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“Construction chemicals have provided us with excellent service and high quality products at a very competitive price over the years. We would highly recommend them.”

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Tanking Slurry - 25kg

Over 3 million kilograms sold in the last ten years with zero failures, without doubt the best Tanking Slurry in the UK.

Ready-to-use cellar waterproofing & dampproofing product: just add water & mix. Made in the UK.

A single coat covers 12 square metres.

2 coats recommended for below-ground applications.

Our price: 44.10
Excluding VAT
52.92 Inc. VAT


Delivery: FREE

Construction Chemicals Tanking Slurry

Construction Chemicals Tanking Slurry is THE industry-leading product for dealing with below-ground damp and moisture. We have sold over 3 million kilos without a failure. We put this down to the fact that, as manufacturers, we have total control of the raw materials we use and our manufacturing process. Many of our competitors source their tanking slurries from third parties abroad and cannot stand by their products as confidently as we can.

No other tanking slurry on the market is as successful or as dependable as ours.

Here are some of the features that you won’t find in other products:
• Our formulation contains hydrophobic polymers to give excellent water resistance, flexibility and adhesion. 
• Incorporating glass fibres helps to prevent shrinkage and improve flexibility.
• The special cements we use have shrinkage compensation and also help to achieve a consistent setting time. 
• Ground salts in existing buildings can cause problems however by including microsilica we have reduced these effects and also achieved a dense, close-packed product.

Using Construction Chemicals Tanking Slurry to convert a damp cellar into usable accommodation is a consideration many people have taken when the cost of property has been increasing and during the current difficult market. We believe that by using our product the householder can have every confidence that they will achieve their aim and add value to their home.

If you are considering carrying out below ground waterproofing we can also help by writing a dedicated specification. Providing we have information on the current state of the project we can write the specification, detail the quantity of products required and give a cost for the materials. Feel free to call us on 0116 2301955.


Further Information

Construction Chemicals Tanking Slurry is a sophisticated cementitious formulation designed for use in below and above ground waterproofing situations. The product is made up of many components, which give high water resistance, flexibility, salt resistance, good adhesion and set control in a form that only requires water for mixing.

Unlike other Tanking Slurries seen on the Internet this product does not need the addition of an SBR Bonding Agent Our Tanking Slurry has a pre-mixed polymer therefore eliminating the need, and extra expense, of adding polymer (SBR) to ensure optimum performance.



  • High Water Resistance: This is achieved by using a highly hydrophobic dispersible polymer that reacts with the other components to give water resistance and flexibility. The grading of the powders in the slurry means that a very dense coating is produced. Particle sizes as low as 0.5 micron ensure that every potential air space is filled with an impervious sphere of water and chemical resistant material.
  • Flexibility: The polymer used is flexible and to improve this performance special fibres are added which allow a much higher level of flexibility.
  • Salt Resistance: The presence of salts in below ground situations can cause expansion when drying and lead to de-lamination at worst and efflorescence. Two components contained in the product actually react with these soluble salts turning them into solids that do not exhibit efflorescent or hygroscopic effects.
  • Excellent Adhesion: Adhesion comes from the polymer and the presence of special cements, which bind the slurry cohesively and give good adhesion to masonry.
  • Set Control: This is achieved by using rapid setting cements together with set accelerators. This ensures that even in areas where there may be water movement the slurry sets quickly whilst allowing a reasonable period for application. Where running water is experienced however, CC water seal must be used to control water flow whilst the slurry is curing. Construction Chemicals Tanking Slurry is manufactured to have to a high level of performance in any situation where lateral or penetrating dampness is found. It has been carefully formulated to ensure that it is not affected by the problems normally associated with water movement such as salt damage and movement.
  • Durable Protection: Waterproof coating has long-life characteristics.
  • Water Based: Safe to apply on damp surfaces.
  • Easy Application: May be applied by brush or spray.
  • Tried and tested over many years with no failures
  • Tanking Slurry forms part of the original substrate
  • High quality polymers give flexibility, salt resistance and good adhesion
  • Unlike some products all the ingredients for this product to work are in the bag, the operator only requires water for mixing
  • High alumina cement gives good salt resistance


Tanking Slurry is used as a waterproofing membrane, which may be applied by brush or spray. Where external ground level is above internal floor level it is usually necessary to provide a barrier to penetrating moisture in conjunction with an injected DPC. In such circumstances Tanking Slurry may be applied directly onto the brickwork before DPC injection takes place. In cellars and other areas of high hydrostatic pressure and where there could be sulphate salts present, it is advisable to use a sulphate resistant (tight) backing coat before applying tanking slurry.

