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The Newton Waterproofing Index is a unique specification tool in the construction industry, providing specifiers and designers with a scoring system through which it is possible to accurately assess the level of risk and potential success involved in a waterproofing design.

To assist the specifier in deciding on the correct waterproofing specification, the Newton Waterproofing Index (or ‘NWI’) is a unique waterproofing specification tool which has been developed as a means of assessing the ability of a waterproofing specification to successfully protect an earth-retaining or below-ground structure. This assessment is based both upon the type of structure involved, and the type/s of waterproofing being used.

The purpose of the Newton Waterproofing Index is to give specifiers an accurate understanding of the potential success of different specifications and builds, as well as helping to guide them through the myriad of different waterproofing products and combinations available in the market.

Visually, this assessment is then represented as a NWI ‘score’ that can be used to judge each waterproofing specification.

The Scoring System

The scoring system works in conjunction with the British Standard for waterproofing, BS 8102:2022, which defines the three types of desired internal environment as Grades 1a, 1b, 2 and 3.

As part of the 2022 update to BS 8102, Grade 1 has now been split into Grade 1a and Grade 1b, and further definitions have been added to Grade 2 and Grade 3 – this includes the statement that “Ventilation, dehumidification or air conditioning [is] necessary” to achieve a Grade 3 environment.

Combined Newton Waterproofing Index Logos for Scoring Waterproofing Designs

The NWI score is awarded by our panel of experienced waterproofing design specialists, and audited by Newton’s independent insurer. The result is an accurate reflection of the chances of success of that specification.

Once assessed, designs are appointed with a scoring range due to the fact that the effectiveness of the waterproofing depends on the competency of the installation.

The lower end of the range indicates the score that can be achieved with imperfect workmanship. A safer specification will result in a good waterproofing score at the lower end of the range, showing that it is achievable even if the installation is not performed to the highest standard. The upper end of the range indicates the standard that can be achieved by those that are trained in the installation.

The wider the potential scoring range, the higher the risk that an imperfect installation will negatively affect the waterproofing.

For ease, these scoring ranges are also presented on a scale:

Newton Waterproofing Index Scoring Scale for Waterproofing Specifications and Designs

The blue marker on the scale indicates the expected NWI score that can be achieved when ventilation is not included. The purple marker indicates a Grade 3 environment that can only be achieved via ventilation, dehumidification or air conditioning, appropriate to the intended use, as per British Standard 8102:2022.

Complete Waterproofing Solutions

Newton’s library of waterproofing Solution Sheets are an integral specification tool within the Newton Waterproofing Index, each bringing together key product information, NBS Clauses and 3D drawings into one complete resource, including individual NWI scores for easy comparison.

Sample Waterproofing Specification Sheets for Structural Waterproofing

Ready-Made Solution Sheets

View a variety of Newton’s ready-to-use solution sheets, depending on the nature of your project and the type of structure being used, including blockwork, contiguous piles, existing structures, ICF, reinforced concrete, secant piles, sloping sites, and underpinning.

These downloadable resources offer a glimpse into the wide array of waterproofing solutions available for different types of structures. They serve as a comprehensive waterproofing specification tool, encompassing crucial product details ranging from NBS Clauses to 2D and 3D CAD drawings.

For more information regarding the Newton Waterproofing Index, our Solution Sheets, or to find a specification suitable for your project, please fill out the form below or email our Technical Team at tech@newtonwaterproofing.co.uk

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Our staff are able to provide guidance for projects of all sizes, whether you require some general advice about damp or waterproofing, or support with technical drawings and specifications.

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