Cornerstone SuperTherm Plaster 3.75kg bag

SuperTherm Plaster

A ready mixed ultra-lightweight and low density fibred plaster to enhance the thermal insulation of solid walled masonry suitable for use within a two coat render application.

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More about SuperTherm Plaster

Cornerstone SuperTherm is a dry ready mixed lime plaster designed as an ultra-lightweight and low density insulation layer and fibred basecoat for internal applications within a minimum of a two-coat plaster application. Available in the colour off-white.

Engineered with precision to provide a revolutionary internal lime plaster with an unmatched insulating performance. Utilising an innovative foamed aggregate with a nanometre pore structure that prevents the directional flow of heat that results in heat loss through the building envelope while providing moisture management. Available as standard with fibres and a high-purity Calcium Hydroxide with pozzolan.

Well-suited for projects requiring an ultra-lightweight plaster with exceptional insulating properties, with a measured K Value of 0.04, a 50mm application will improve the U value of a solid wall by more than 75%.

  • Our most insulating lime plaster
  • Functions as a thermal layer and basecoat plaster
  • Designed to improve insulation and reduce heating costs
  • Highly vapour permeable to support moisture management
  • Reduces relative humidity and condensation
  • Improves indoor air quality and thermal comfort
  • Free from halogens and heavy metals
  • Can be applied at 50mm per pass as a high-build plaster
  • Ultra-lightweight for less demanding levelling and finishing
  • A viable solution for Part L legislation
Materials:
Non-Hydraulic Lime, Foamed aggregate
Mix Ratio:
1:3 including fibres
Binder:
CL90
Aggregate:
Foamed aggregate
Work:
Plastering, Insulation
Coverage:
A 3.75kg bag covers up to 1.5m2 at 10mm thickness
Yield:
A 3.75kg bag yields up to 15 litres
Colours:
Off-White
Use:
Internal
Coat:
Insulation Layer, Not a topcoat
Standard:
BS EN 998-1: 2016
Fire Rating:
B, s1, d0
Application:
Manual, Specific Sprayers
Data Validation:
3 months ago
NBS Source:

Suitable for internal use, where the binder strength is appropriate for the host background or surface.

Relevant for applications requiring an insulation layer, SuperTherm can be applied directly to the wall as a basecoat plaster within a suitable plaster system, eliminating the need for boarded systems. SuperTherm requires a topcoat finish, including SuperTherm Finishing Plaster, Promix Fine Topcoat or Promix Medium Topcoat. Appropriate for various project types, including conservation, renovation, or sustainable construction.

A 3.75kg bag yields up to 15 litres of lime render or plaster and covers up to 1.5m² at a 10mm thickness. Consumption rates will change based on how even the background is and suction. On-site trials are advised for the best yield indication for your specific project.

As this contains natural foamed aggregates, there may be variations in colour, texture, and shape. While these variations are minimal, when colour consistency is crucial, we strongly advise each elevation is completed using material from the same batch.

Supplied in 3.75kg polythene-lined and colour and batch-coded paper bags for easy identification on-site. Palletised for ease of transport, storage, and handling.

Do not use in temperatures below 5°C or above 25°C, or if freezing conditions are predicted within the following few weeks, including wind chill. We always advise following best practices for curing and protecting fresh mortars. Protect from adverse environmental conditions, including frost, rain, direct sunlight and drying winds.

Store in covered and dry conditions, protected from environmental conditions, including water, damp or frost and clear from the ground. Always reseal packaging if product is still present.

Always read the available documentation before use. See the Download Documentation section below for more detailed product information, application guidance and datasheets.

Independent Real-World Testing

Up To 75% U-Value Improvement

Thermal performance testing with the award-winning Elemental Cubeâ„¢ and GreenTEG U-value kits resulted in a 75% improvement in a challenging Grade II* listed granite building. Conducted as part of a government funded pilot project with the Cornwall Conservation Department and English Heritage.

APPLICATION THICKNESS

50mm

Apply up to 50mm per pass to speed up application and reduce time on site.

THERMAL CONDUCTIVITY

λ=0.04W/m2K

Reduces heat loss or gain making the building more energy efficient.

VAPOUR PERMEABILITY

μ=4.2

Highly breathable to manage moisture and reduce damp and decay.

Thermal image of the wall of the market house

The Market House thermal performance pilot project

Discover how cutting-edge technology documented the thermal performance improvements of this prestigious Grade II* listed civic building.

Explore The Project


What our clients say

SuperTherm Basecoat being levelled with a straight edge

Learn how to get the application right with Master Plasterer Sean Wheatley.

From prep to curing and aftercare, Sean covers how to apply SuperTherm quickly and effectively.

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