Gutter leaking, a crack or seam letting water through, where a thinner coating wouldn't reach?

PandaCoat TopBase ST Paste is a thick, non-drip silicone paste for sealing seams, cracks and joints. Used as a complement before or after a TopBase ST/TopBase ST Fiber coat, or standalone for spot repairs on gutters, chimneys and joints, whenever you need a fast, reliable seal without applying a full coating.

TopBase ST Paste benefits

🧴 A thick paste, not a liquid
Ideal for vertical cracks, chimney joints and gutter seams where a thinner coating would simply run off – scoop it out with a spatula or brush and press it straight into the gap.

🔧 One coat, no primer
Primer is usually not needed – clean the surface and apply straight from the tub with a spatula in one coat, avoiding rainy days.

🌦️ Weatherproof in any conditions
Once cured, like TopBase ST, it resists UV rays, rain, snow and temperature swings.

🔩 Suited to spot repairs or prep work
Seal a single cracked gutter seam in minutes, or reinforce joints and corners before coating the whole roof with TopBase ST.

What it is

A single-component, silicone-based sealant paste – the same TopBase ST chemistry in paste form. Cures with atmospheric humidity into a strong, elastic, waterproof seal. This is NOT a standalone roof coating – it's a complement to the TopBase ST/ST Fiber system, or a spot sealant. Available in grey or white.

Where to use

• Gutter seams and joints, chimney flashing
• Vertical cracks and gaps where a thinner coating would run off
• Skylight edges, roof joints, corrugated panels
• Caravan, trailer, outbuilding and garage roofs
• Bitumen felt seams, before or after a TopBase ST coat
• Concrete, metal, ceramic and wood surfaces

Technical properties

• Relative density: 1.25 (1342.3 kg/m³, SDS)
• Dynamic viscosity: 6500 cP (thicker than TopBase ST Fiber)
• Non-flammable (flash point >60°C)
• VOC (Supply): 1.33% by mass (17.89 g/L) – virtually solvent-free
• Classification per CLP 1272/2008: not hazardous (only EUH208 supplementary statement)
• Curing: surface skin forms after ~2 hours

Source: PandaCoat TOPBASE ST PASTE Safety Data Sheet (SDS, v.3). This version has no separate technical data sheet (TDS) or Declaration of Performance (DoP/ESD).

Application

Clean the surface of dirt, dust and grease. Primer is usually not needed for typical repairs. Apply the paste with a spatula or brush straight from the tub, pressing it into the crack, seam or joint, and smooth it flat. Avoid applying on rainy days.

Applied in one coat – the concept of multiple coats doesn't apply as it would for a full coating. If extra protection is needed, cover with a TopBase ST coat once the paste has skinned over.

Note: this is a complement to the TopBase ST system, not a standalone roof waterproofing coating – use it for seams, cracks and spot repairs, or as substrate prep before the main TopBase ST/ST Fiber coat.