Drybase BBA Tanking Slurry


Ensure superior waterproofing with Drybase BBA Tanking Slurry. This BBA-approved, cementitious surface waterproofer can be used on a wide range of surfaces and stands up to water pressure up to 7 bar. It allows natural moisture transfer, dries efflorescence-free, and can be applied easily. An excellent choice for both horizontal and vertical surfaces.

  • Above and below ground waterproofing
  • Efflorescence-free
  • Can be spray applied
  • Tested for resistance up to a 6 m head of water
  • Resists water pressure on concrete and masonry surfaces
  • For use both above and below ground
  • CE-marked and BBA-approved

2 in stock (can be backordered)

Drybase BBA Tanking Slurry 25KG - Toner Dampproofing Supplies Ltd
Drybase BBA Tanking Slurry 74.99
Only 2 items left in stock!

We Deliver Across Ireland & UK

  • 14-Day Returns
  • Place Your Order by 1:00pm for next day dispatch
Shop with Confidence

Drybase BBA Tanking Slurry: Superior Waterproofing Solution

If you need a high-performance tanking slurry that’s able to resist the toughest of conditions, Drybase BBA Tanking Slurry is an excellent choice. This cementitious, pre-bagged BBA-approved waterproofer can be used on both horizontal and vertical surfaces, providing long-lasting protection in all seasons and conditions. It’s been tested to resist water pressure up to 7 bar (approx. 70m head) making it an ideal choice for a wide range of surfaces and structures.

Key Features

  • BBA Approved: Drybase Tanking Slurry has been certified and approved by the British Board of Agrément (BBA), ensuring its high quality and performance.
  • Versatile: From water retaining structures like swimming pools to below-ground structures like basements and car parks, and even simple damp-proofing above ground, Drybase BBA Tanking Slurry is an effective multi-surface waterproofer.
  • Vapour Permeable: It prevents water penetration while allowing the natural transfer of moisture vapour, providing an effective moisture barrier without trapping condensation.
  • Efflorescence-Free: Dries efflorescence-free, making it ideal for use around steel to prevent rebar corrosion.
  • Easy to Apply: Can be applied by brush, trowel, or render spray machine, offering flexibility and ease of use.

Strong Bond

Drybase BBA Tanking Slurry can be used on clean, flush-pointed brickwork, rendered walls, and open-pore concrete substrates. Once applied, it forms a tough coating for stronger adhesion to Drybase Universal Mortar and other concrete or masonry substrates.

Whether you’re handling small or big jobs, the exceptional bonding capability of Drybase Tanking Slurry makes it a great choice for both vertical and horizontal surfaces. Drybase Universal Mortar may be used to repair any damage prior to application, while water leaks may be filled with Drybase Waterproof Plug.


It’s perfect for a variety of applications, including basement and cellar waterproofing, underground car parks, retaining walls, lift pits, fish ponds, water features, and above-ground walls.

Additional information

Weight 25 kg
Dimensions 57 × 37 × 17 cm



Does not apply

Part Number




Effective Treatment

Damp Proofing, Waterproofing

Size(s) & Packaging

25 kg PE-lined paper bag


BBA, EN 1504-3:2005/ZA.1a


Grey Powder


Dry conditions at 5 °C to 35 °C.

Shelf Life

12 months


approx. 2.0 kg/l

Working time

approx. 45 min

Setting time

Approx. 5 – 6 h

Compressive strength

approx. 40 MPa

Bending tensile strength

Approx. 6 MPa

Chloride ion content

≤ 0.05 %

Adhesive bond

≥ 2.0 MPa

Coverage Calculator


Application for Drybase BBA Tanking Slurry:

Preparation: Concrete Substrates

The substrate to be treated must be sound and even, open pored, roughened and its surface free from voids, large cracks or ridges. Any adhesion reducing substances like bitumen, oil, grease, remains of paint or laitance must be removed by suitable means, such as sandblasting, scabbling etc. Construction joints and shrinkage cracks exceeding

0.3 mm should be routed out to a minimum depth of 20 mm. Shutter tie holes should be roughened. Water leaks must be stopped using Drybase® Waterproof Plug. Thoroughly moisten the substrate. It must be damp but not wet at the time of application. Any surface water on horizontal surfaces must be removed.