Areas of use include the following:

  • Cellars/Basements
  • Tanks & Ducts
  • Underground Car Parks
  • Swimming Pools
  • Potable water tanks
  • Bund Walls
  • Foundation Slabs
  • Silage Pits
  • Party Walls
  • As a vertical DPC in stone walls or walls over 250mm
  • Fish Ponds 
  • Lift Shafts


Tanking slurry is a blend of Portland cements, quality graded aggregates and chemical modifiers, which provide a waterproof coating system. The standard product is supplied in grey, other colours can be made on request. It also contains an acrylic polymer to assist bonding therefore reducing the use of SBR directly into the slurry. Tanking Slurry is not sulphate resistant.



All contact surfaces must be clean and sound. Remove all loose materiel, laitence, dust and any previous coating. Tap off water pressure where necessary and cut out a 20mm x 20mm fillet at floor and wall joint (see page 4 individual specification). Repair any existing cracks and fractures with Construction Chemicals Rapid Cement.


The water requirement to produce the coating is 7.5 to 8.5 litres of water per 25kg of dry material. Pour the required quantity of water into suitable mixing vessel. Slowly add the powder to the water whilst continuously mixing. Mechanical mixing is recommended using a slow speed high torque drill with a plastering paddle. Mixing should be continued for three minutes after all the powder has been added to the mixing water to obtain a “creamy” consistency.


Construction Chemicals Tanking Slurry is applied in two coats (except above ground, see individual specification) the first coat in a horizontal direction down to fillet level. Apply second coat at right angles to the first as this will ensure complete coverage of the substrate. Second coat can be applied before the first is dry providing the first does not drag. In some cases a tight coat of render made up of 3:1 sand cement mix,using a sulphate resistant cement and SBR mixed at 2:1 with water as the gauging water may be required,refer to your individual specification or our technical department if you are unsure.

N.B: Do not re-temper stiffened material. Tanking Slurry should not be applied in frost conditions or to frost-filled surfaces or when temperature is 5 deg C and falling. 


The coverage will depend on the substrate surface.
Coarse surface – 2kg to 3kg per square mtr per coat
Smooth surface - 2kg to 2.5kg per square mtr per coat


In warm or windy conditions mist spraying may be used to compensate for moisture loss. In tanking applications a through flow of air is required to prevent condensation. Tanking Slurry may be rendered after 24 hours and will become fully effective after 8 days. Render coat should contain SBR to assist bonding and floor coatings should be screeded or sealed with an abrasion resistant coating. Protect from frost, direct sunlight, and drying winds for 24 hours.

Typical Properties at 20 Degrees Celsius

Water addition: 7.9 lt per 25kg unit.
Coverage – yield: 2kg per square metre per coat depending on the substrate
8.3 to 12.5 square metre per 25kg unit depending on substrate
Initial set: 30 minutes

Health and Safety

Tanking Slurry is alkaline when mixed with water and should not come into contact with skin or eyes. Avoid inhalation of dust during mixing and wear safety glasses, dust mask and cloves. If skin contact occurs wash with clean water. Should eye contact occur rinse immediately with plenty of clean water and seek medical advice. For full health and safety data refer to the Product Safety Data Sheet that comes with the product.


Tanking Slurry is not a fire risk.


Storage & Shelf Life

Tanking Slurry will have a shelf life of six months in bags. Store in dry conditions at temperatures above 5 degrees Celsius.


Delivery Information

We offer free UK mainland delivery. If you are not on the mainland, please give us a call on (0116) 230 1955 and we can give you an accurate delivery price. We make deliveries to Europe and to the rest of the world.

Please call us on (0116) 230 1955 to discuss an accurate shipping price. In certain cases, deliveries to the Highlands of Scotland & Northern Ireland may incur extra shipping costs. If such a situation arises, we will call you as we process the order in order to discuss this.


Hopefully you won't need to return an item, however, if you do, it is our aim to make this as simple as possible. By following the guidance below you can help us to help you when a product is not what you expected, or is faulty. Your statutory rights are not affected by this guidance.

