Foundation or basement suffering from groundwater, and a standard coating can't handle the pressure?

PandaCoat UnderBase 1K is a bitumen-modified polyurethane (PU) waterproofing coating built for underground and below-grade structures under high hydrostatic pressure: foundations, basement walls, tanks/reservoirs, green roofs. It combines the strength of bitumen with the flexibility of polyurethane — a seamless membrane resistant to up to 30m of water pressure.

UnderBase 1K Benefits

💪 The Power of Bitumen + Polyurethane
Combines bitumen's water resistance with polyurethane's flexibility — reliable protection against groundwater even under high hydrostatic pressure.

🌊 Reliable Waterproofing for Moving Structures
A seamless membrane with 1000% elongation at break — handles structural movement and crack widening without leaking.

🌡️ Wide Temperature Range
Works from -40°C to +80°C (briefly up to 150°C for 15 min) — retains elasticity and adhesion in any climate.

🖌️ Easy to Apply
One-component formula — apply with a brush, roller or spray gun in 2-3 coats, no mixing required.

What It Is

A one-component, bitumen-modified polyurethane coating that cures with atmospheric moisture into a firm, flexible, waterproof membrane (watertight up to 30m of water column, certified to UNE-EN 1504-2:2005). Built for waterproofing UNDERGROUND structures. Colour — black.

⚠️ Important limitation: UnderBase 1K is NOT suitable for permanent open UV exposure — it MUST be covered (with soil, tiles, a protective layer, etc.). Using it as a final, exposed surface is NOT permitted.

⚠️ Important safety information: this product is classified as hazardous under CLP Regulation (EC) No 1272/2008 — Acute Tox. 4, H312+H332 (harmful in contact with skin/if inhaled), Eye Irrit. 2, H319, Skin Irrit. 2, H315, STOT RE 2, H373 (may cause damage to organs through prolonged exposure), STOT SE 3, H335 (may cause respiratory irritation), with the additional statement EUH204 (contains isocyanates — may cause an allergic reaction/sensitisation). PPE REQUIRED: gloves, safety goggles or face protection, a respirator, and protective clothing/footwear. Work in a well-ventilated area or outdoors.

Where To Use It

• Foundations, basement walls
• Tanks and reservoirs
• Balconies, terraces (covered)
• Green roofs, covered tunnels, bridges
• Car park decks
• Bathroom/kitchen floors under tiles

Technical Data

• Density: 1.30 g/cm³
• Shore A hardness: 60-70
• Tensile strength: 2.2-2.5 N/mm²
• Elongation at break: 1000%
• Service temperature: -40°C to +80°C (briefly up to 150°C, 15 min)
• Watertight up to 30m water column
• Certified to: UNE-EN 1504-2:2005
• VOC (Supply): 21% by weight (285.46 g/L) — contains xylene (solvent)
• UFI code: 0CUS-5VJ0-010K-QS85
• Cure time: surface skin 45-75 min, foot traffic after 12 hours, final cure 3 days

Source: TDS Lastoflex-PB-1K, DoP pb-1k, SDS UNDERBASE 1K (separate SDS for 1kg and 6kg).

How To Use

1. Surface preparation — clean, dry, free of loose material, avoid application in rain.
2. Reinforce seams and corners with ElastoSeal-PU or UnderBase REP sealant.
3. Primer — Primer VL for concrete, EP-W for damp concrete.
4. Apply in 2-3 coats (no more than 0.8 kg per coat to avoid air bubbles), with 45 min to 48 hours between coats. For demanding areas, use with 60 g/m² geotextile to improve mechanical properties and crack bridging.
5. Consumption: 1.1-1.3 L/m² (1.4-1.7 kg/m²).
6. MUST be covered (with soil, tiles or another layer) — not suitable for open UV exposure.

Note: use with appropriate protective equipment (gloves, goggles, respirator). This product is NOT suitable for permanent open exposure — it's a component of an underground/covered waterproofing system, not a final exposed surface coating.