External Wall Insulation
The Different Finishes

As stated in our Introduction To EWI, any external wall insulation system consists of insulation and a reinforcing basecoat followed by a finish of choice. The purpose of this feature is to introduce a number of EWI finishes and options to demonstrate the versatility of EWI.

Thin Coat Renders

Perhaps the most popular finish, one coat thin coat renders include silicone, silicate, acrylic, mineral renders which are generally applied to the thickness of the grain. Usually this means the thickness will be anything between about 0.6 and 3mm with the most popular by far being 1.5mm. The smaller the grain the smoother the texture but beware going too smooth as you’re going to need to achieve near perfection in the hand applied receiving basecoat – a light texture will mask any slight imperfections and always look good.

These finishes generally come pre-mixed and ready to trowel apply and float finish. A single coat application is usually all that’s required although some will require a primer and certain mineral thin coats may require an additional coating. All are through coloured too and come in a very wide range of colours (often hundreds) and can also me matched to any specific colour which may be required by the project.

Such finishes are quick and easy to apply and low maintenance too – certainly the addition of silicone within many of these thin coat renders makes them very easy to keep clean.

Thick Coat Renders

By thick coat renders we typically mean through colour mineral renders which arrive dry packed for mixing with water before application to around a maximum thickness of around 15mm.

Thick coat renders can be spray applied to give a heavy, rough cast texture or hand scraped using a nail float to give more of a scratch render texture.

These finishes are considerably more colour restrictive due to levels of pigments which can be added to the render mix – typically whites and pastel colours only. Being thicker they provide greater impact resistance.

Dry Dash

Dry dash remains a very popular finish within certain regions – particularly in parts of Scotland, Wales and the South West.

By using a thick coat coloured render as a base receiver local aggregate (stome chips) can be sourced, purchased and thrown into the wet render in the traditional hand dashing manner of throwing the aggregate into the wet basecoat render.

The use of different coloured basecoats and different coloured aggregate can create some very different effects.

Brick Effect Finishes

When it comes to building in the UK, we are still a nation of brick lovers. As such there are a number of ways to cost effectively create the effect of a brick finish onto an EWI system without the need to build a wall! There are a variety of ways that this can be achieved:

Brick Slips: thin slips of bricks (in effect a tile) which can be adhesively fixed onto an EWI basecoat and mortar joints replicated with specialist external grouts. The effects can be indistinguishable to the real thing.

Lightweight Imitation Brick Slips: Very light, flexible and thin imitation brick tiles which sometimes come bound into ready to hang panels for ease and speed of application. Adhesively fixed to the EWI basecoat and mortar joints replicated with specialist grouts.

Brick Effect Render: This involves using through colour renders to create the appearance of bricks. A wet base coat is applied in the desired colour of the mortar joints over which a second coat of render is applied in the desired colour of the bricks and textured before being cut back to expose the “mortar” and create the effect of brickwork. Additional effects can be then created by the use of paint or resin stains.

Stone and Wood Effect Finishes: In a rapidly developing industry we are now able to replicate stone effect finishes and even the effect of timber cladding by using specialist finishing techniques.

EWI Finishes – There’s No Limits

Quoins, wall bands, sills and trims can be created using exterior mouldings or by innovative render applications and, with the use of different render textures, effects and colours there’s no limits to what can be created with an EWI system.

Taking a look at some of the INCA EWI Case Studies or the historical INCA Award Winners will give you some inspiration!

EWI Finishes

There really is no limit as to what finish you can create using an external wall insulation system.

A wide range of different textured renders in unlimted colours along with brick effect, stone effect, dash along with a range of profiles makes for a designers dream!

Start by making contact with an INCA EWI system member who will work with you to create your ideal design, put together the specification and connect you with their trained INCA member installer network or contact your local INCA contractr direct.

You can access the INCA member database here >.

External Wall Insulation
All You Need To Know