STP Shalimar Dam-it
Single-component hydraulic plugging mortar that sets in two to three minutes — formed by hand and forced into live leaks in concrete and masonry, even against running water.
What is it?
A ready-to-use grey cementitious powder from STP that needs only water to produce a rapid-setting plugging mortar for stopping active water ingress.
Where is it used?
Basements, manholes, concrete pipes and bell joints, floor-wall junctions, tanks and tunnels — plus quick anchoring of bolts and handrails.
Why use it?
It stiffens and sets within 2-3 minutes of mixing and expands slightly as it hardens, wedging itself into the cavity for a watertight repair.
How is it applied?
Mixed to a stiff putty at a 0.18 water-powder ratio, shaped into a plug by hand, forced into the leak as it warms, and held under pressure for about five minutes.
About STP Shalimar Dam-it
Shalimar Dam-it is STP’s first-response product for water that refuses to wait. When a basement raft weeps at a construction joint, a manhole wall streams during monsoon, or a tank has to go back into service the same day, conventional repair mortars are useless — they wash out before they can set. Dam-it is engineered for exactly this moment: a single-component hydraulic mortar that reaches initial set in two to three minutes and keeps hardening in direct contact with water, so a trained applicator can physically overpower a live leak with a handful of material.
For contractors, the practical appeal is its simplicity. There is no liquid component, no bonding agent and no curing regime — just clean water at 180 ml per kilogram, a quick mix, and speed of hand. Strength development is equally businesslike: around 170 kg/cm² within a day, climbing to 320 kg/cm² at 28 days, which means the plugged zone can accept protective coatings or screeds almost immediately. Space Arc Engineering stocks Dam-it in 1 kg and 25 kg packs for site teams across Delhi NCR and ships pan-India, and our applicators use it routinely as the arrest step in larger basement remediation jobs.
The technical insight
Dam-it works because its binder hydrates far faster than ordinary cement, and that hydration is strongly exothermic. The heat is not a side effect — it is the applicator’s signal. The TDS method is to hold the mixed plug in a gloved hand until it suddenly begins to warm, typically 2-3 minutes from the start of mixing; at that instant the mortar is entering initial set and must be forced into the leak. Two things then defeat the water. First, the mix is dimensionally expansive as it sets, so instead of shrinking away from the cavity walls like normal mortar, it wedges outward and locks in mechanically against hydrostatic pressure. Second, because the reaction consumes mix water internally, flowing water cannot dilute the plug once it is compacted and held — five minutes of firm hand or trowel pressure is usually enough for it to resist the stream on its own.
Where it is used
- Plugging active leaks in basement rafts, retaining walls and diaphragm wall joints
- Stopping seepage at floor-wall junctions and forming watertight coves
- Manhole, chamber and wet-well repairs for water and sewage networks
- Concrete pipe and bell-joint repairs on gravity and pressure lines
- Sealing pipe penetrations and sleeve openings with running water
- Emergency leak-stopping in water tanks, cisterns, sumps and tunnels
- Rapid anchoring of foundation bolts, handrails and fixtures
- Arresting ingress before waterproof coating or injection systems are applied
Key advantages
- Initial set in 2-3 minutes — fast enough to beat actively flowing water
- Slightly expansive on setting, so the plug locks into the cavity instead of shrinking loose
- Single component; only clean water is needed, with no bonding agent or special curing
- Hardens in direct water contact — the substrate does not need to be dried first
- Reaches roughly 170 kg/cm² in 24 hours, so coatings and screeds can follow the same day
- Hand-workable in small batches, ideal for confined pits, shafts and chambers
- Doubles as a rapid-set anchoring mortar for bolts and railings
- Small 1 kg packs let maintenance teams keep an emergency stock without waste
Limitations & considerations
- It arrests the leak but is not a standalone waterproofing system — a follow-up coating or membrane is needed for a permanent solution
- Working time is only 2-3 minutes, so material must be mixed in small hand-size batches; anything not placed in time is wasted
