About STP ShaliProtek PuR L

STP ShaliProtek PuR L is the brush-friendly member of STP’s ShaliProtek polyurea family. Where pure spray polyureas gel in seconds and demand heated, high-pressure plural-component equipment, PuR L is formulated with a deliberately long working time. That single design choice changes who can use it: an ordinary applicator team can mix, decant and hand-apply it with brush or roller, reaching parapets, curves, upstands and congested detailing that a spray gun struggles to cover evenly. The cured film still behaves like a polyurea membrane, seamless, elastomeric and forgiving of substrate movement, but the product meets the reality of Indian sites where machine spray is often impractical.

For engineers and contractors, that makes it a versatile waterproofing and protective coat for concrete and metal. It bonds to properly prepared substrates, bridges fine shrinkage cracks through its high elongation, and forms a continuous barrier with no laps or seams to fail. It suits roofs, basements, water-retaining structures and precast elements, and it is equally at home as a protective topcoat where a resilient, chemically robust film is wanted over structural concrete. Space Arc Engineering supplies ShaliProtek PuR L as an authorised STP distributor and applicator across Delhi NCR and pan-India, so you can pair the material with on-ground application support rather than sourcing it blind.

The technical insight

Polyurea membranes owe their toughness to the fast reaction between an isocyanate component and an amine-terminated resin, which builds a densely cross-linked, highly elastic polymer. In a pure spray polyurea that reaction is almost instantaneous, which is why those systems need metered, heated, high-pressure guns. ShaliProtek PuR L keeps the elastomeric polyurea backbone but chemically slows the cure so the mixed material stays workable long enough to spread by hand. The result is a film with high elongation, over 300% in extension, and useful tensile strength that lets the membrane stretch across moving cracks and joints and recover instead of tearing. Because it goes down wet-on-wet as a liquid, it self-terminates around penetrations, drains and upstands to give a genuinely monolithic barrier. One honest trade-off worth flagging: like most polyurethane and polyurea coatings, prolonged UV exposure can shift its colour over time. That change is cosmetic; it does not degrade the membrane’s physical or waterproofing performance, but for permanently exposed surfaces a UV-stable topcoat keeps the finish looking consistent.

Where it is used

• Waterproofing of RCC roofs, terraces and podium slabs
• Basement raft, retaining and shear-wall waterproofing (positive side)
• Internal lining of water-retaining tanks and reservoirs
• Coating of precast concrete panels and segments before or after erection
• Membrane detailing over curved surfaces, domes, upstands and vertical faces
• Protective, elastomeric coating over structural concrete exposed to moisture
• Waterproofing and protection of metal substrates where a flexible film is needed
• Refurbishment overlays on sound existing waterproofing where a seamless hand-applied coat is required

Key advantages

• Long working time lets crews brush and roller apply it without heated plural-component spray equipment
• Seamless, monolithic membrane with no laps or joints that can become failure points
• High elongation (over 300%) bridges fine cracks and tolerates substrate movement
• Elastomeric polyurea film delivers durable, resilient waterproofing and surface protection
• Applies by brush, roller or airless spray, so one product covers both broad areas and tight detailing
• Bonds well to correctly prepared concrete and metal substrates
• Two-coat build gives controllable, uniform film thickness on complex geometry
• Backed by Space Arc’s authorised distribution and on-site application support across India

Limitations & considerations

• Two-component product: it must be accurately batched and thoroughly mixed on site, so it needs a disciplined applicator
• Prolonged UV exposure can cause colour change; a UV-stable topcoat is advised on permanently exposed surfaces
• Performance depends heavily on substrate preparation, cleanliness, priming and dryness
• Should not be applied when rain is imminent on exposed areas, and it needs a suitable cure window
• Clean-up and thinning require the correct STP thinner, not general-purpose solvents
• As a hand-applied coating it does not deliver the second-scale set or throughput of machine-sprayed pure polyurea on very large decks

Selection & best practice

Specifications

Industry use cases

How we position STP ShaliProtek PuR L

Within the STP ShaliProtek family, PuR L is the hand-applied option; its siblings ShaliProtek PuR 100 (100% solids, spray-applied, rapid-curing) and ShaliProtek PuR H (spray-applied hybrid polyurea) are the machine-sprayed grades for large-area, high-throughput work. Choose PuR L when access, detailing or the absence of spray rigs favours brush and roller application, and step up to the sprayed grades when speed and coverage dominate. As an authorised distributor of multiple brands, Space Arc can also position it against equivalent polyurea and PU systems from Fosroc, Sika and Dr. Fixit; for a permanently UV-exposed roof you might instead specify an acrylic or aliphatic-topcoated system from those ranges. Complement PuR L with the correct STP primer and STP thinner, and pair it with joint sealants and repair mortars where movement joints and substrate defects need treating before waterproofing.

Related Waterproofing products

View all Waterproofing products →