If you have any questions please call our customer service team on 0116 230 1955 or email us at


How to Get Items Ready for Return

Under our 30 Day Returns policy you can return faulty or unwanted goods.

Items should be unused, in a saleable condition, in original packaging and with all component parts and any promotional items received. You should include your invoice.

Faulty Goods

In the unlikely event that goods are faulty then we will replace them free of charge.

Unwanted Goods

Unwanted goods can be returned at the cost of the purchaser & will incur a 20% restocking charge. 

Certain items are excluded from the guarantee. These include goods that are made to order,or mixed to your requirements. Other excluded items are macerators and water pumps as well as parts of larger kits.


How to Return an Item

There are four common ways to return an item:

  1. For items under 1m in length & 2kg in weight, send them back from your local post office 
  2. For larger items, call our customer service team on 0116 2301955 for further advice
  3. We also offer a carrier pick up service, however, depending on the circumstances, this may incur a charge. For more information call our customer service team on 0116 230 1955
  4. For products delivered directly from our suppliers, please call our customer service team on 0116 2301955


Time After Purchase

If you purchased the item less than 30 days ago you can return it under our 30 Day Returns policy

If you purchased the item more than 30 days ago our aim is to get the problem put right as quickly as possible. In most instances we will either offer a replacement item with the same or an equivalent product.


If the item has already been installed, call us on 0116 230 1955 for further advice.

Expert Support

It can be difficult getting it right for your project & so we'd like to offer two ways of helping. The first is telephone support, the second is project specification for contractors.

Telephone Support

We aim to win with customer support. We have experts you can ask & we want your custom. Please call us on:

0116 230 1955

Monday to Friday 9am - 5pm

Free Product Specification Service for Contractors

In order to assist our customers with their projects, we are happy to offer a free Project Specification Service to ensure that contracts and work are specified correctly  and the list of materials required is as accurate as possible. Our Technical Team has many years experience in Dampproofing, Tanking and Waterproofing situations both here and abroad.

We recognize that our customers are involved in large & complicated projects, our aim to offer a service to help them get it right.

The benefits of the project specification service are:

  • Appraisal of the requirements of your project from an expert
  • One to one Conversation with the Technical Team, if required
  • A free specification for project planning purposes
  • A site visit if required
  • A Professional Indemnity Insurance-backed specification for peace of mind

Please call us on:

0116 230 1955

or email us at

no1 We Have Our Own In-house Chemist

This gives our customers access to first-class technical advice just by picking up the 'phone or emailing. We offer an unrivalled technical service that aims to give our customers the information they need to carry out their work with the right materials. This gives them and their customers confidence.

no2 We Have Local, UK-wide Coverage

We have 3 depots covering the whole of the UK. This benefits our customers because they can arrange for local pick-ups, they get faster, more flexible deliveries, & we have large stocks readily available.

no3 We Have Our Own Transport Network

For a great many of our products, we offer a personal delivery service, giving faster delivery, more security & less frustration.

no4 We Manufacture Our Own Products

We have control over our products and manufacture to a consistent specification. This means that our customers can expect the same high-quality materials, time and again.

no5 Our Directors Have Over 100 Years of Experience in the Industry

This provides our customers with first-class technical advice & a first-rate service & a team that understands your needs & your working environment.

no6 We Have an Experienced Team of Office Staff

All of our staff have worked for us for many years & know their products & have technical expertise. The quality of support is far superior to DIY chains and to our online competitors.

no7 All Non-Construction Chemicals Products are Sourced from ISO 9000 Companies

This means that all goods for sale from Construction Chemicals are of the highest quality. We only work with companies that have a proven track record.

no8 We Have a Large, Experienced Sales & Technical Support Team

Our sales & technical support staff cover the whole of the UK enabling you to get the materials you want for the job you need to complete, when you want to.

no9 We Offer Multiple Credit Options

We offer full credit, credit card & PayPal facilities making it easier for customers to buy and for trade customers to keep an account.

no10 We Stand by the Quality of Our Products & Our Relationship With Our Customers.

If a customer is not happy with their products, we will replace them without question.

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Builders Buckets - Pack of 4

Need Technical Support? Ask Jim

Jim has decades of experience with all our adhesives, tanking products, dampproofing, timber treatment & general building chemicals. If you have a problem with application, specification or getting the right product for joinery, shopfitting or construction please call Jim on 0116 230 1955 or mobile 07768 365255

ask now