Preparation: Brick and Block-work Substrates

Any remaining plaster, render or other substances that could inhibit bonding must be removed back to the substrate. Gypsum, remains of wood or other foreign material should be removed by appropriate means. Loose mortar must be routed out and the substrate cleaned thoroughly.

Unless the substrate is particularly sound the application of
a render is recommended prior to application of Drybase Tanking Slurry. Onto the pre-wetted walls (to control suction) apply nominal 10 mm thick 3:1 sand:cement render (sand to BS 1199, Table 1). The render should be compacted onto the wall and left with an open textured finish, such as that left by a wood float.

Make localised repairs using Drybase Universal Mortar.

Thoroughly moisten the substrate. It must be damp but not wet at the time of application. Any surface water on horizontal surfaces must be removed.


Mix 25 kg of Drybase Tanking Slurry with 4–6 litres of tap water in a clean container for at least 3 minutes to a lump-free, homogeneous consistency. Use a mechanical mixer.


Drybase Tanking Slurry is applied with brush, trowel or suitable spray equipment.

A maximum of 2 mm (approx. 4 kg/m2) can be applied in one working cycle. Normally two coats are recommended. Please refer to relevant coverage rate. It is recommended to apply the next coat whilst the previous coat is still damp on the surface. The previous coat is textured by suitable means, (such as a soft brush) whilst still plastic to form a key.

The previous coat must not be damaged during application of the following coat. The waiting time before applying the second coat is usually between 2 – 4 hours depending on climatic conditions such as humidity, temperature, etc. To maintain workability of the material do not add water, simply re-stir the mixture.

Do not apply at temperatures below +5 °C, or to a frozen substrate.

Brush application

Can be used to ‘prime’ the surface. Ensure that all cavities in the substrate are filled and appropriate cover is achieved. It should be applied to a level surface to avoid insufficient coverage.

Trowel application

First a scratch coat is applied for maximum adhesion to the substrate, working from the bottom up. Ensure all cavities in the substrate are filled, to exclude any trapped air.

Spray application

Drybase Tanking Slurry can be sprayed typically using a nozzle with a diameter of 6 mm. Apply first coat of Drybase Tanking Slurry in a circular motion with spray nozzle at a 90° angle to the substrate. The material is flattened and keyed.

The final layer can be left as a spray finish or for further advice refer to ‘Plastering/Coating’ section.


Keep damp for at least 5 days and provide protection against extreme weather conditions (e.g. sun, wind, frost). The freshly treated surfaces should be protected from rain for a minimum period of 24 hours.

Plastering and Coating

Surfaces treated with Drybase cementitious products to be coated or painted should be left to cure for 4 weeks. When
a plaster or render finish is required, it is essential to apply a rough cast of sand and cement on the Drybase cementitious coat while it is still ‘green’.

On hardened surfaces apply an appropriate bonding agent before rendering, such as Drybase SBR (not PVA) Coatings on top of a Drybase treatment have to be alkali resistant.

Decorative coatings and paints should be water vapour permeable.

Pick-up In Store


There are no reviews yet

Add a review
You must be logged in to post a review Log In

Q & A

There are no questions yet

Ask a question

Your question will be answered by a store representative or other customers.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Thank you for the question!

Your question has been received and will be answered soon. Please do not submit the same question again.



An error occurred when saving your question. Please report it to the website administrator. Additional information:

Add an answer

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Thank you for the answer!

Your answer has been received and will be published soon. Please do not submit the same answer again.



An error occurred when saving your answer. Please report it to the website administrator. Additional information: