External Wall Insulation

External wall insulation is a composite cladding system comprised of suitable insulation and waterproof coating which is applied to all the external walls of a building. External Insulation is by far the simplest, easiest and most energy efficient way of thermally upgrading your home insulation without a massive disruption to homeowners as all works can be carried out whilst the occupants are still living in their properties.

Red Letter Supplies are agents for the Soltherm system which is NSAI certified and is regularly tested by an external accredited research body. We do not only sell products, but the complete solution which includes all of the services that go with the product, technical support and training.

We stock the full range in our Longford warehouse which ensures the products are close to the market where they are required.

How it works

  • External Wall Insulation involves fixing insulation to the outer surfaces of walls to that the house is effectively ‘wrapped’ in insulation
  • The insulation is then covered with a render, giving your home a fresh new look
  • Our Soltherm solutions give you over 300 colours to choose from and suit all types of buildings
  • Installing External Wall Insulation is the single biggest contributor to improve your BER rating

How it's fitted

1. Adhesive

Soltherm SA adhesive is applied to the insulation material using a ribbon and dab method to ensure stability.

2. Insulation material

The insulation material is then applied to the exterior of the property in a staggered pattern to ensure maximum strength.

3. Corner bead

Reinforced beading is applied to all corner areas. Two individual fixings are then used to secure the insulation to the wall.

4. Basecoat

A even layer of premium Soltherm basecoat such as Soltherm UB is applied to the entire insulated area ensuring extra impact resistance.

5. Glass fibre

Soltherm glass fibre mesh (145g/m2 or 158g/m2) is embedded into the basecoat to further strengthen the structure and prevent cracking.

6. Basecoat

A second layer of basecoat is then applied to the glass fibre mesh.

7. Primer

The Soltherm primer is then applied to the basecoat to ensure correct adhesion of the finish coat. This can be white or tinted.

8. Finishing Coat

Soltherm glass fibre mesh (145g/m2 or 158g/m2) is embedded into the basecoat to further strengthen the structure and prevent cracking.

Soltherm Premium Acrylic System

The most popular insulation system, durable, tried and tested for years, which provides the best value for money.

The Soltherm Premium Acrylic System is one of our very best sellers. This insulation system meets all basic performance requirements at high level. This universal solution is suitable for virtually any type of buildings, and in particular for single family houses, vulnerable to dirt and harsh weather conditions.

  • The best value for money
  • Can be pressure washed
  • Weather resistance – rainfall, frost, snow, sun
  • High flexibility
  • Good impact resistance
  • Unlimited colour range

Adhesive to EPS boards

Soltherm SA

EPS Boards

Soltherm EPS



Glass Fibre Mesh

Soltherm 145g/m2 or 158g/m2

Base Coat

Soltherm UB

Key Coat

Soltherm SNP Colour

Finishing Coat

Soltherm AF-P




SOLTHERM BC-P QUICK No Priming Base Coat