External Wall Insulation

Boards are available in thicknesses from 40mm-200mm, in 10mm increments. The thickness of board is determined by the U-value required. We can work this out for you, please contact our technical team for more information on 08703 330070 or email technical@netweber.co.uk

Weber can work out the U-value and condensation risk for you based on the whole wall build up.

You can use our U-Value Calculator, or find a generic U-value calculation table in the EWI Refurbishment Guide, but a full analysis is recommended. Please contact our technical team for more information on 08703 330070 or email technical@netweber.co.uk

No. Timber frame requires a ventilated and drained cavity and therefore any external insulation is giving no thermal benefit.

See weberend MT instead.

The number of fixings depends on the substrate and the fixing methodology of the chosen system. See relevant specification sheet.

The depth of the fixings is dependant on the substrate and the required pull out load. Contact our technical services department for advice quoting the project name and address, call 08703 330070 or email technical@netweber.co.uk

Yes - please consult your Operating & Maintenance manual. 

If using webertherm EPS, a spiral fixing can be used. Each fixing can hold approx. 5kg. Ensure there is a tight mastic seal in place to prevent water ingress.

Alternatively, there is an ISO-Dart fixing available to fix medium to heavy objects when using webertherm EPS, webertherm MFD or webertherm PHS. Unlike the spiral fixing, this fixing penetrates the substrate, again please ensure that a suitable mastic sealant is used after.

Different external wall insulation systems will use different finishes, for example webertherm XP is finished with webertherm M1 render.

Please view all colour charts here.

There are various types of insulation: webertherm EPS (expanded polystyrene), webertherm MFD (mineral wool), and webertherm PHS (phenolic).

You can choose from scraped texture, spray roughcast textured, light ashlar finish, synthetic finish, dry dash aggregate, brick effect or authentic brick slips.

Generally, cement based materials can be applied between 5°C and 30°C.  Freshly applied materials should be protected from excessive temperature (either very low or very high), direct rain and rapid drying conditions. Common to all cementitious materials, inclement weather or long periods of dampness will encourage the phenomenon of efflorescence (commonly know as lime bloom).

Weber External Wall Insulation Systems are installed by recommended contractors only, this is part of our BBA certification and guarantee for the system.

Renders & Decorative Finishes

All product and system datasheets are available from our Download Centre.

The minimum at which render can be applied is 5°C. At lower temperatures the possibility of water freezing may cause problems such as cracking and debonding of the render.

The maximum temperature at which render should be applied is 30°C. At higher temperatures the render would need to be applied in shaded areas, the substrate may need cooling with a mist spray of water.

For more information, please take a look at our technical bulletins, namely:

Coverage varies between the type of product and the thickness it is applied. Coverage information can be found on each product or system datasheet found in the Download Centre.

Coverage examples:

  • Bagged products: These vary from product to product, for example, weberpral M when finished at 15mm would cover approx. 1m², and weberend LAC used as the 6mm basecoat would cover approx. 3m²
  • Bucket materials: The buckets are generally 10L and range in coverage from weberplast TF approx. 5.5m² at 1.5mm and weber PR310 covers approx. 40m²

For more information, please use the Consumption Calculator found on each product page.

Weep holes are a standard architectural detail and are required as instructed by the architect.

Not directly. Render will not bond to a previously painted surface so you will need to either remove the paint or consider a decorative coating or an external wall insulation solution.

Yes. You will need to create a cavity between the main frame and the panel being rendered — see NHBC or TRADA website for details of this.  The render system weberend MT can then be applied to a suitable render board.

Weber do not have a designated block manufactuer.

The type of blocks used is important however, typically, a medium-density (1350–1450kg/m³, 3.6–7.3kN), general purpose, concrete block with a mortar cement:lime:sand ratio of 1:1:6 will satisfy these requirements. 

Movement joints are required by the substrate and should be followed through the render. Details of where movement joints are required can be obtained from the relevant codes of practice for masonry construction. If in doubt, advice from a structural engineer should be sought.

More information can be found in our Best Practice Guide

Yes. We have a BBA Certificate for weberpral M and NSAI Certificate for weberpral D.

Lime bloom is a natural phenomenon in cement/lime based products and is neither an application or product fault. For more details on causes and remedial action, take a look at our lime bloom technical bulletin.

Straight line cracking is not typical of render failure, but rather of the reflection in the render of a crack in the substrate. For more information and suitable remedial action, please look at our Maintenance of weberpral monocouche renders technical bulletin.

The date on the bag is the manufacture date. The shelf life will be on the bag and for most products is 12 months.

Tile Fixing Products

BS5385:1 states that wooden substrates are no longer suitable to tile directly to, therefore it would be advised to use a tile backer board.

Consumption calculators can be found on all of our product pages on our website. However, an approximate calculation can be obtained by this equation: 1.7kg x mm x m² and dividing by 25 — alternatively, use the Consumption Calculator on the weberfloor flex product page.

No, weberfloor flex is formulated with selected products and should not have anything added to it other than 5 litres of clean water.

Quartz tiles require a highly flexible adhesive. The ideal option is to use weberset plus with weber AD250, weberset pro lite - rapid can also be used if tiling onto floors.

weberset plus requires the use of weber AD250 admixture to be used for underfloor heating or under-tile warming.

This is dependant on the substrate, typically from a dilution you should get 0.2L/m² — this information can be found on the back of the packaging.

Ready mixed tile adhesives are for use on wall tiling only. The maximum tile size would be 30x30cm ceramic only, small porcelain can be used but precautions should be taken.

Plasterboard can take up to 32kg/m² for direct fix and if it is skimmed then this reduced to 20kg/m². Please allow 3.5kg/m² for adhesive and grout.

If you are using a cement based tile adhesive, please use weber PR360 to prime the walls first.

The appropriate PPE should be worn at all times when mixing and applying all materials, Low Dust Technology™ reduces the dust cloud, but there will still be some airborne particles so it is advised to wear a suitable dust mask.

Flooring Systems

weberfloor 4310 (and rapid-setting alternative, weberfloor 4320) are the two main products to use with underfloor heating and in most circumstances you would need to cover the pipes by at least 15mm, please check with our technical team for other applications by calling 08703 330070 or emailing technical@netweber.co.uk

At least 2 coats of primer are required. Primer must be applied by brush as opposed to roller or spray application.

All the datasheets for the products can be found by either visiting the relevant product page, or by searching in our Download Centre.

For normal drying products, follow the guidance of the manufacture of the adhesive/floor covering. This will generally require the floor to be below 75% relative humidity.  

The shelf life should be on the datasheet and the packaging. For most products, the shelf life is 12 months.

No, the date on the bags is the manufacture date.

Refer to the datasheet information. A flow table and ring should be used for machine mixing.

No, never add more water than recommended or try to re-mix material after its pot life.

Technical Mortars

Minimum: Any material that requires water should not be used where there is a possibility of the water freezing before initial hydration of the cement has taken place. BS 8000 states that 5°C is the minimum temperature at which cementitious materials should be used.

Maximum: The maximum temperature at which Weber recommends the use of its products is 30°C. If using above these temperatures please contact our technical department on 08703 330070 or by emailing technical@netweber.co.uk  

The actual minimum and maximum temperature at which each of our products can be applied are detailed in the datasheets at the Download Centre.

Coverage of materials are on the relevant data sheet found at the Download Centre.

For most products the coverage is quoted in litres — as a guide, 1 litre will cover 1m² at 1mm thick.

For example, Five Star Grout when mixed with maximum water addition will yield 14 litres of material. If the thickness is 14mm then one bag will cover 1m².

All coverage rates should be checked to ensure that a) enough material is ordered for any given project or b) too much material is not ordered.

All the relevant mechanical data for our products are outlined on the data sheet in the Download Centre. For more specific information please email technical@netweber.co.uk

Minimum and maximum thickness of application is detailed on the relevant data sheets in the Download Centre. For special requirements please email technical@netweber.co.uk

Click Compare to help you choose the right product for your project, if you need further assistance please email technical@netweber.co.uk