- Application is specified between 16°C and 32°C; in hot Indian site conditions the set accelerates further and ice-cold mixing water may be needed
- As a rigid cementitious repair it is unsuitable for moving cracks or dynamic joints, which will re-open the repair
- It does not relieve the hydrostatic pressure behind the wall — relief holes are often required and must themselves be plugged in sequence
- Do not re-temper the mix or trowel extra water onto the surface while finishing; both weaken the plug
Selection & best practice
Preparation decides success. Cut cracks open to at least 15 mm x 15 mm, remove unsound concrete, oil and paint, roughen with a wire brush or scabbler, and vacuum or pressure-wash the zone. Where water is running hard, relieve pressure first — drill a relief hole or chisel the crack at its lowest point, seal everything else, and plug the relief point last. Mix small quantities at 0.18 water to powder (about 180 ml per kg) with a drill and jiffy mixer for around a minute, keep the batch in your gloved hand, and the moment it warms, ram it into the opening. Work top-down on cracks and hold each plug under firm hand or trowel pressure for a full five minutes — longer if the water is very cold. In hot weather, mix with ice water to buy working time. Finish flush without adding surface water, then protect the area with a cementitious waterproof coating such as ShaliCem EWP.
Specifications
| Form / appearance | Cementitious grey powder, single component |
| Setting behaviour | Warms and reaches initial set in 2-3 minutes from start of mixing |
| Compressive strength, 1 day | 170 kg/cm² |
| Compressive strength, 7 days | 280 kg/cm² |
| Compressive strength, 28 days | 320 kg/cm² |
| Mixing ratio | 0.18 water : powder by weight (approx. 180 ml per 1 kg) |
| Application temperature | 16°C to 32°C |
| Pack sizes | 1 kg and 25 kg |
| Shelf life / storage | 12 months in original sealed packs; store cool, dry and under shed |
Industry use cases
High-Rise Basements, Delhi NCR
With shallow water tables across Noida, Gurugram and East Delhi, raft slabs and diaphragm walls routinely leak at tie-rod holes and construction joints. Dam-it arrests each ingress point so injection or coating crews can work on a dry face.
Water & Sewage Utilities
Jal boards and O&M contractors use it for manhole walls, benching, wet wells and concrete pipe bell joints — repairs that must hold against live flow because shutting the line down is rarely an option.
Metro, Tunnels & Hydro Structures
Seepage points in tunnel linings, shafts, galleries and dam appurtenant works can be plugged during short maintenance windows, with the mortar gaining structural strength within hours.
Industrial Plants & ETPs
Leaking pits, trenches, sumps and effluent tanks are sealed in minutes rather than days, keeping process downtime to a single shift and letting protective linings follow immediately.
Repair & Maintenance Contractors
One bag covers two trades: emergency leak-stopping and rapid anchor-setting of bolts, handrails and machine fixings, which makes it a permanent item in facility maintenance stores.
Frequently asked questions
Will Dam-it really stop water that is actively flowing out of a crack?
How much water do I add?
Is this a complete waterproofing solution on its own?
Can I apply it underwater or inside a tank that still holds water?
How do I manage the short setting time in summer?
What pack sizes are available and how should I store them?
How we position STP Shalimar Dam-it
Within the STP family, Dam-it is the emergency-response product: it stops the water so a permanent system can go in. The manufacturer itself recommends over-coating the repair with ShaliCem EWP, STP’s cementitious waterproof coating, and for larger basement or tank refurbishments we typically pair the two before any membrane or protective work. Where a project is standardised on Fosroc specifications, Renderoc Plug performs the same live-leak arresting role, and persistent cracks under hydrostatic pressure are better closed permanently with a PU injection system after Dam-it has stemmed the flow. Space Arc supplies and applies all of these across Delhi NCR and pan-India.
Fosroc Renderoc Plug — Specifiers on Fosroc-standardised projects, or those wanting single-brand warranty continuity with other Renderoc repair mortars, can use Renderoc Plug for the same rapid live-leak arresting duty.
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