Waterproofing Concrete with Slurry

Waterproof coatings are used to make floors and walls resistant against water. They are used for many applications where water resistance of building components is important.

The coatings we accept need to be suitable for standing seepage water and water under pressure. A water level of several meters on top of the waterproofed surface should be acceptable. The coating should be suitable for water tanks, swimming pools and large aquariums.

Waterproofing Slurry

"Waterproofing slurry" - as we define it - are waterproof concrete coatings used in combination with tiles. This material is sometimes also called waterproofing membrane

• Schomburg Aquafin RS-300: We use this ourselves. Here is an application video (German Language). The test certificate for RS300 allows 6m water pressure and uses a safety factor of 2.5. Aquafin RS300 therefore has actually be tested on 15m.
• PCI Bauchemie Seccoral 2K Rapid: a so called safety waterproofing slurry. According to PCI it can be used in swimming pools in water depth of up to 6m.
• PCI Bauchemie Dichtschlämme: This is a one component based mineral slurry. According to PCI it can be used for swimming pools. At Hydrosight we prefer two component slurries.
• Botament RD2. One of our customers uses it in Ireland - we have no experience with it.
• Winkler Chimica : A product from Italy that is supposed to work well.
• Otto-Chemie Dichtschlämme : A one component slurry. Suitable for swimming pools up to 4m waterdepth (Source: Otto-Chemie).
• Flexcrete Waterproofing System is a cement based flexible waterproofing, 2 components (?) and popular in the United States.
• Westwood, a company from Switzerland, provides Wecryl 235. It is applied before tiling. It based on PMMA, which is different to most of the other products. This product is NOT advertised for standing water, thus not acceptable.
• BASF MasterTile WP 666, a product, that is popular in Turkey, seems to fulfill the requirements

These products are NOT recommended:

• Mapei Mapelastic: 2 component, flexible mortar; according to document sheet it can be use up to 1,5bar under water. In some countries Mapelastic is the name of a whole range of products. Make sure you choose the two component cementitious mortar. Do NOT choose Mapelastic Turbo or Mapelastic Aquadefense. Mapei recommends not to apply the mortar directly to stainless steel surfaces. Preparation of the steel surface is necessary. According to Mapei sales the steel is to be coated with a layer of epoxy. The fresh epoxy is then to be sprinkeled with silica sand (quarz sand).
• Ardex S7: 1 Component Slurry. Hydrosight does NOT recommend this type of Ardex material.
• Xypex Concrete water proofing (by crystalization)

Following material might be used without tiles:

• Sika SikaTop Seal-107: Two component semi-flexible damp- and waterproofing mortar. Has been tested and found suitable. However there seems to be no depth rating for SikaTop 107, so the material comes with a certain risk. Also it is only slightly flexible, which reduces the crack bridging abilities.
• Remmers Multi-Baudicht 2K: Remmers is a German company. Remmers offers a "primer" to be applied before the waterproofing. Our experience with 2K was positive. It is tested to be waterproof for a column of 8m water
• Vandex Cemelast (old name BB75E?), a elasticized waterproofing slurry. It is suitable for drinking water and therefore also for aquaria. Vandex is a company from Switzerland

Bituminous Coatings

• Carlisle Hot Waterproofing: This is a US supplier. It is based on bitumen or tar, which needs to be heated to become liquid.

Polyurea Coatings

Polyurea based coatings seem to become more frequent nowadays. They are used in industrial tanks and elsewhere. Polyurea based coatings might be fibre reinforced.

• Kemperol 2K-PUR, polyurea based, fibre reinforced. Not for use under permanent water pressure. Find more on www.kemper-system.com
• Rocathaan Hotspray, polyurea based, also from the Netherlands, sold by a company called Prokol.
• Meyer-Pren. Find more on meyer-bauabdichtung.de
• Sopro 2-K DichtSchlämme Flex 2-K - DSF, suitable for up to 6m below water.
• Products from the company Kerakoll: Aquastop Nanoflex could be suitable, however misses the depth rating in the technical documents. Kerakoll recommends their product Superflex Eco. Superflex Eco also misses the depth rating.
• not further tested: alchimica.com Building Chemicals - Hyperdesmo -2k-W - a product from Greece

Polyester/Fibre Coating

• Romar-Voss Vinylester. High Quality / High Price product

Two Component Epoxy Based Coatings

• Sika Sikagard 136 DW: Sikaguard is used suitable for drinking water. This also makes it suitable for aquaria, where other products might be harmful to fish and other content.

Plaster Finish

Hydrosight does not consider any plaster finish as sufficient for waterproofing. The following products belong to the category plaster finish.

• Marcite is an another term for standard (generic) plaster. It consists of white sand and cement (?). Marcite acts as both water tight barrier and coating finish. This white plaster is mainly used in North America. Typical thickness is 13mm (approx 1/2 Inch).
• Diamond Brite
• Microcement used for pools, eg Aquacrete.

It might be a good idea to additionally use a slurry like Aquafin RS300. We recommend to perform material tests before proceeding with this combination.