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Insulating Render & Plaster

Internal / External Wall Insulating Render

ProofTherm insulating render/plaster is a 100% natural, breathable and easy to use insulating plaster that is suitable for use on the vast majority of internal and external wall wall structures.

Suitable for almost all substrates, ProofTherm provides unrivalled flexibility, especially in the treatment of older properties where its ability to breathe (vapour permeability) gives it a major advantage over standard insulation materials.

ProofTherm insulating plaster is an inert mineral product containing zero VOC’s. Advanced manufacturing and a unique formula have enabled us to create a high-performance, lightweight and breathable insulation solution for the 21st Century.

Call us now on 01622-535009 to place your order or for more information

ProofTherm is suitable for use on external walls, internal walls and is also manufactured as a screed for insulating floors

Its primary function is to provide insulation which it achieves by combining lightweight aggregates of igneous rock that have millions of air bubbles trapped in their structure, with a traditional mineral render. The result is a lightweight render/plaster that can be applied to most walls to increase the thermal and acoustic performance of the structure.


ProofTherm is a high-performance internal wall plaster that provides a number of benefits in one product: Thermal insulation, fire resistance and sound insulation.

Whether as a stand-alone insulation measure or as part of a system, internal wall insulating plaster can help regulate the thermal comfort of the building and reduces the energy demand for heating and cooling. Its high level of vapour permeability helps prevents the build-up of damp and mould.

Essential Characteristics Performance Method of test
Thermal Conductivity λ10 dry (W/m.K) T1 (0.09 W/m.K) EN 1745:2012
Reaction to fire A1 EN ISO 1182, ISO 1716
Adhesion(N/mm2 and fracture pattern (FP)A,B or C 0.1 N/mm2 FP:B EN 1015 - 12:2000
Compressive Strength CS II EN 1015 - 11:2000/A1:2007
Capillary Water Absorption W1 (0.3 kg/m2.min⁰.⁵) EN 1015 - 18:2014
Water vapour permeability (μ) 6.27 µ EN 1015 -19:2000/A1:2006
Dry bulk density (kg/m3) 450 kg/m3 ±%10 EN 1015 -10:2001/A1:2007
Sound insulation (db) 23db (3cm/500hz) EN ISO 10140-2


ProofTherm internal wall insulating plaster is prepared and used in much the same was as any mineral based plaster.

One 20kg bag of ProofTherm internal wall insulating plaster covers approximately 2.2m2 of internal wall when applied at a depth of 20mm.
Careful preparation of the surface to be insulated is, as always, very important. For optimum adhesion the wall should be free of dust, grease and any loose material and should then be prepared with ProofBase acrylic primer.

ProofTherm is primarily an insulating material and needs to be finished off with a standard plaster to achieve the desired decorative finish.

For full instructions on how to use ProofTherm, please download our guide.

20mm of ProofTherm applied to an uninsulated brick wall will increase its Thermal Resistance by 250%

Manufactured to European Standard EN-998-1:2016

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+44 1622 535009


ProofShield Ltd
Energy Works
Gas Road
United KIngdom

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