0203 397 4067
0741 837 2281
Mon - Fri
Saturday
Sunday
7AM - 5PM
8AM - 12PM
Closed

EWI Pro Nano Drex Breathable Silicone Render

Last modified: 16.01.2026
EWI Pro Nano Drex Breathable Silicone Render

Moisture in walls is more than an inconvenience; it's a structural and health risk. A breathable render allows trapped moisture vapour to escape while still protecting the façade from driving rain. EWI Pro Nano Drex Silicone Render (EWI-077) is designed to deliver this balance, combining advanced silicone technology with independently tested vapour permeability, making it one of the most reliable breathable renders available for the UK climate.  

 

A breathable render allows moisture vapour that has built up inside the wall to pass outward through the render layer. This moisture is a result of everyday living: the steam from cooking, condensation from showers, heating and normal occupancy. Rain often takes the blame, but it’s not the only villain at work.   

If a render is not breathable, this moisture becomes trapped inside the wall. Over time, that trapped moisture can cause damp patches, mould growth, cracking and deterioration of masonry or insulation.   

Nano Drex Silicone Render allows walls to dry naturally while still preventing rainwater from penetrating the façade.  

Although the UK experiences periods of blue skies, its buildings must primarily contend with frequent rainfall, temperature variation and internal humidity. Nano Drex addresses these conditions by combining three key properties:   

  • High vapour permeability, allowing internal moisture to escape  

  • Water-repellent silicone technology, preventing rain ingress  

  • A flexible finish, reducing cracking caused by thermal movement 

This balance helps maintain healthy walls and reduces moisture-related problems over time.  

The vapour permeability of EWI Pro Nano Drex Silicone Render has been independently tested by the Technical and Test Institute for Construction Prague (TZÚS), an ISO 17025-accredited laboratory, in accordance with ČSN EN ISO 7783, the European standard for measuring water vapour transmission of façade coatings.  

Testing confirmed that Nano Drex allows moisture vapour to pass through the render efficiently, supporting natural drying of the wall structure.   

Test Item  

What It Means  

Nano Drex Result  

Water vapour permeability (ISO 7783) 

How easily moisture inside the wall can escape through the render  

High vapour permeability, supports effective drying of walls  

 

Tested in accordance with ČSN EN ISO 7783 by an ISO 17025-accredited independent laboratory (TZÚS Prague).  

Nano Drex allows moisture vapour to escape instead of trapping it. As a result it:  

  • Protect masonry, insulation and timber elements  

  • Improves long-term façade durability  

Dry walls perform better, last longer and require less maintenance.  

There’s a misconception that breathable renders welcome water, Nano Drex begs to differ. 

Rainwater is repelled at the surface and runs off the façade, while moisture from inside the wall can still pass outward. This makes Nano Drex suitable for exposed locations, including high-rainfall and coastal areas.  

When moisture becomes trapped inside walls, it can lead to freeze-thaw damage, surface cracking and premature render failure. Breathable silicone renders reduce this risk by allowing moisture to escape before it causes internal stress.  

Over time, this helps reduce cracking, maintain appearance and lower long-term maintenance requirements.   

  • Heritage or Listed Buildings: Maintains natural breathability in solid walls, preventing timber and masonry damage.  

  • Damp-Prone Walls: Prevents interstitial condensation and promotes natural drying. 

  • High-Rainfall or Coastal Areas: Combines hydrophobic protection with superior UK weather resistance.  

  • Premium Projects: Provides long-lasting, low-maintenance finish with UV resistance and flexibility.  

 

For homeowners, specifiers or developers seeking high-performance breathable silicone render in the UK, EWI Pro Nano Drex (EWI-077) offers unmatched vapour permeability, durability and moisture management. Protect your walls, improve thermal efficiency and reduce long-term maintenance with this scientifically engineered solution. Â