What is Liquid Waterproofing?

Liquid waterproofing is a method of protecting surfaces from water infiltration using a liquid-based coating instead of sheets. This coating dries very quickly to form a flexible, seamless, and durable barrier that fixes leaks while providing future protection against water infiltration.

SEMCO Works Liquid Membrane can be applied to a variety of surfaces including wood, tiles, concrete, plaster and more. It’s becoming the preferred method of waterproofing due to its user-friendly application and high performance.

Liquid waterproofing is commonly applied to protect balconies, terraces, roofs and other outdoor areas from water infiltration — as well as to waterproof pools, showers, flooring and other surfaces in new builds or renovations.

Liquid Membrane™ Application

Liquid Membrane™ is applied in just 2-3 coats and takes between 45 minutes and 2 hours to dry, depending on the temperature. You can use a roller, brush, or sprayer to apply it yourself.

The application process will differ for certain substrates, so read our detailed waterproofing application guides for each substrate.

Preparation

Preparation should always involve sweeping debris off the surface, to ensure the membrane bonds properly to the substrate.

For certain applications, such as all concrete and pools, you’re required to use some of our SEMCO surface cleaners to properly prepare your substrate for the waterproofing membrane.

This information can all be found in our application guides.

Waterproofing with a brush or roller

Liquid Membrane can be applied by homeowners without any trades experience thanks to its user-friendly application with a brush or roller. The application is similar to paint, and you can apply it directly onto a wide range of substrates: including wood, tiles, concrete, plasterboard, metal, and more.

Using a brush or a 12mm nap roller, apply a generous coat of SEMCO Liquid Membrane™ to your surface. Once you can walk on the surface and not get any residue on your shoe or feet, or cannot leave a fingerprint impression, it’s ready to re-coat. Make sure you apply the next thin coat of SEMCO Liquid Membrane™ in an alternate direction over the first coat.

This two coat system is perfect for floors, walls, and joinery. For submerged surfaces, a third coat of Liquid Membrane™ is required.

Apply with a sprayer

Reserved for exceptionally large areas, spray application follows the same system as a roller or brush, but with a few requirements for the sprayer.

The sprayer being used for the application of SEMCO Liquid Membrane™ should be capable of producing a minimum of 2,500 psi (17.2), maximum of 3,300 psi (22.8 MPa) with a flow rate of 0.95 to 1.6 GPM (3.6 to 6.0 LPM) using a 0.521 or a 0.631 reversible tip.

Keep the unit filled with SEMCO Liquid Membrane™ to ensure continuous application of liquid. The hose length should not exceed 30m in length and 9mm in diameter.

How long does Liquid Membrane take to dry?

It should take approximately 1–2 hours at 21°C for Liquid Membrane to dry to the touch.

Curing time depends on temperature, humidity and airflow, however typically initial cure is within 6 - 7 days as per specific product recommendations.

If coats have been applied too thick, the surface might feel tacky. This is a sign of trapped moisture. If you have left over product, apply a very thin coat over the entire surface. The surface needs to be fully cured and hard before permitting water.

Application notes

• For optimal bonding we highly recommend sweeping the surface before applying the membrane.
• Stir up the product well before use in order to mix up the colour pigments.
• Avoid application in direct sun light in the afternoon or temperatures of over 30°C as it might cause the product to dry too fast before it can adhere to the substrate
• To make your new Liquid Membrane surface trafficable, it must be sealed with our SEMCO Titan Shield Gloss sealer.
• It can not be applied to wet substrates or substrates still containing moisture, or else it will not cure correctly and stay tacky. Max. rest moisture in substrate can be up to 3%. If you are unsure about the moisture content, have it measured prior to application.
• For applications where the product is fully submerged, 3 coats at 1mm each is required. Application must coat the entire surface to above the waterline.
• For applications where SEMCO Liquid Membrane™ is applied on pool plaster, extended curing times might occur as plaster holds more moisture which needs to breathe out first. A slight colour change may occur when being in contact with water when the product has not fully cured yet. This however will not affect the performance of the SEMCO Liquid Membrane™.
• It is always advisable to apply a small test patch in an inconspicuous are to ensure adequate adhesion prior to full application.