Weberpral Monocouche is a cult classic when it comes to thick coat renders. It’s renowned for creating a crisp, clean finish in a range of natural colours. In terms of installation, this product is highly versatile in the textures that it can create. Whether it’s a scratch finish, tyrolean or a dry dash finish, Weber monocouche can achieve it.

At EWI Store, we’re very excited to have recently started stocking Weberpral Monocouche render, so we’ve put together a basic guide on how to install the render to create a scraped finish!

What is Weberpral M?

Weberpral M is a decorative, through-coloured, thick coat render. It is a very versatile product, as it can be finished in different ways to achieve a range of textures and finishes such as roughcast, scraped, dry dash or ashlar. It is a BBA Approved polymer-modified render that comes as a dry-mix in 25kg bags – a favourable choice when compared to sand and cement.

Substrate Preparation

Prior to application of the Weber Monocouche, you need to ensure that the substrate is stable, clean, suitably dry, sound and free from anything that may affect adhesion. The substrate needs to have the correct amount of suction; too little and the render won’t adhere properly; too much suction and the render will fail. You can test the suction of the substrate by spraying water onto it and visually inspecting the rate at which it is absorbed.

If you find that the substrate has a high suction, it needs to be lightly sprayed with water and then tested again. This should be repeated until it has the correct suction. Be careful not to soak the wall excessively, as this can cause a reduced adhesion of the render.

For very smooth surfaces, we recommend applying Weberend Aid as a key coat. This should be applied using a hawk and trowel, or using an open-hopper spray gun. A tight layer should be applied across the substrate before it is textured using a well-loaded roller.  

Preparation of Weber Monocouche

A 25kg bag of Weberpral M Monocouche should be mixed with 5-5.5 litres of clean, potable water using an electric paddle mix. Weber tends to recommend that you use as little water as possible (erring towards the 5-litre mark) so as to give a workable consistency.

Application of Weber Monocouche

Weberpral M should be applied in either one or two passes using either a spray machine or by hand using a trowel. The typical finish achieved using the Weber monocouche is a scraped finish; for this technique, the minimum thickness that should be achieved is 18mm, with a maximum thickness of 28mm.

Weber recommends the use of Fibreglass Mesh for their monocouche system. The mesh needs to be embedded into the middle of the render – it shouldn’t make contact with the underlying substrate but equally, it needs to be embedded deep enough to avoid becoming visible once the render has been scratched back.

When applying the render in two passes, we recommend applying the first pass and ruling it off to a perfectly flat finish, before going on to apply the next pass 1-2 hours later, before the first has fully hardened. The two layers should fuse together as one coat.

To achieve the textured finish, the render should be scratched back 3mm before it has fully hardened – therefore a 28mm thickness would become 25mm, and an 18mm thickness would be scratched back to 15mm.

If you’re looking for an approved installer to carry out the work for you, fill out the form below and we will be in touch. We upload blog posts every Tuesday and Thursday, so keep up to date with our blog and social channels to find out more!

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