Description

Mud Brick Water Repellent (MBWR) is a solvent-based silane/siloxane impregnant for mud brick or other earth buildings. The product is designed to penetrate into the capillaries of substrate surfaces and render the substrate water repellent. This water repellent zone reduces the absorption of water or efflorescence or other water-borne staining materials which are responsible for the bulk of the deterioration in earth building materials. The treatment will not significantly change the appearance of the substrates and the vapour permeability. However, a slight darkening of the surface may occur for some substrates.

Recommended Uses

MBWR is recommended as a water repellent sealer for mud brick or other earth buildings. It is also suitable for other substrates including stabilised earth/rammed earth, natural stones, concrete masonry, bricks, and tiles & grout.

Key Features

• Penetrates into substrate surface.
• Permanently bonds to the substrate with no peel or blister.
• UV, alkali stable and durable formulation.
• Reduces water penetration, efflorescence and water-borne staining.
• Does not significantly change the surface appearance and vapour permeability.
• Easy application and cost effective.

Use Instructions

Application

Please read the product information for the correct application and safe handling. A test prior to application is strongly recommended to determine of the number of coats required and suitable consumption rate.

• Avoid applying the product during rain or extreme weather.
• Ensure the surface is dry, firm, and free from grime, oil, or previous coatings/sealers.
• Wash the surface with a suitable detergent solution if needed and allow it to dry.
• Fill all cracks with appropriate grouting materials and allow them to cure.

MBWR can be applied with a brush, roller, or spray, but saturation flooding with a hand‑pressure or airless spray is preferred to avoid direct contact between tools and earth building surfaces. Apply enough material to ensure adequate penetration.

Vertical Surfaces

• Apply a thin liquid film that runs 30–40 cm down the surface.
• Apply a second coat immediately once the first is absorbed (“wet‑in‑wet”).
• Saturate the surface to maximise penetration.

Horizontal Surfaces

• Flood the surface for about 10 minutes to allow penetration.
• Apply a second coat immediately if the substrate absorbs the first quickly.
• Remove any unabsorbed liquid after 10 minutes to prevent uneven finish.

The number of applications depends on the permeability of the substrate. Generally, for very dense surfaces one application is enough but for permeable substrates, two or more coats “wet-in-wet” may be required.

Do not splash or spray the product onto any area you do not wish to treat.  If splashing occurs the product should be removed with a cloth damped in a solvent such as mineral turpentine immediately.

Consumption Rate

The consumption of MBWR varies significantly depending on the permeability of the substrate.  It may be of the order of 1-10 m² per litre per coat or could be out of this range significantly.

After Application

The initial surface water repellency will develop after the surface is dry.  Full curing may take 24 hours or up to 7 days.  Avoid heavy traffic or any staining for at least 24 hours.  The equipment can be washed in a solvent such as mineral turpentine.

Pilot Testing and Quality Control

Due to the variation of building materials, it is strongly recommended that a pilot test on a small area on site should be conducted prior to application to find out the suitability of this product for the purpose.

Typical Data

• Appearance: Colourless liquid with hydrocarbon solvent odour
• Solids content:<50% by weight
• Specific Gravity:0.79g/ml at 20 ºC
• pH value:Not allocated
• Solubility in water: Insoluble in water
• VOC content: >50%
• Flash point:>61°C

Important Note

MBWR penetrates the capillaries and makes the surface water‑repellent while still leaving most capillaries open so water vapour can pass through. It reduces water absorption by capillary action. However, it provides only limited resistance to water penetration, especially during prolonged contact or under hydrostatic pressure. In highly permeable substrates or during extreme wind‑driven rain, it may not provide adequate resistance to water penetration or water‑borne staining.

Handling & Storage

MBWR poses a hazardous and combustible risk. Refer to the material safety data sheet for safe handling instructions. Follow good industrial hygiene practices when using this product. Avoid inhaling vapour and prevent skin or eye contact by wearing appropriate protective equipment. Wear an air‑purifying respirator if you may be exposed to high vapour concentrations. Wash your hands after handling the product. Store the product in closed containers in a cool, dry place away from fire or ignition sources. MBWR maintains a 12‑month shelf life when kept in its sealed, original container below 25ºC.

Use with sufficient ventilation away from any fire or ignition sources

Keep out of reach of children

Packaging

Available in 5, 20 and 200 litre metal drums.