Leakmaster LV-Z is a moisture-cure, single-component, hydrophilic water-swelling sealant engineered for demanding waterproofing applications where a continuous, gun-applied bead is required. Upon contact with water, it swells approximately 2 times in volume through controlled distilled water absorption and hydrophilic swelling mechanisms — delivering reliable, long-term joint sealing performance in construction joints, retrofit waterstop installations, and concrete containment structures. Unlike rigid sealants, Leakmaster LV-Z maintains its rubber-like elasticity throughout the swelling process, ensuring a flexible, watertight barrier that adapts to joint movement and hydrostatic pressure conditions.
Key Features
Leakmaster LV-Z is a moisture-cure, single-component water-swelling sealant built for professional waterproofing applications in concrete construction joints, retrofit waterstop systems, and below-grade structures. Designed for straightforward field installation, it dispenses cleanly through standard general-use caulking guns — making it a practical solution for both new construction and retrofit joint sealing projects where a continuous, consistent bead is critical.
What sets Leakmaster LV-Z apart from conventional putty-type sealants is its combination of hydrophilic expansion and lasting elasticity. Upon water contact, it swells approximately 2 times in volume, actively filling voids and gaps within the joint to form a tight, self-sealing waterproof barrier. Critically, this expansion does not come at the cost of flexibility — the material retains its rubber-like elasticity throughout, allowing it to accommodate joint movement and cyclic hydrostatic pressure without cracking or losing seal integrity.
Once fully cured, Leakmaster LV-Z delivers physical properties that significantly outperform traditional putty-type sealants, making it a superior long-term choice for water treatment facilities, containment structures, tunnels, and any application demanding reliable, durable joint waterproofing. The product presents as a gray, putty-like material that blends cleanly into concrete joint applications.
Technical Specifications
| Specification | Value |
|---|---|
| Product Type | One component type water-swelling sealant |
| Color | Gray |
| Appearance | Putty like |
| Extrudability | < 20 sec (In house test at 25°C) |
| Slump | < 10 mm (In house test for 1 hour test at 25°C) |
| Swelling Property | 85 to 200 vol.% (In house test after 2 days immersions at 25°C) |
| Shelf Life | 12 months after the production month and year shown on the cartridge |
| Storage | Store in a cool, dark and dry place below 90°F (32°C) |
| Use Temperature Range | 41°F (5°C) to 104°F (40°C) |
| Surface Condition | When the surface is wet, Leakmaster LV-Z is not suitable |
Frequently Asked Questions
Where is Leakmaster LV-Z commonly used? Leakmaster LV-Z is well-suited for a broad range of waterproofing applications in concrete construction. Primary uses include water sealing at vertical joints in cast in-situ concrete and precast concrete structures, as well as general waterproofing work in water treatment plants, containment structures, tunnels, and below-grade foundations. It can also function as an adhesive to the first site-formed concrete surface prior to construction joint (CJ) installation, particularly where the surface is rough — making it a versatile companion product to retrofit waterstop systems.
How does Leakmaster LV-Z create a watertight seal? Leakmaster LV-Z is a hydrophilic, water-swelling sealant that activates upon water contact, expanding approximately 2 times in volume through controlled distilled water absorption and swelling mechanisms. This volumetric expansion fills voids and irregularities within the joint, forming a continuous watertight barrier. Importantly, the material retains its rubber-like elasticity throughout this process, maintaining long-term seal integrity even under cyclic hydrostatic pressure and joint movement.
Can Leakmaster LV-Z be applied to wet surfaces? No. Leakmaster LV-Z is not suitable for application on wet surfaces. Proper surface preparation is essential to ensure full adhesion and effective waterproofing performance. Surfaces must be clean, sound, and dry prior to application.
What is the recommended application temperature range? Leakmaster LV-Z should be applied at ambient and surface temperatures between 41°F (5°C) and 104°F (40°C). Application outside of this range may compromise cure performance and long-term seal integrity.
What are the storage and shelf life requirements? Store Leakmaster LV-Z in a cool, dark, and dry location below 90°F (32°C). The product has a shelf life of 12 months from the production month and year printed on the cartridge. Proper storage is critical to maintaining the hydrophilic properties and moisture-cure performance of the sealant.
Are there concrete coverage requirements for cast in-situ joints? Yes. When used in site-formed concrete joints, a minimum of 100mm of concrete coverage must be maintained on both sides of the Leakmaster LV-Z placement. This ensures the sealant is properly encapsulated within the joint and can perform effectively against hydrostatic pressure.
What are the basic application steps for the cartridge? Application is straightforward using a standard caulking gun. Begin by breaking the moisture-proofing aluminum foil seal on top of the cartridge, then cut the nozzle at the appropriate position for the desired bead size. Load the cartridge into a general-use caulking gun and apply the sealant continuously without interruption to the area being sealed. A consistent, unbroken bead is essential for maintaining full waterproofing continuity along the joint.
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