EWI Pro Premium Basecoat (EWI-225) – 25kg

Premium Basecoat (EWI-225)

EWI Pros Premium Basecoat (EWI-225) is their finest basecoat adhesive. It is breathable, high strength, durable and can be used for a range of applications. This versatile product works perfectly as a basecoat and adhesive for Mineral Wool, Kingspan K5 and Wood Fibre insulation boards. Its also an excellent choice as a standalone render system, suitable for a wide variety of substrates including render carrier boards.

Formulated with white Portland cement and a high concentration of polymer-modified binders, this adhesive delivers exceptional strength compared to standard basecoat adhesives like EWI-220. Once the basecoat has dried it provides an incredibly strong and flexible reinforcement layer; we therefore highly recommend this product for ‘render only’ systems. 

You can use our Premium Basecoat for the following two purposes:

• An adhesive used to create the reinforcement basecoat layer in render only or Mineral Wool, EPS, Kingspan K5 and Wood Fibre EWI systems
• An adhesive used to fix Mineral Wool (Rockwool) to a substrate.

No matter if you’re using Premium Basecoat as an adhesive or as a basecoat, preparation couldn’t be simpler - the process is exactly the same. The Premium Basecoat comes as a dry mix in 25kg so needs to be mixed with clean, cold water ( >5.9 litres) prior to use. 

We suggest filling a large bucket with the correct quantities of water prior to adding the dry basecoat mixture. Using a paddle, mix the basecoat with water until you have achieved an even consistency mortar and then leave the bucket for 5-10 minutes after mixing. Before using the adhesive mix again.

Application

When applying Premium Basecoat as the basecoat layer, spread it evenly onto the substrate using a notched trowel. Next, embed overlapping strips of Fibreglass Mesh, ensuring the mesh sits in the centre of the basecoat layer. Once embedded, the layer should achieve a total thickness of 6mm.

When using Premium Basecoat as an adhesive for insulation boards, there are two application methods: either cover the entire surface of the board with a notched trowel, or apply the adhesive around the perimeter with three dabs across the centre.

• Primer: EWI-301 or EWI-310 if a key is required
• Application temperature (air, substrate, materials): from +5°C to 25°C
• Time of usability after mixing with water: approx. 2 hours (temp. +20°C)
• Water mix proportions: approx. >5.9 litres of water per 25 kg of dry mix
• Quantity to be used:
  • Fixing insulation panels of foamed polystyrene and reinforced layer on foamed polystyrene: approx. 4-5 kg/m2
  • Fixing insulation panels of Mineral Wool and reinforced layer on Mineral Wool: approx. 5-6 kg/m2

Storing Premium Basecoat

This is supplied in powder form in a 25kg paper bag. Store in a cool, dry place and protect from moisture. Shelf life: up to 12 months from the date of manufacture.

Premium Basecoat Coverage Rates

• Basecoat/Adhesive – 25kg/2.5m2

Render only:

• (Brick/block) – 25kg/2.5m2
• (RCB) – 25kg/3-3.5m2
• (Insulation) – 25kg/3-3.5m2

Frequently Asked Questions

What is the difference between Premium Basecoat and other basecoats?

The main difference between Premium Basecoat and other basecoats, such as EPS Basecoat Adhesive (EWI-220), is that Premium Basecoat contains white portland cement and a high concentration of polymer-modified binders and synthetic fibres, delivering flexibility, higher crack resistance, and improved durability.

How much water do I need to mix Premium Basecoat with?

You should mix approximately 6 litres of water per 25kg bag of Premium Basecoat. There is a time of usability after mixing with water of approximately 20 hours at a temperature of +20°C.

What temperatures can I use Premium Basecoat in?

Premium Basecoat can be applied in a temperature range of +5°C to +25°C. The average drying time for Premium Basecoat is approximately 12-48 hours, depending on weather conditions. The drying period may be significantly longer in low temperatures and high relative humidity.

Do I need to use a substrate primer before using Premium Basecoat?

We highly recommend that you prepare the substrate using our EWI-301 Water-Based Substrate Primer (or EWI-310 Universal Primer if a key is required) before applying the basecoat layer. This will improve the Premium Basecoat’s adhesion to the substrate.