Applying EPDM Liquid Rubber Roofing, Rubber Gaskets and Sealants
Only true EPDM in Liquid form in the World
Phone: 01453 872850 or Email

Applying Liquid Rubber EPDM

Applying Liquid Rubber EPDM in 4 easy steps

Imagine the damage water ingress and other effects of weather will cause to your property if you don’t do maintenance and carry out repairs on time. By applying EPDM Rubber, it’s straightforward for your maintenance team or a suitably experienced independent contractor to apply a durable, high-performance coating that will protect your structure for years.

To ensure a high performance result, thorough preparation and the right techniques are vital when working with any rubber gaskets and sealants. Here’s where we show you how to apply Liquid Rubber EPDM correctly in four easy steps. Remember, this is the only true liquid EPDM rubber available in the UK. If you can’t wait to talk to us about this proven product, please contact us.

Professional advice is free. Please Call now on 0800 6120 750 or email us

STEP 1: Calculating how much Liquid Rubber you need

Normal coverage rate when applying our EPDM rubber is 3.70 to 3.90 m2 (40-42 ft2) per 3.78 litres (1 US gallon) on a typical substrate. The required 0.5 mm (0.02 in.) film thickness is achieved when this spreading rate is used. Liquid Rubber covers up to 4.2 m2 (46 ft2) per 3.78 litres (1 US gallon) on an optimal surface. If you’re not sure how to calculate how much material you’ll need,  contact us

US Gallons Litres Coverage (m2) Coverage (ft2)
 1/4 950ml 0.925–0.975 
10–10.5
 1 3.78 3.70–3.90 
40–42 
 2 7.56 7.43–7.80 
40–42 
 3 11.34  11.14–11.70 
120–126
 4 15.12 14.86–15.60 
160–168
 5 18.90  14.86–15.60 
200–210 
 6 22.68  22.29–23.41 
240–252 

STEP 2: Preparing the surface

For more information about the surfaces you can and cannot coat with Liquid Rubber, please visit our Suitable Surfaces page.

As with all rubber sealants, preparation is key to achieving a good finish. The surface to be coated should be clean, dry and structurally sound. You must also repair any gaps, holes or tears (you can use a rubber patch over torn areas) and fasten loose areas with adhesive (contact cement) or pop rivets.

  • Before applying EPDM rubber, remove any residual Silicone.
  • Wire brush any rusty or pitted metal to remove loose rust. Tightly adhering corrosion may be directly coated with Liquid Rubber.
  • Completely remove any residues of oil or wax with solvent.
  • Remove brittle caulk and loose portions of existing coatings with a scraper and/or a wire brush.
  • Asphalt based aluminium coatings should be removed as much as possible by wire brush or abrasive disc.
  • Remove and replace roof cements with butyl caulk where necessary.
  • Remove chalk from white-rubber membrane by brushing with a detergent solution followed by a water rinse or working the surface with a stiff brush.

You can leave any residual material that has good adhesion for recoating.

To improve the adhesion of EPDM rubber, lightly sand the roof and any smooth metal or plastic fixings and surfaces you will be coating. A de-glossing solvent may work on some plastics.


STEP 3: Mixing Liquid Roof

IMPORTANT: Do NOT add the catalyst to the Liquid Rubber immediately.

The container is deliberately underfilled to allow for addition of the pre-measured catalyst that’s included in your kit. You will need a drill and a mixer to incorporate the catalyst. For 950 ml (1 US quart) and 3.78 L (1 US gallon) cans, a short mixer will suffice. For 15.12 L (4 US gallon) and 18.90 L (5 US gallon) cams, you MUST use a long-shaft mixer.

First, mix the rubber material in the container until it is uniform. Next, centre the mixer shaft in the can and begin mixing until a vortex forms. Now, slowly pour all of the catalyst into the vortex. Move the mixer up and down and in a circular motion for 2–3 minutes until all the material in the can is uniformly mixed.


STEP 4: Application - just think of it as Liquid Rubber paint

To see how to spray liquid rubber onto a surface, please visit our Spray Liquid Rubber page.

A single application of Liquid Roof is preferable to multiple coats. Liquid Rubber can be applied at any temperature that allows it to be spread on the surface. 

Apply Liquid Rubber with a brush, roller or squeegee – a combination of methods may be most effective. Around flashings and edges, use a brush to apply the material in long, slow strokes. On flat or large surfaces, pour a serpentine bead of Liquid Rubber, distribute with a squeegee and finish with a short-nap roller to press air out of cracks and even out the wet film.

When applying EPDM rubber, the coating will self-level when sufficient material has been applied. Working time is 4–6 hours, depending on temperature. Touch-ups may be applied as desired after the initial film has cured and the surface has first been wiped with solvent.


Temperature and Curing Conditions

Liquid Rubber requires exposure to air to cure, however it is immediately waterproof and can withstand rain showers or pooling water before it has cured. If water gathers on the surface before it cures, the curing process will be temporarily halted until the surface is exposed to air again.

At temperatures between 12 and 26 °C (54 and 79 °F), the coating will cure completely within a week. When applying EPDM rubber, the curing process is not affected by humidity but is accelerated by sunlight and hotter temperatures, and slowed by cooler temperatures. Exposure to freezing temperatures before curing has taken place will not damage the film.

The final film properties of the cured membrane will be the same regardless of how long it took to cure. Our Liquid Rubber roofing coating will provide long-term protection even under extreme exposure conditions.


WARNING: Please read container for complete safety precautions and instructions. Heed all warnings. Please read all directions completely before beginning the application process. Please make sure all safety precautions are followed and appropriate safety equipment is used

The information presented herein is furnished free of charge and is based on technical data that we believe to be reliable. It is intended for use by persons having technical skill and is at their own discretion and risk. Since conditions of use are outside our control we make no warranties, express or implied, and assume no liability in connection with any use of this information. Nothing herein is to be taken as a license to operate or a recommendation to infringe any patents.

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