Epoxy waterproofing uses two-component epoxy resin systems to create a hard, seamless, chemically-resistant, impermeable barrier. Unlike flexible coatings, epoxy is rigid, extremely strong, and highly chemical-resistant — making it ideal for water tanks (potable), industrial floors, chemical / effluent tanks, basements, and areas exposed to abrasion or aggressive chemicals. It also serves as a high-strength grout for cracks, bolts and tile joints.
Indian epoxy systems follow ASTM / EN 1504 standards. Major brands: Dr. Fixit (Pidilite), Fosroc (Nitocote / Nitomortar), Sika (Sikafloor / Sikadur), MYK Laticrete, BASF Master Builders, STP, Asian Paints Apcolite.
Epoxy is a thermosetting polymer formed by mixing an epoxy resin (Part A) with a hardener (Part B). The chemical reaction (curing) produces a tough, rigid, glossy, impermeable solid that bonds strongly to concrete. Key properties:
| Type | Description | Use |
|---|---|---|
| Epoxy Coating | Thin protective coat (brush / roller) | Water tanks, walls, light duty |
| Epoxy Self-Levelling Floor | 2–3 mm self-smoothing | Industrial / clean room floors |
| Epoxy Screed / Mortar | Epoxy + aggregate, heavy-duty | Heavy traffic, repairs |
| Epoxy Grout | High-strength grout | Cracks, bolts, machine bases |
| Coal-Tar Epoxy | Epoxy + coal tar | Sewage, marine, immersion |
| Epoxy Tile Grout | Stain-proof joint filler | Bathroom / kitchen tile joints |
| Water-Based Epoxy | Low odour, breathable | Damp surfaces, primers |
| Epoxy Injection | Crack injection resin | Structural crack sealing |
| Property | Typical Value |
|---|---|
| Base | Epoxy resin + hardener (2K) |
| Compressive Strength | 50–100 MPa |
| Tensile Strength | 15–40 MPa |
| Adhesion to Concrete | > 2.5 MPa (concrete fails first) |
| Elongation | Low (2–5%) — rigid |
| Chemical Resistance | Excellent (pH 1–13) |
| Abrasion Resistance | Excellent |
| Water Permeability | Nil |
| Service Temp | up to 60–80 °C |
| Pot Life | 20–60 min (temp dependent) |
| Full Cure | 7 days |
| Lifespan | 10–20 years |
| Parameter | Epoxy | PU | Acrylic |
|---|---|---|---|
| Flexibility | Rigid (2–5%) | High (300–600%) | High (150–400%) |
| Chemical Resistance | Excellent | Good | Moderate |
| Abrasion / Strength | Excellent | Excellent | Low |
| UV Resistance | Poor (yellows) | Excellent (aliphatic) | Excellent |
| Crack Bridging | Poor (rigid) | Excellent | Good |
| Potable Water | Yes (food-grade) | Yes (some) | Limited |
| Best For | Tanks, floors, chemicals | Traffic decks, terraces | Exposed roofs |
| Cost | High | High | Low-Medium |
Epoxy excels in chemical resistance & strength but is rigid & UV-sensitive — use it indoors / immersed / for chemicals, not for exposed moving terraces (use PU / acrylic there).
| Brand | Products |
|---|---|
| Dr. Fixit (Pidilite) | Epoxy coatings, Pidicrete EP, Roff epoxy grout |
| Fosroc | Nitocote EP, Nitomortar, Conbextra EP grout |
| Sika | Sikafloor, Sikadur, Sikagard epoxy |
| MYK Laticrete | Latapoxy, SpectraLOCK epoxy grout |
| BASF Master Builders | MasterTop, MasterSeal epoxy |
| STP | Epoxy coatings & grouts |
| Asian Paints | Apcolite Epoxy, SmartCare epoxy |
| Krishna Conchem | Epoxy systems |
| Item | Cost |
|---|---|
| Epoxy Coating (per kg) | Rs 250 – 550 |
| Food-Grade Epoxy (per kg) | Rs 350 – 700 |
| Epoxy Self-Levelling (per kg) | Rs 200 – 450 |
| Coal-Tar Epoxy (per kg) | Rs 200 – 400 |
| Epoxy Coating Applied (per sqft) | Rs 40 – 90 |
| Epoxy Floor (2 mm, per sqft) | Rs 80 – 200 |
| Water Tank Epoxy Lining (per sqft) | Rs 60 – 140 |
| Epoxy Tile Grout (per kg) | Rs 350 – 900 |
| Epoxy Injection (per metre crack) | Rs 300 – 1,200 |
| Standard | Description |
|---|---|
| EN 1504-2 | Surface Protection Systems for Concrete |
| ASTM D638 / D695 | Tensile / Compressive Strength of Plastics |
| ASTM D543 | Chemical Resistance of Plastics |
| ASTM D4060 | Abrasion Resistance (Taber) |
| NSF 61 | Potable Water Safety |
| IS 9197 | Epoxy Resin Floor Topping |
| IS 3067 | Code for Damp-Proofing & Waterproofing |
| EN 13813 | Screed Material (epoxy floors) |
Epoxy waterproofing is the specialist choice where chemical resistance, strength and a hygienic seamless surface are paramount — potable water tanks, industrial & clean-room floors, chemical / effluent tanks and stain-proof tile joints. It is rigid (no crack-bridging) and UV-sensitive (yellows outdoors), so it is for indoor / immersed / chemical applications, not exposed moving terraces. Success depends on dry surfaces, exact mix ratios, proper prep and full curing.
For exposed terraces use acrylic or PU coatings; for water tanks combine epoxy with cementitious + crystalline; for below-grade use bituminous or self-adhesive membranes.