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Premium Basecoat (EWI-225) – 25kg

Brand:EWI Pro
(6 customer reviews)

£19.36 Excl. VAT

  • Dual-purpose, can be used as a basecoat and adhesive
  • High strength
  • Vapour permeable
  • High elasticity

999 in stock

Premium Basecoat (EWI-225)

Premium Basecoat is breathable, high strength and durable. EWI-225 is  EWIPro’s finest basecoat adhesive, and can be used for a range of solutions. For example, this product is ideal as a basecoat/adhesive for Mineral Wool, Kingspan K5 and Wood Fibre insulation boards, or as a render-only solution for a range of substrates, including render carrier board.

The adhesive contains white Portland cement and a high concentration of polymer-modified binders – making it stronger than other basecoat adhesives, such as 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.

Premium Basecoat is prepared in the same way regardless of whether it is being used as a basecoat or an adhesive for fixing the Mineral Wool insulation boards to the substrate. 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. Use a paddle mix to mix the basecoat with water until you have achieved an even consistency mortar. Leave the bucket for 5-10 minutes after mixing, and then mix again before using the adhesive.


If using the Premium Basecoat for the basecoat layer, apply the basecoat using a notched trowel to the substrate. Then embed overlapping pieces of Fibreglass Mesh – the mesh should sit within the middle of the basecoat layer. Once embedded the basecoat layer should be 6mm in total.

If using the Premium Basecoat to fix insulation boards to the substrate, there are two application options. For example, the product can either be applied to the whole surface of the insulation board using a notched trowel, or applied to the perimeter of the insulation board with 3 dabs across the middle.

  • 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

Comes in powder form in a 25kg paper bag. Store in a cool, dry place. Avoid ingress of water. 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

  1.       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.

  1.       Can I use Premium Basecoat as an adhesive?

Premium Basecoat can be used to fix Mineral Wool (Rockwool) slabs to a substrate as it has very good adhesion to Mineral Wool. 

  1.       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.

  1.       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.

  1.       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.

Weight 25 kg

6 reviews for Premium Basecoat (EWI-225) – 25kg

  1. F Baumann

    Has to be the best adhesive, comparable to the StoArmat Novo or the StoArmat Levell basecoats. Trust me, I have installed Sto, Baumit and other German systems.

    A 25kg bag can typically do 5 to 6 metres for us of the basecoat layer. You can mix it according to instructions but we tend to use our own judgement through experience. The powder is cream and when mixed with water comes nicely when applied with the trowel.

    It can be used for mineral wool and eps, but I just use it on eps systems all the time, but I dont waste the ewi-225 for sticking boards, I tend to use the ewi-220.

  2. Simon Grade

    Great gear this. 6-8mm on top of insulation boards with mesh and render goes on great too.

  3. Jayesh

    Use the premium adhesive on our last job. It is great. would recommend. It is very strong, mixes well and goes on easy.

  4. Steven

    Good as a basecoat for silicone render systems, gives a durable result.

  5. Charlie Dennon

    By far the best basecoat I’ve worked with. It sticks to anything, is easy to work with saves days at a time on jobs as it doesn’t need primers. Strongly recommend.

  6. Jearl

    A premium product, but having used HP12 for years and more recently Weberend LAC, this ewipro premium basecoat sponge floats beautifully and dries solid as a rock. If you have the budget would strongly recommend.

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