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Weber Saint-Gobain - Official website of the company

weberpral M

weberpral M
weberpral M

Product Benefits

  • Through-coloured external render
  • Water resistant
  • For application to most suitably prepared brick and blockwork 
  • weberpral M offers a variety of ways to achieve distinct architectural features. 

One Coat, Through-Coloured, Water Resistant Monocouche Render 


About this Product

weberpral M is a one coat, ready mixed, cementitious, weather resistant, external decorative, through coloured render, suitable for most types of brick or blockwork. Factory produced from carefully selected raw materials for consistency of product, it only requires the addition of water on site. The through colour and one coat features allow fast application with shorter programme periods, thereby reducing associated scaffolding and site costs and permitting the completion of ground works at an earlier stage. weberpral M has been awarded an A+ Green Guide Rating as defined in the BRE Global 2008 Green Guide to specification.

Features and Benefits

  • One coat for fast application and short programme periods
  • Water resistant
  • Through-coloured for low maintenance - decoration not required
  • A+ Green Guide rating
  • Factory produced for consistency of proportioning
  • Ready mixed - only water required to be added on site for ease of use
  • Formulated to be spray applied by render pump for faster application
  • BBA approved certificate no. 05/4268
  • Algae resistant

Colours & Finishes

weberpral M is available is a range of 24 colours. 6 standard colours and 18 special colours.  Specifiers should consult the weberpral M Colour Chart and, whenever possible, obtain samples prior to specification.

Technical Data

weberpral M has been designed for spray application and can be applied up to 28mm thick in two passes. Manual application is also possible.

weberpral M has excellent weather resistance and durability, whilst allowing the structure to breathe.

Substrates must have a good mechanical key suitable for rendering. weberend aid must be used to provide an artificial key on substrates such as smooth concrete.

Technical Services

Weber's Customer Services Department has a team of experienced advisors available to provide on-site advice both at the specification stage and during application. Detailed specifications can be provided for specific projects or more general works. Site visits and on-site demonstration can be arranged on request.

Technical Helpline
Tel: (01525) 722110
Fax: (01525) 718988

Sales Contact

Sales, England & Wales
Tel: (01525) 722100
Fax: (01525) 718988

Sales, Scotland
Tel: (0141) 445 0121
Fax: (0141) 445 0122

Sales, Ireland
Tel: (028) 9335 2999
Fax: (028) 9332 3232


Product Datasheet

Material Safety Datasheet

System Certification

Declaration of Performance (DoP)

Send or download the documents

You can either send the documents to an email address, or download it

Technical drawings

  • BIM models



Scaffolding must be independently tied to allow for an uninterrupted application. Any faults in the structure, particularly those which may lead to moisture penetration must be rectified.

To avoid dampness and discolouration rendering should be avoided below DPC and within 150 mm of ground level.

All surfaces must be sound, clean, suitably dry and free of any material which may impair adhesion. The substrate should be suitable for rendering with a designation III mix (1:1:6).

Arrises and feature stops may be formed using clean straight timber battens.

Alternatively, suitable beads may be used but, with a scraped finish, these will be evident and must be accepted as a feature. Please note that scraped renders may, during the scraping process, tend to spall away from the nose of some angle beads. Refer to weber's Technical Department for advice on suitable profiles.

Mask as required. Edging tape must be removed before the material has dried.

Expansion joints should be included as required by the substrate and carried through all applied materials.

Do not apply to gypsum plaster or previously painted surfaces.


weberpral M should be mixed with 5 - 5½ litres of clean water using either a suitable render spray machine, drill and whisk or tumble mixer.

To ensure colour consistency, the materials required for complete and adjoining panels should be of the same batch number or be thoroughly mixed together before use.

For best results, use as little water as possible and mix to give a workable consistency.

Note: weberpral M may stiffen on standing. Re-mix product to regain a workable consistency but do not add any more water.


To maintain colour consistency, panels should be completed in sequence around the building.

Spray roughcast
Depending on the required finished thickness, a first pass is spray applied to a minimum thickness of 10 mm and ruled level. A second texture pass is applied between 1 and 2 hours after the first to form a single monolithic coat with a minimum thickness of 15 mm. Total finished thickness should be between 15 and 25 mm.

Scraped finish
weberpral M should be applied to the suitable substrate in a one or two-pass operation to a minimum thickness of 18 mm, or to a maximum thickness of 28 mm. (2 - 3 mm will be removed by the scraping process to give a finished thickness of minimum 15 mm, maximum 25 mm.) It should then be ruled level and allowed to harden for between 5 and 16 hours. (Sometimes a longer period may be necessary depending on weather and background conditions.)

When weberpral M is green (set but not fully hardened) it should be scraped with a circular action using a scraping tool. It is essential that this is done carefully and evenly, ensuring all laitance is removed and that no part is missed. Thoroughly brush down the surface of the scraped finish using a soft bristle brush.

Dry dash finish

Apply weberpral M by render pump or traditional methods in the usual manner. For 15 mm render thickness apply an initial pass to a nominal 10mm, rule level. When sufficiently hard but still green typically between 1 & 16 hours later depending upon climatic conditions and suction provided by the substrate apply a secondary butter/dash receiver coat 5 mm in thickness. (please note for a 20 mm finished thickness apply a 15 mm initial pass, followed by 5 mm under the same guidance).

Attempting to dash into a full thickness of render, not applied in layers may lead to slumping and loss of the aggregate into the render.

A flowing edge must be maintained to the render which must not be allowed to skin over before the stone is applied.

On completion aggregate should be lightly tamped into the render with a wood or plastic float to ensure that a good bond is obtained.  All aggregate should be washed and reasonably dry.  The optimum size of aggregate is between 4-8mm.

Ashlar features
Apply weberpral M in two passes to an initial thickness of between 20 mm and 28 mm to allow for an Ashlar recess from 2mm deep up to a maximum of 10 mm. Ensure a minimum of 15 mm thickness is maintained at the base of the recess for sheltered to moderate exposure. Rule level and spatula flat. When the material is still green, scrape the surface as detailed in the guidance notes for scraped finish.

Immediately after scraping, mark out and cut the Ashlar effect using weber Ashlar tools to produce the desired profile. Thoroughly brush down the surface of the render using a soft bristle brush. weberpral M will set and gain hardness in a similar manner to conventional renders.

Protection from unfavourable weather conditions should always be provided during application and early age curing.

Good practice
Do not apply:

  • If frost is forecast within 24 hours of use
  • In damp/wet conditions
  • In temperatures below 5°C or above 30°C
  • On elevations in direct sunlight or where the substrate is hot


Curing with a fine spray of clean water may be necessary during rapid drying conditions.

In hot climates, curing as above is essential for 3-5 days after application.

Packaging and H&S


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weberpral M is supplied in 25 kg paper sacks.

To achieve a finished thickness of 15 mm, coverage is approximately 25 kg per m2.

Note: These estimates take no account of wastage and will vary according to the type of surface involved and method of application.

Storage and Shelf Life

When stored unopened in a dry place at temperatures above 5°C, shelf life is 12 months from date of manufacture.

Health and Safety

Contains cement (Contains chromium (VI). May produce an allergic reaction). Harmful by inhalation. Irritating to eyes and skin. Keep out of the reach of children. In case of contact with eyes, rinse immediately with plenty of water and seek medical help. After contact with skin, wash immediately with plenty of soap and water. Wear suitable protective clothing, gloves and eye/face protection. Keep out of the reach of children. For further information, please request the Material Safety Data Sheet for this product.