For stopping active water leaks under pressure in basements, subways, and concrete water tanks, Lamposilex provides an ultra-fast setting plug that halts water flow within minutes. This chloride-free hydraulic binder mixes with water to form a thixotropic paste that hangs on vertical surfaces without formwork, curing rapidly to block cracks, holes, and joints against hydrostatic pressure.
Lamposilex relies on a rapid hydration mechanism. When mixed with water, it transitions from a workable, plastic consistency to a rigid, waterproof plug in approximately one and a half minutes at +20°C. Once set, it exhibits high compressive and flexural strength within 30 minutes, ensuring the plug resists the shear forces of pressurized water. Because it contains no chlorides, it will not contribute to the corrosion of steel reinforcement. Additionally, it is certified to AS/NZS 4020:2018, making it safe for sealing joints and cracks in contact with potable water.
For sealing active water leaks, enlarge the crack or hole to a minimum of 2 cm wide and 2 cm deep, keeping the inner cavity wider than the exterior opening (dovetail profile) to mechanically lock the cured plug in place. Remove all loose material from the cavity.
For rigid wall-to-floor joints, remove degraded concrete and clear dust with compressed air. Thoroughly wet the substrate so it is saturated but free of standing surface water before application.
Mix 1 kg of powder with 280 g of water (or 2.5 parts powder to 1 part water by volume) using a trowel until smooth. Mold the mix manually into the shape of a cork, wait a few seconds until the curing process begins, then force the plug into the hole. Hold under constant pressure for 2 to 3 minutes until fully set. For rigid joints, work the mix into the cavity immediately after mixing, and keep the surface damp for the first 15 to 20 minutes.
Yes, Lamposilex is AS/NZS 4020:2018 certified for potable water contact. It can be used for sealing cracks and joints in drinking water infrastructure without leaching harmful substances.
It sets rapidly, typically within 90 seconds at 20°C. This fast cure allows for immediate arrest of active water ingress, but requires mixing small batches for quick application.
Yes, stopping running water is its primary function. Mould the mixed material into a "cork" shape, wait for slight stiffening, then firmly force it into the leak and hold pressure for 2-3 minutes until fully set.
The minimum application temperature is +5°C. For cooler conditions, using water at approximately +20°C and storing materials in a heated area can help ensure proper setting.
| Application | Key benefit | Primary trades |
|---|---|---|
| Stopping active water leaks under pressure | Ultra-fast 90-second set controls water ingress immediately and prevents further damage. | Waterproofers, Remedial Contractors |
| Sealing rigid wall-slab junctions | Forms a dense, waterproof plug that minimises shrinkage and creates a lasting seal. | Builders, Waterproofers |
| Waterproof sealing of cracks and holes | Hand-mouldable, thixotropic paste allows for effective application on vertical surfaces and secure mechanical keying. | Builders, Remedial Contractors |
| Potable water infrastructure repairs | AS/NZS 4020:2018 certification ensures suitability for contact with drinking water systems. | Plumbers, Asset Maintenance |
Dovetail cavities (~20 mm × 20 mm), remove loose material and dust, wet to SSD.
Cut with the wider section inside to create mechanical key and resist pressure blow-out.
Thoroughly pre-wet; remove free water with compressed air or sponge to achieve SSD.
Mix 100:28 by weight (2.5:1 by volume) to a smooth, lump-free paste.
Add powder to water while stirring with trowel until uniform. Prepare small batches only.
Keep material out of sun; use very cold water to maintain working time.
Hand-mould a plug and force into the cavity; hold 2–3 minutes until set, then trim excess.
Apply from the top down when multiple leak points exist; maintain firm pressure during initial set.
Pack the mix tight with a trowel/float; keep surface damp for the first 15–20 minutes.
Wear safety glasses, suitable gloves, and protective clothing. Avoid skin and eye contact. Minimise dust exposure during handling.
Ensure adequate ventilation during mixing and placement, especially in confined spaces such as basements or tanks.
Store dry and indoors, avoiding direct sunlight. Shelf life is 12 months in original, unopened packaging. Dispose of contents and containers in accordance with local regulations.
Proper substrate preparation is critical for Mapei Lamposilex to achieve its hydraulic lock and prevent callbacks.
Surface prep: Chase out cracks or holes to a minimum width and depth of 20mm. Cut a dovetail shape (wider at the back) to create a mechanical key. Remove all loose debris and unsound material. If water is not actively running, saturate the area thoroughly with water before application.
Primer: Not required. Lamposilex functions via mechanical locking and hydraulic setting properties against a damp substrate.
| Property | Value |
|---|---|
| Base Chemistry | Hydraulic binder (high-strength cements with special admixtures) |
| Colour | Grey |
| Density | 1100 kg/m³ |
| Consistency | Fine powder, Plastic-thixotropic paste when mixed |
| pH Value | 12.8 |
| Compressive Strength | 46 MPa |
| Flexural Strength | 9 MPa |
| Pot Life | Approx. 1 minute |
| Initial Cure | Approx. 1.5 minutes |
| Application Temperature | +5°C |
| Mix Ratio | 2.5 parts Lamposilex : 1 part water (by weight) |
| Coverage Rate | 1.8 kg fills 1 dm³ cavity |
| Clean Up | Mechanical removal |
| Standards | AS/NZS 4020:2018 |
| Packaging | 1 box with 4 x 5 kg bags |
| Shelf Life | 12 months |
Here are some common examples on where Mapei Lamposilex (Waterplug) used by our customers.
