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Diathonite Evolution cross section
Diathonite Evolution used to create curves and follow contours of stone walls

Diasen Diathonite Evolution

18kg Bag

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The calculation is based on spray applying the plaster to an even, level wall. For hand application with a trowel, add approx. 15% to the estimate below. The calculation is for guidance only and does not include material needed to level (dub out) the wall.
m2 of Diasen Diathonite Evolution
mm thickness
  • Product Overview
  • Technical Details
  • Installation guide

Main purpose

Insulating the building and maintaining the breathability of the wall/ceiling.

Use it on

Internal or external solid stone or masonry walls and ceilings. Can also be applied to wood-based panels/sheathing, laths and plasterboard that have been primed with Diasen Aquabond Primer. 


Diathonite Evolution is a fully breathable lime-based insulating plaster made from cork, clay and diatomaceous earth.  It is highly breathable and helps walls in older buildings dry out thanks to its capillary active nature. Diathonite Evolution thermal plaster can be used internally or externally on solid stone or masonry walls and ceilings. It should be applied to exposed stone or brick after any gypsum plaster has been removed.  It can also be applied on wood-based panels, lath and plasterboard that have been primed with Diasen Aquabond.   

Where to use it

Diathonite Evolution thermal plaster can be used internally or externally and is ideally suited for the restoration and insulation of Historic/Listed buildings or any building with solid stone or masonry walls.

What it does

Diathonite Evolution is an insulating plaster that can help regulate moisture to manage damp and humidity in solid walls often found within older buildings. Please note, Diathonite Evolution does not cure penetrating damp. Prior to application, any existing damp problems must be fully resolved.

In a typical installation, applying 50 - 75mm of Diathonite Evolution will improve the thermal performance of the wall by 3.5-4.5 times.  This thickness is the most cost-effective way to provide a significant thermal improvement to the wall.

The mechanical strength and elasticity are provided by the clever combination of natural ingredients.  Elasticity reduces the risk of micro-cracking for a long-lasting durable finish.

Diathonite Evolution is supplied in 18 kg bags.  There are 60 bags per pallet.

How it works

The Diathonite system is breathable and capillary active. It lets vapour pass through and actively transports moisture from the structure of the building helping the wall and building dry out. It regulates humidity and prevents condensation and mould growth.

Why we love it

The main ingredients are lime NHL3.5, cork, clay and diatomaceous earth. These all-natural ingredients are sympathetic to the conservation requirements of listed buildings and will contribute to LEED credits.

Evolution dries much faster than a traditional lime plaster; usually it only takes one third of the time which works out at approximately 2mm per day.

Unlike dry board systems, Diathonite Evolution is malleable and flexible when being applied. This gives many beautiful aesthetic options for rounded window reveals and curved wall surfaces that follow the contours of the underlying stone or brick, especially in stone cottage refurbishments. A more modern style finish can also be achieved when required.

Diathonite Evolution is not only a highly effective stand-alone insulating system but also an ideal levelling coat for uneven walls prior to using breathable insulating board systems like Gutex Thermoroom and Calsitherm.

It is non-combustible so will not burn or emit smoke.


  • Excellent thermal conductivity
  • All-natural ingredients
  • Beautiful finish
  • Safe and eco-friendly
  • Breathable and Capillary active
  • Easy Application
  • High Elasticity
  • Easy thermal bridge solution
  • Excellent drying times
  • Fire Protection
  • Antibacterial Properties


  • 50mm of Evolution improves the thermal performance of a wall by approximately 3.5 times.
  • Dual function plaster; can be used to level walls and to insulate.
  • Natural cork and lime provide breathability, thermal insulation and elasticity while also maintaining the unique characteristics of the wall.
  • Can be used internally and externally allowing walls to breathe and balance room humidity.
  • Up to 10 times more elastic than traditional plasters reducing the risk of cracks.
  • Provides a simple and easy solution to eliminate thermal bridges.
  • Can be sprayed-on or applied by hand. An experienced lime plasterer or DIY enthusiasts can install it with no special training. 
  • Dries much faster than traditional lime.
  • Euroclass A1 fire resistance, does not burn or emit smoke so improves fire safety of buildings.
  • Alkalinity of lime prevents the formation of mould and condensation.
  • Complies with Building Regulations.


How soon after applying Evolution externally can I use Decork over the top?

Diasen Evolution must be completely dry before applying the Diasen D20 Primer and Decork. Evolution is dry when the entire area is light grey in colour (all over) and is firm to the touch. The time to dry varies based on the weather conditions, humidity and thickness of the Evolution; generally, allowing 1 day per 2mm of thickness will be sufficient. In dry warmer weather, a thickness of 25mm can dry in about 10-12 days. In colder wet weather, this might be considerably longer (2 or more weeks).

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Technical Details

Key Technical Data

Technical Datasheet

Material Safety Datasheet (MSDS)


Environmental Product Declaration (EPD)

Declaration of Performance (DOP)

Installation Guide

Brand/Manufacturer Brochure

Featured Article

Installation Guide

How to Install

The minimum application thickness for Diathonite Evolution is 15mm. In thicknesses over 60mm, the reinforcing fibreglass mesh Polites-140 is required. On a ceiling, the typical application thickness is up to 30mm and a reinforcing mesh must always be used. Diathonite can be built in 15-25mm layers to the required overall thickness, typically one layer is applied per day.

When used internally, Diathonite Evolution should be finished with a layer of Argacem HP, a breathable lime-based finishing plaster and breathable paint like Auro (if required). If the external face of the wall is not rendered and only the inside was insulated, we would recommend a breathable rain repellent like BKK Eco to be used externally to limit the amount of moisture absorbed by the wall externally.

For external insulation, Diathonite Evolution may be finished with Argacem HP followed by a breathable primer and paint. Alternatively, a textured finish can be achieved by finishing with Decork which is available in a range of colours.

For projects over 100 square meters, your installer may apply Diathonite Evolution using a spray pump machine. This is quicker than hand applying and uses approximately 10-15% less material because the plaster is not being compacted by a trowel.  An experienced trained installer is always recommended for larger projects.

Diathonite Evolution being applied via a spray pump on an internal wall.
Diathonite Evolution being applied with a spray pump. Spraying uses 10-15% less material because the plaster is not being compacted by a trowel.

Hints and Tips

All coverage/yield figures quoted are based on application to a smooth level surface. They are for guidance only and do not include material required to level (dub out) the walls.  

On walls with white salt deposits (efflorescence) or high moisture content, Diathonite Deumix+ can be used to speed up drying and act as a salt inhibitor.  Diasen Regularisation could also be used as the first layer of plaster (underneath the Diathonite Evolution) on walls with severe salt issues when required.

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