Thermaldry Anti-Condensation Coating – Thermal Insulating Paint for Cold Walls

Thermaldry Anti-Condensation Coating is a high-performance thermal insulating paint designed to reduce condensation, prevent mould growth and improve the comfort of cold interior walls. Formulated with millions of hollow glass beads, the coating increases surface temperature and creates a thermal barrier that delays the formation of condensation by up to 60% longer than standard emulsion paint.

This advanced coating is water-based, breathable, water-repellent, and suitable for application over most interior surfaces including plaster, brick, masonry, timber, concrete, metal and existing paint finishes. Ideal for homes, commercial buildings and high-moisture areas.

Advantages

• Reduces condensation on cold walls and ceilings

• Helps prevent black mould, mildew and damp spots

• Thermal insulating effect using hollow glass bead technology

• Water-repellent, breathable and washable finish

• Suitable for bathrooms, kitchens, bedrooms and external-facing walls

• Easy to apply by brush or roller

• Can be used over existing paint or wallpaper*

• Improves occupant comfort and energy efficiency

• Compatible with most decorative finishes

*Ensure surfaces are clean, sound and free from loose coatings.

How Thermaldry Works

The hollow glass microspheres inside Thermaldry act like tiny insulating chambers.

These beads:

• Reflect and retain heat at the surface

• Increase wall temperature

• Slow the cooling of interior wall coatings

• Shift the dew point away from the wall surface

The result?

Significantly reduced condensation, fewer cold-spots, and less opportunity for mould to form.

Typical Applications

• Cold external-facing walls

• Rooms prone to condensation: bathrooms, kitchens, shower rooms

• Bedrooms with cold corners or thermal bridges

• Ceilings above bathrooms or kitchens

• Over lintels and window reveals

• Areas with a history of mould or mildew

• Social housing, rented properties, HMOs and student housing

• Commercial and industrial environments

Application & Coverage

• Apply using brush or roller

• Typical coverage: 10–12 m² per 5L tub depending on surface (3L tubs also available)

• Apply two coats for optimal thermal performance

• Dries to a durable, breathable, water-repelling finish

• Can be painted over with most decorative emulsions once cured

• Surfaces must be clean, dry and free from mould (treat mould first with a suitable biocide)

Technical

Frequently Asked Questions

What is Thermaldry Anti-Condensation Coating used for?

Thermaldry is a thermal insulating, water-repellent coating designed to raise the surface temperature of cold walls and reduce condensation, damp spots and mould growth. It is ideal for problem areas such as bathrooms, kitchens, external-facing walls and ceilings.

How does Thermaldry reduce condensation and mould?

The coating contains millions of tiny hollow glass beads that act like micro “Thermos flasks”, reflecting heat back into the room. This increases the wall’s surface temperature so moisture is less likely to reach dew point, helping to prevent condensation and the mould that follows.

Where can Thermaldry be applied?

It can be used on any clean internal surface including plaster, painted walls, masonry, concrete, timber, metal and plastic. It is especially useful for cold corners, external-facing walls, lintels above windows and rooms prone to moisture such as kitchens and bathrooms.

Can I apply Thermaldry over existing paint or wallpaper?

Yes. As long as the surface is clean, sound and well-prepared, Thermaldry can be applied over previously painted surfaces or wallpaper without affecting its performance.

How long does Thermaldry delay condensation?

Testing shows that walls coated with Thermaldry can take up to 60% longer to develop visible condensation compared to untreated surfaces, helping rooms stay drier and more comfortable.

Is Thermaldry breathable?

Yes. The coating forms a water-repellent yet breathable film, allowing moisture within the wall to escape while preventing surface condensation.

How many coats do I need?

Two coats are recommended for best performance. Each coat should be applied evenly and allowed to dry fully before decorating or applying other finishes.

Can it be painted over?

Yes — once fully dry, Thermaldry can be finished with most decorative paints without reducing its thermal or anti-condensation performance.