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BKK Eco 5kg tub

Diasen BKK Eco

Stock code: DBKK
Manufacturer code: unknown

Diasen BKK Eco

Breathable water based and colourless rain repellent coating

5 litre

Excl VAT


Excl VAT

In Stock: Usually delivered within 3-4 working days

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  • Product Overview
  • Technical Details
  • Installation guide

Main purpose

Stops water being absorbed by the wall without affecting breathability.

Use it on

Any stone or masonry external wall.


BKK Eco is a colourless water repellent coating that can be applied to exterior walls. It prevents water absorption due to wind driven rain, is breathable and lets moisture dry out ensuring the wall’s insulation performs at its highest level. BKK Eco prevents algae growing and helps reduce the risk of salt deposits forming. It protects and extends the durability of the wall by preventing water ingress. If water is not absorbed, it can’t freeze and degrade the wall surface. By keeping the wall dry for longer, this in turn increases the thermal performance of the wall.

Where to use it

BKK Eco can be used on exposed stone, masonry walls and plasters from water absorption due to wind driven rain. It has no visible effect on the wall so is an ideal protective coat for solid stone or masonry walls that are insulated internally with Diathonite Thermal Plaster, Calsitherm Climate board or Gutex Thermoroom.

It may also be used internally to protect Diathonite plastered walls when the bare plaster is not finished with Argacem HP, Decork or Cork Render (for example when the plastered wall will have timber paneling installed over the top). It may also be applied over Argacem HP where the homeowner does not wish to paint the finish plaster. Please note, natural variations in the consistency of the finish plaster will then be exposed. To attain the most consistent finish it is recommended to paint with a breath finish such as Auro natural paint.  You may be interested to read an article in Listed Heritage Magazine.

How it Works

BKK prevents water ingress from the external wall’s surface while preserving breathability.

What it does

It lets moisture dry out to ensure the wall and its insulation performs at its highest level. When a wall is insulated internally with Diathonite, Calsitherm or Gutex Thermoroom; BKK ECO is the perfect choice for protecting the external side of the walls.  

Why we love it

As water does not stay on the BKK Eco treated wall (it runs straight off), it cannot evaporate on the surface to leave any dissolved solid behind (e.g. salt from sea water) or remain long enough to feed algae. It therefore prevents algae growth, stains, and deposits on the wall. It also prevents frost damage to the wall as water can’t freeze and damage the surface if repelled rather than absorbed.


  • Enhances insulation performance
  • Water based and colourless
  • Breathable
  • Quick and easy to apply
  • Solvent free
  • Protects the wall by repelling rain and water


  • Ideal for walls exposed to wind driven rain by allowing water to run off the surface. 
  • Prevents algae growing and staining on the wall
  • Prevents damage caused by water freezing within the wall (freeze-thaw).
  • Maximises the performance of the wall’s insulation.
  • No visible change of appearance when applied with no detrimental effect to the wall.
  • Allows any moisture in the wall to evaporate. 
  • Ensures full compatibility with other breathable solutions used on the wall.
  • Easy to apply by brush or can be spray applied (with appropriate equipment).
  • Safe to use on heritage buildings.


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Technical Details

5 litre

Key Technical Data

5 °C to 35 °C
15 m²
4 hours
5 litre
Moisture management, Wind/Weatherproofing
Externally, Internally
Historic or listed building, Massive construction (thick concrete), Solid stone, block or masonry walls, Solid walls (block or brick), Solid walls (stone, brick or masonry)
Cool and dry

Technical Datasheet

Material Safety Datasheet (MSDS)

Declaration of Performance (DOP)

Featured Article

Installation Guide

How to Install

Application of BKK Eco is very easy and perfect for a D.I.Y project as there is no need for a specialist installer. BKK Eco can be applied with a brush or sprayed on with a pressure sprayer. Typically 2-3 coats are applied until the surface is saturated. 

In normal conditions (20°C, 40% relative humidity) BKK Eco dries in 4 hours. You should wait 1 hour between each coat and make sure the previous coat is still wet when you apply the next coat. In colder temperatures or higher humidity, the drying time will be longer.

Exposed brick coated with water on the surface which has been repelled by BKK Eco
Exposed brick coated with BKK Eco

Hints & Tips

If used internally over Argacem HP finishing plaster, BKK Eco must be sanded off if you wish to paint the surface in the future.

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