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RAINSEAL BMW 250
- Old bitumen roof repair
- Leaking metal sheet roof
- Retaining wall waterproofing
- Pipeline and tank coating
High-performance, elastomeric acrylic-bituminous blended waterproof coating for a wide range of surfaces — concrete, steel, and chemically treated floors. A water-based, high-solids, cold-applied, single-component liquid membrane, ready to use straight from the pack. Recommended for terraces, sloped roofs, MS/ACC sheets, external retaining walls, bathrooms and toilets.
Specifications
Figures are controlled laboratory results. Actual site performance varies with substrate, temperature, humidity, application method and workmanship — please confirm the current product datasheet before specification.
Where to use RAINSEAL BMW 250: bituminous waterproof coating for roofs and retaining walls
RAINSEAL BMW 250 is a bituminous waterproof coating blended with elastomeric acrylic, for concrete, steel and chemically treated floors. This water-based, cold-applied acrylic bitumen waterproofing is a single component liquid membrane that is ready to use straight from the pack. It goes on by brush or sprayer and dries to a black coating.
Terraces & Sloped Roofs
Apply two coats by brush or sprayer.
MS/ACC Sheets
Cold-applied liquid membrane for sheet roofing.
External Retaining Walls
Water-based coating recommended for external retaining walls.
Bathrooms & Toilets
Sprinkle fine dry sand on the wet final coat if mortar follows.
Old Bituminous Roofs & Tarfelt (Repair)
Adheres to existing bitumen and tarfelt, used with Geo or glass fibre tissue.
Pipelines & Metal Storage Tanks
Coats steel pipelines and metal storage tanks.
Vehicle Underbody Coating
Used for corrosion protection on vehicle underbodies.
Concrete, Steel & Chemical-Treatment Floors
Single-component coating for concrete, steel and chemically treated floors.
If you are working out how to repair old bitumen roof areas, this liquid bitumen coating adheres to existing bitumen and tarfelt. Elongation is 500%, water absorption 0.5–0.8% and temperature resistance -5°C to +85°C. Each coat dries in 40–50 min, depending on climate. Dilute with up to 20% water and apply two coats. For more mechanical strength, embed Fibre Mesh or Geo Fabric after the primer coat and first coat, then apply two further coats over the fabric.
Armstrong Chemicals supplies RAINSEAL BMW 250 to sites across Telangana, Andhra Pradesh, Karnataka, Kerala and Tamil Nadu, including Hyderabad, Vijayawada, Bengaluru, Kochi and Chennai.
One Coating, Five Solutions
A single-component acrylic-bituminous membrane that repairs old bitumen roofs, waterproofs terraces and toilets, protects pipelines and storage tanks from corrosion, and even guards vehicle underbodies — one product across construction and industrial sites.
Get a QuoteWhy Single-Use Coatings Fall Short
Most waterproofing coatings are built for one job — a roof, a wall, a tank. Site teams end up stocking multiple products for work that could be done with one membrane.
The BMW 250 Advantage
One acrylic-bituminous membrane that repairs old bitumen felts, waterproofs terraces and toilets, and protects pipelines, tanks and vehicle underbodies from corrosion.
Built to Repair, Not Just Coat
Applied straight over old bitumen and tarfelt for repair work; used with Geo fabric, it's a seamless, overlap-free alternative to re-felting.
A Base Coat for the Whole Armstrong Range
Overcoatable with ROOFCOAT PU 400, RAINCARE PU/PU 370, RAINSEAL, RAINSEAL 200 and RAINSEAL RWC 902 — engineered to work as part of a layered system.
Choose Your Application System
Bitumen Felt Repair
Seamless repair of old bituminous roofs and tarfelt, reinforced with Geo / glass fibre tissue.
Built to Protect, Built to Repair
One membrane, built for construction sites and industrial assets alike.
Seamless Repair, No Overlaps
Used with Geo fabric, BMW 250 is a genuine alternative to tarfelt or APP membrane re-felting — with zero overlap joints.
Built for Wet & Dry Surfaces
A water-based, ready-to-use formulation that applies cleanly on both moist and dry substrates, curing to a tough, abrasion-resistant film.
Resists Water, Acids, Alkalis & Salts
Resists water, dilute acid, dilute alkali and salt solutions, with high resistance to UV light and weathering exposure.
From Roofs to Pipelines to Vehicles
One membrane for terrace waterproofing, toilet wet areas, pipeline/tank corrosion protection, and vehicle underbody coating.
How to Use
Dilute RAINSEAL BMW 250 with up to 20% water; apply by brush or sprayer.
For a primer coat, dilute with water in a 2:1 ratio wherever necessary.
Apply two coats for dependable, excellent waterproofing.
For increased mechanical strength, embed Fibre Mesh / Geo Fabric after the primer coat and first coat, then apply two further coats over the fabric.
If cement mortar or concrete work follows, sprinkle fine dry sand onto the wet final coat for extra bonding strength.
Applicable Areas
Packing & Storage
Available in 1, 5, 10 & 20 Litre packs. Shelf life of 12 months (one year) in original, unopened, sealed condition — store in a cool, dry place.
Safety Precautions
If it comes in contact with eyes, wash with plenty of water. If irritation persists, seek medical attention.
Overcoat Compatibility
Can be overcoated with ROOFCOAT PU 400, RAINCARE PU, RAINCARE PU 370, RAINSEAL, RAINSEAL 200, and RAINSEAL RWC 902 — built to work as a base layer in a larger waterproofing system.
Coverage Calculator
Enter your surface area to estimate how much RAINSEAL BMW 250 you need. Coverage rate: 50 sq.ft per litre per coat.
Product Brochure
Download Technical Datasheet
Full specifications, application systems, layering guides, and coverage tables.
Frequently Asked Questions
Ready to protect your structure?
Request a quote and your nearest Armstrong distributor will contact you directly.
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