External wall render is a protective and decorative coating applied to the outside of a building. It can change the appearance of a property while helping create a finished external wall surface.
Render is also commonly used as part of external wall insulation (EWI) systems. In this type of application, the render is not simply applied directly to the insulation board. It forms part of a complete system that can include insulation boards, adhesive, mechanical fixings, reinforcing mesh, basecoat, primer and a final decorative render.
What Is External Wall Render Used For?
External wall render has two main purposes: protecting the wall surface and providing a finished appearance.
Depending on the type of render selected, it can provide a textured or smooth-looking finish and is available in different colours and finishes. This makes rendering a practical option for both new construction and renovation projects.
Render can be applied to suitable prepared mineral substrates, while certain products are specifically designed for use with external thermal insulation systems.
For example, Infinity PM supplies ATLAS render products designed for exterior applications and EWI systems. The range includes silicone, silicone-hybrid and acrylic render products for different project requirements.
How Does Render Work With EWI?
External wall insulation involves installing insulation to the outside of an existing wall before applying the finishing layers.
A typical EWI system may include:
- EPS or other suitable insulation boards
- Base tracks and profiles
- Adhesive
- Mechanical insulation fixings
- Fibreglass reinforcing mesh
- Basecoat
- Primer
- Decorative external render
The render therefore forms the visible outer layer of the system.
The insulation board provides the thermal insulation, while the basecoat and reinforcing mesh help create a suitable surface for the final render. The render then provides the external finish.
This is why it is important to consider the whole EWI system rather than selecting a render separately from the other materials.
Types of External Wall Render
There are different types of external render, and the right choice depends on the substrate, system and finish required.
Silicone Render
Silicone render is a popular option for external wall finishes. ATLAS thin-coat silicone render is available through Infinity PM and is designed for use on suitable external surfaces and EWI systems.
The ATLAS range describes its silicone render as water-repellent, vapour permeable and suitable for creating a modern decorative finish.
Silicone Hybrid Render
Silicone hybrid render combines properties designed for external decorative and protective finishes. Infinity PM supplies ATLAS Silicone Hybrid Render, which is recommended for surfaces insulated with EPS or XPS boards.
It is available in a range of colours, allowing the external appearance of a building to be selected to suit the project.
Acrylic Render
Acrylic render is another option for decorative and protective thin-coat finishes. ATLAS Cermit N-100, for example, is designed for suitable exterior and interior applications, including ETICS systems using polystyrene boards.
Different render types should not be treated as interchangeable. Always check the manufacturer's system requirements and substrate recommendations before selecting a product.
Why Is the Basecoat Important?
The basecoat sits underneath the final render in many EWI systems.
After insulation boards are installed, a suitable adhesive or basecoat can be used with reinforcing mesh to create a reinforced layer. The final decorative render is then applied over the prepared surface.
This means the basecoat, reinforcing mesh and render all have important roles within the finished system.
Infinity PM supplies products such as ATLAS Grawis U EPS Basecoat Adhesive and fibreglass reinforcing mesh alongside its range of render products.
Choosing the Right External Render
Before choosing a render, consider the following:
1. What surface are you rendering?
The existing substrate or insulation system will affect which render products are suitable.
2. Is the render part of an EWI system?
If you are rendering over external insulation, make sure the selected render is compatible with the complete EWI system.
3. What finish do you want?
Different renders can provide different textures, colours and visual effects. Consider the appearance required for the finished façade.
4. What are the conditions around the building?
Buildings near busy roads, urban areas or other locations exposed to dirt may have different practical requirements. Product recommendations should be checked against the manufacturer's guidance.
5. Are the system components compatible?
The insulation, adhesive, basecoat, mesh, primer and render should be considered together rather than as completely separate products.
External Wall Render from Infinity PM
Infinity PM supplies external wall render, EWI materials and building supplies for trade projects across the UK.
The range includes ATLAS render systems, EPS insulation boards, reinforcing mesh, basecoat adhesives, primers, insulation fixings and other EWI components.
For projects involving external wall insulation or façade renovation, choosing the right render is an important part of creating a suitable finished wall system. The best product depends on the substrate, insulation system, required finish and manufacturer's recommendations.
Frequently Asked Questions
Is external wall render the same as plaster?
No. External render is designed for exterior wall applications, while plaster is generally associated with internal surfaces. They have different uses and product requirements.
Can render be applied over EPS insulation?
Suitable render systems can be used over EPS insulation as part of an appropriate EWI or ETICS system. The complete system and manufacturer requirements should always be checked.
Does EWI need a render?
Many EWI systems use a decorative external render as the final façade finish, although the exact finish depends on the selected system and project specification.
What is used underneath the external render?
For an EWI system, the layers can include insulation boards, adhesive, fixings, reinforcing mesh, basecoat and primer before the final render is applied.
Where can I buy external wall render?
Infinity PM supplies ATLAS external render products and a range of EWI materials for trade projects in the UK.