Metal roof leakage often starts from small and repeated weak points: cracks, screw holes, sheet overlaps, seams, and areas exposed to long-term rain and UV. Once water enters these points, it can travel along the roof panel or roof structure before appearing indoors, making the actual leakage source difficult to identify.
For metal roof repair projects that require an exposed waterproofing system, CKS recommends the Aquaseal 305 + Fabric Seal 201 solution. This system combines a ready-to-use elastomeric waterproof coating with a polyester reinforcement fabric to strengthen critical leakage points and form a seamless, flexible waterproofing layer.
The Aquaseal 305 + Fabric Seal 201 system is designed for local repair and renovation of common metal roof leakage points, including:
· Cracks on metal roof surfaces or existing coating layers.
· Leaking screw holes and fastener points.
· Leaking overlaps between metal roof sheets.
· Weak seams and joints exposed to wind-driven rain.
· Small repair areas that require a UV-resistant exposed waterproofing finish.
It is especially suitable for maintenance and repair scenarios where the roof surface needs a direct exposed waterproofing layer without an additional protective layer.
Creates the main seamless waterproofing layer; provides UV resistance, flexibility and weatherproofing for exposed roof repairs.
Reinforces cracks, screw holes, overlaps and seams; improves coating layer strength and helps extend system service life.
Aquaseal 305 is a ready-to-use, single-component elastomeric coating formulated with premium rubber and resin. It is designed for exposed waterproofing and repair areas where flexibility, UV resistance and weatherproofing are important.
· Wear-resistant and light trafficable for maintenance access.
· Excellent UV aging resistance for exposed roof applications.
· Seamless and elastic coating layer that adapts to minor substrate movement.
· Designed for 5+ years of exposed use under suitable application and service conditions.
· Suitable for waterproofing, repair and renovation on roofs, terraces, exterior walls and other structural surfaces.
Fabric Seal 201 is made from high-quality polyester raw materials. It is compatible with most waterproof coatings and is used as a reinforcement layer in waterproof coating systems.
· High and uniform strength in both warp and weft directions.
· Bonds tightly with coatings and helps create a smooth construction surface.
· Good flexibility, high strength, corrosion resistance, and resistance to acids and alkalis.
· Easily wetted and penetrated by waterproof coatings for convenient application.
· Widely used as a reinforcement layer in various waterproof coating systems.
Before application, identify the real leakage points and inspect cracks, screw holes, sheet overlaps and seams. The repair area should be clean, stable and free from loose particles, oil, dust and visible rust.
1. Substrate preparation: Clean the metal roof surface and sand off rust at the repair area. Remove dust and loose particles after sanding.
2. Reinforcement treatment: Apply one coat of Aquaseal 305 at cracks, screw holes and seams. While the coating is still wet, embed Fabric Seal 201 into the wet coating layer and make sure it is fully wetted and bonded.
3. Top coating: Apply one additional coat of Aquaseal 305 over the reinforced area to fully cover the fabric and form a continuous waterproofing layer.
For screw holes, overlaps and seams, make sure the coating extends beyond the leakage point to create sufficient sealing width. Allow the coating to dry according to site temperature, humidity and product guidance before allowing normal service conditions.
· Targeted repair: Focuses on the most common local weak points of metal roof leakage.
· Reinforced protection: Fabric Seal 201 improves strength at cracks, screw holes and seams.
· Exposed finish: Aquaseal 305 is suitable for exposed roof repair without a protective layer.
· Flexible waterproofing: The elastomeric coating helps accommodate minor movement of the roof surface.
· Simple application: Ready-to-use coating and easy-to-embed reinforcement fabric make the system suitable for repair and renovation work.
· Do not apply over loose rust, unstable old coating, standing water or contaminated surfaces.
· For severely corroded panels, large holes, structural movement or repeated widespread leakage, roof panel replacement or professional inspection may be required before coating repair.
· Pay special attention to roof drainage. Poor drainage can increase water pressure on seams and overlaps.
· Always follow the latest product datasheet, application instructions and local site safety requirements.
Q: Can Aquaseal 305 be exposed directly on a metal roof?
A: Yes. Aquaseal 305 is designed for exposed waterproofing applications and offers UV resistance, flexibility and weatherproofing. It can be used without a protective layer in suitable exposed roof repair conditions.
Q: Why should Fabric Seal 201 be used at cracks and screw holes?
A: Cracks, screw holes and seams are stress concentration points. Fabric Seal 201 reinforces these areas, improves coating layer strength and helps reduce the risk of future cracking or separation.
Q: Can this system repair leaking overlaps between metal sheets?
A: Yes. Apply Aquaseal 305 along the overlap, embed Fabric Seal 201 into the wet coating layer, then cover it with another coat of Aquaseal 305 to create a reinforced sealing strip.
Q: Is this solution suitable for full metal roof waterproofing?
A: It can be used for repair and renovation projects on metal roofs. For large-area application, the roof condition, rust level, drainage, movement and previous coating condition should be inspected before deciding the final system design.
Q: Do I need to remove rust before applying Aquaseal 305?
A: Yes. Rust, dust and loose particles should be removed before application. Sanding off rust helps improve bonding and reduce premature failure.
Q: What are the main steps for this repair system?
A: Clean the substrate and sand off rust, apply one coat of Aquaseal 305 and embed Fabric Seal 201 at cracks, screw holes and seams, then apply one more coat of Aquaseal 305.
Need to repair cracks, leaking screw holes or leaking overlaps on a metal roof? Contact CKS for roof leakage diagnosis, product recommendation and application guidance for the Aquaseal 305 + Fabric Seal 201 waterproofing system.
