Frequently Asked Questions

For a 500-bay multi-storey car park in Noida with exposed open-sided decks and ramps receiving direct sunlight and monsoon rain, what complete floor coating system should be specified using MC-Bauchemie products, and why is polyurethane the correct topcoat choice over epoxy?

A multi-storey car park with exposed open-sided decks and ramps in Noida represents one of the most demanding environments for a concrete floor coating system in the Indian climate. The structure is exposed simultaneously to very high UV radiation (ultraviolet index in Noida in summer exceeds 10 on the WHO scale — the highest hazard category), heavy monsoon rainfall (accumulation of water on horizontal slab surfaces between drainage points), wide diurnal and seasonal temperature swings (surface temperatures on black-painted or dark-coated car park decks can reach 60 to 65 degrees C on a May afternoon, dropping to near 5 degrees C on a January night — a swing of 55 to 60 degrees C), carbonation from vehicle exhaust gases concentrated in enclosed or semi-enclosed deck levels, chloride from tyre-tracked salt on visiting vehicles from road-salted highways, and impact and abrasion from turning vehicles and dropped metal objects. The complete MC-Bauchemie floor coating system for this application comprises four layers applied in sequence. Layer 1 — surface preparation. Prepare the concrete deck slab by shot-blasting or scarifying to achieve a surface profile of ICRI CSP 4 to 5 (open, roughened surface with no laitance) and remove all dust and loose material by vacuum. Seal all construction joints and cracks wider than 0.5 mm with MC-Bauchemie flexible polyurethane sealant before priming. Layer 2 — MC-Dur 1225 moisture-tolerant epoxy primer. Apply one coat of MC-Dur 1225 solvent-free epoxy primer at 0.3 to 0.4 kg per square metre by roller to the prepared, dry slab surface. The primer seals the concrete pores, consolidates any surface dust, and provides a high-adhesion interface for the subsequent coating layers. For exposed decks in Noida, the primer also provides a moisture vapour barrier to mitigate the risk of coating blister formation during the monsoon season when high ambient relative humidity (above 85 percent RH) can create sufficient moisture vapour pressure differential to lift a film coating from the concrete. Allow the primer to cure for 4 to 6 hours at 25 to 30 degrees C before the next coat. Layer 3 — MC-DUR 1150 epoxy body coat. Apply one or two coats of MC-DUR 1150 solvent-free epoxy floor coating at 0.4 to 0.5 kg per square metre per coat as the main body coat. The epoxy body coat provides the primary chemical resistance (oil, fuel, and brake fluid from vehicles), the required compressive and abrasion strength for forklift and vehicle traffic in internal levels, and the main film thickness for crack coverage. The epoxy body coat is not used as the final exposed topcoat because it will yellow under UV on the open deck levels. Apply the final epoxy coat at a non-slip texture (broadcast dry quartz aggregate at 100 to 150 g per square metre into the wet coat and allow to cure — this provides anti-slip resistance on the ramp and entry deck levels) for ramps and entry levels. Allow the epoxy body coat to cure for 12 to 24 hours before the PU topcoat. Layer 4 — MC-Floor PU topcoat. Apply one to two coats of MC-Floor PU aliphatic polyurethane topcoat at 0.25 to 0.35 kg per square metre per coat by roller over the cured epoxy body coat. The PU topcoat provides UV stability — the colour, gloss, and film integrity of the PU topcoat will be maintained for 5 to 10 years under the Noida UV conditions that would yellow an epoxy topcoat within 3 to 6 months. The flexibility of the PU topcoat (elongation greater than 50 percent) accommodates the thermal expansion and contraction of the exposed deck slab through the full 55 to 60 degree C annual temperature swing without cracking. The aliphatic PU topcoat also provides the final chemical resistance barrier against the dilute acid pH of monsoon rainwater (which carries dissolved CO2 and SO2 from Delhi NCR air, producing carbonic and sulphurous acid that attacks cementitious surfaces but not PU coatings). Total system thickness is typically 0.5 to 0.8 mm — sufficient for anti-carbonation protection, crack coverage over hairline cracks up to 0.2 mm, and mechanical durability for 10 to 15 years service life under car park conditions with regular cleaning and maintenance. Space Arc Engineering provides complete system design, product supply, and applicator referrals for multi-storey car park coating projects across Delhi NCR and Uttar Pradesh.