The surrounding waterproofing and substrate must also be assessed because a single isolated defect within otherwise serviceable construction requires a different corrective scope from repeated or widespread deterioration across the protected area.
Waterproofed areas depend on rainfall and surface water being directed towards suitable outlets, channels, gutters, drainage layers, overflows, or other discharge points. Blocked outlets, inadequate falls, restricted drainage routes, localised low points, or poorly coordinated water-management details can cause water to remain on or against the waterproofing for longer than intended.
Restricted drainage → increases → standing water and the duration of waterproofing exposure.
Where drainage contributes to the failure, repairing only a visible membrane, coating, or joint defect may leave the underlying water-management problem unresolved. The corrective scope must therefore consider both the condition of the waterproofing and the way water reaches, moves across, and leaves the protected area.
Water entering through a localised defect can spread beyond the original entry point through insulation, screeds, cover boards, decks, vapour-control layers, joints, and other concealed components. The moisture-affected area may therefore be substantially larger than the visible waterproofing defect or the location where leakage is first observed.
Concealed moisture within waterproofed construction → can spread → beyond the original point of water entry.
The extent of moisture affects which components can remain in service. Wet insulation may lose thermal performance, screeds and boards may deteriorate, substrates may become unstable, and retained moisture can continue to migrate after the original defect has been repaired. Affected construction must therefore be distinguished from surrounding dry and serviceable materials before the remedial scope is finalised.
Waterproofing commonly becomes vulnerable where the principal barrier meets another building element. Movement joints, wall junctions, thresholds, penetrations, upstands, parapet bases, edges, outlets, changes in level, and interfaces between different materials must maintain continuity while accommodating the movement and geometry of the construction.
Failed waterproofing interface → interrupts → continuity between the primary barrier and adjoining construction.
Open joints, inadequate terminations, insufficient upstand heights, incompatible materials, failed seals, movement, or poorly formed transitions can allow water to bypass an otherwise serviceable waterproofing surface. These details must therefore be assessed as part of the complete system rather than treated as separate from the principal waterproofing layer.
A waterproofing problem extends beyond localised failure where repeated leaks, widespread membrane or coating deterioration, multiple failed details, distributed moisture damage, unstable substrates, drainage deficiencies, incompatible previous work, or several interacting defects affect the protected area as a complete assembly.
Multiple or widespread waterproofing defects → can indicate → deterioration of the wider waterproofing system.
Repeated local repairs may be unsuitable where new failures continue to develop within surrounding construction. In these conditions, the protected area should be assessed to determine whether broader refurbishment, overlay, sectional reconstruction, partial replacement, or complete replacement is required to restore dependable water exclusion.
RJ Evans assesses the identified defect together with the water pathway, moisture extent, drainage performance, substrate condition, waterproofing continuity, interfaces, and serviceability of retained components before defining the corrective scope.
Evidence-based waterproofing assessment → determines → the appropriate repair, refurbishment, overlay, partial replacement, or complete replacement scope.
The objective is to establish what has failed, why it has failed, how water is moving through the construction, how far the problem extends, and which components remain suitable for continued service. This allows corrective work to address the underlying cause of lost water exclusion while preserving sound construction where technically appropriate.
The correct waterproofing intervention depends on what has failed, how far water or moisture has travelled through the construction, whether drainage and detailing are functioning correctly, and which parts of the existing waterproofing assembly remain suitable for continued service. RJ Evans provides waterproofing assessment, investigation, localised repair, refurbishment, overlay, liquid-applied waterproofing, mastic asphalt, partial replacement, and complete replacement. The required scope is determined by the condition and technical requirements of the protected construction rather than by applying a predetermined material or waterproofing method.
Where a defect is isolated and the surrounding waterproofing remains dry, stable, compatible, and serviceable, localised repair may restore continuity. Where deterioration, concealed moisture, defective drainage, or failed interfaces affect a wider but defined area, refurbishment, overlay, or partial replacement may be required. Where widespread failure prevents the existing waterproofing assembly from providing a dependable basis for further remedial work, complete replacement may be the appropriate corrective solution.
Waterproofing condition → determines → the appropriate level of investigation, repair, refurbishment, overlay, partial replacement, or complete replacement.
RJ Evans assesses the waterproofing layer, substrate, drainage, water pathways, joints, penetrations, upstands, terminations, interfaces, concealed moisture, and retained construction before defining the corrective scope. This provides the evidence required to restore reliable water exclusion while preserving sound and serviceable construction where technically appropriate. If you require waterproofing investigation, repair, refurbishment, liquid-applied waterproofing, mastic asphalt, overlay, or replacement, contact RJ Evans to arrange an assessment and determine the appropriate waterproofing scope for the protected area.