Multiprime Undercoat

Multiprime Undercoat

Thermoguard Multiprime Undercoat is a versatile professional primer and undercoat designed to improve adhesion, opacity and finish quality across a wide range of interior and exterior surfaces.

Developed to provide a stable high-build foundation for decorative coatings, Multiprime Undercoat helps create a smoother more uniform surface while improving the long-term durability of the final finish coat.

The product is suitable for timber, metal, plaster, masonry and many previously painted surfaces, making it ideal for both refurbishment and new-build decorating projects.

What It Does

• Provides a strong adhesion-promoting basecoat.
• Improves finish coat opacity and uniformity.
• Helps create a smoother decorative finish.
• Supports long-term coating durability.
• Suitable beneath a wide range of decorative systems.

Why Choose Multiprime Undercoat?

• Multi-surface compatibility: suitable for timber, plaster, metal and prepared painted surfaces.
• Improved topcoat appearance: helps reduce flashing and uneven absorption.
• Strong adhesion properties: designed to improve coating stability on difficult substrates.
• Interior and exterior capability: suitable for a wide range of decorating environments.
• Professional finish quality: creates a smooth foundation for gloss, satin and eggshell systems.

Where It Can Be Used

• Interior timber and joinery
• Exterior woodwork
• Metal railings and gates
• Plaster and plasterboard
• Previously painted walls and woodwork
• Masonry and cement-based surfaces
• Commercial and residential projects

Ideal For

• Professional decorating projects
• Interior refurbishment work
• Exterior maintenance programmes
• Joinery finishing systems
• Commercial property decoration
• Preparing surfaces for specialist Thermoguard coatings
• Projects requiring improved topcoat performance and durability

Performance Benefits

• Designed to improve adhesion of finish coats.
• Provides strong opacity and coverage.
• Helps reduce uneven substrate absorption.
• Creates a smoother and more consistent decorative finish.
• Suitable for use beneath gloss, satin, eggshell and specialist systems.

Finish Compatibility

• Suitable beneath decorative gloss finishes.
• Compatible with eggshell and satin systems.
• Can be used beneath selected Thermoguard specialist coatings where specified.
• Improves finish consistency on porous and repaired substrates.
• Designed to support long-term finish durability.

Application Information

• Suitable for brush, roller or spray application.
• Apply evenly at the recommended coverage rate.
• Allow sufficient drying time before overcoating.
• Do not apply in excessively damp or cold conditions.
• Stir thoroughly before and during application.

Coverage & Drying

• Coverage varies depending on substrate condition and porosity.
• Touch dry times depend on temperature and ventilation.
• Normally recoatable after sufficient curing.
• Additional coats may be required on highly porous surfaces.
• Ensure adequate airflow during drying.

Surface Preparation

• Surfaces must be clean, dry and free from grease, dust and contamination.
• Loose or unstable coatings should be removed before application.
• Glossy surfaces should be lightly abraded to improve adhesion.
• Repair cracks and damaged areas before priming.
• Metal surfaces should be free from corrosion and oxidation.

Suitable Substrates

• Timber and joinery
• Plaster and plasterboard
• Prepared ferrous metals
• Previously painted surfaces
• Masonry and cement-based substrates

Good To Know

• Correct preparation is essential for maximum adhesion and durability.
• Always allow primers and undercoats to fully cure before applying finish systems.
• Highly porous substrates may require additional priming.
• Different topcoat systems may require specific primers or preparation methods.
• For specialist fire-rated systems, always follow Thermoguard specification guidance.

Need Better Adhesion & A Smoother Decorative Finish?

Many finish coat problems begin with poor surface preparation or unstable substrates. Multiprime Undercoat is designed to create a stronger more uniform foundation that helps decorative systems perform and look better for longer.