Argatherm Ultrafine

• Compressive above 3.0 N/mm²
• Flexural above 1.0 N/mm²
• Adhesion ≥ 0.50 N/mm²
• Fire class A1

Yield: 1.0 kg/m² per mm

Thickness: 0.5 mm minimum; max 1 mm per coat, 2 mm total

Coats: 2 coats of up to 1 mm, the second once the first is dry

Figures are planning estimates; actual use varies with substrate texture, application method and technique.

What is Argatherm Ultrafine used for?

Argatherm Ultrafine creates perfectly smooth white surfaces on interior and exterior walls. It goes over an Argatherm skim on Diathonite plasters, WATstop, new and old plasters and concrete.

Do I need a primer before applying Argatherm Ultrafine?

No primer is needed. Apply directly over properly cured Argatherm skim coat (wait minimum 24 hours after Argatherm application). The substrate must be clean, sound, and free of loose material.

What's the difference between Argatherm and Argatherm Ultrafine?

Argatherm is the base skim coat (grain size 0–0.6 mm) applied in a sandwich system with Polites 80 mesh. Argatherm Ultrafine is the final finishing layer (grain size 0-0.1mm) that creates the perfectly smooth white surface. Use Argatherm first, then finish with Argatherm Ultrafine.

Can it be painted?

Yes. After full curing (28 days minimum), Argatherm Ultrafine can be finished with breathable, vapour-permeable coatings to maintain the system's breathability. Compatible finishes include Decork Façade, Limepaint, and other breathable paints. Avoid low-permeability coatings.

How is it applied?

Mix with clean water (10-11 litres per 25kg bag) using a drill mixer. Let rest 5 minutes, remix, then apply with smooth stainless steel trowel. Apply in thin coats (maximum 1mm per coat). When still workable, finish with trowel for smooth surface. Typically requires 2 coats.

Can it be used in cold weather?

Apply only when air and substrate temperatures are between +5°C and +35°C. Temperatures outside this range in the 24 hours following application can affect curing and final performance. Protect from frost, rain, and direct sun for 48 hours after application.

How long before I can apply paint or finish coats?

Wait minimum 28 days for complete curing before applying coatings or paints. After 5-7 days, you can apply primer or fixative appropriate to your chosen finishing system.

Does it prevent mould?

Yes. The hydrated lime base provides natural antibacterial properties that help prevent mould formation.