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How to Apply Liquid Roof to Your Caravan

Imagine the damage water ingress will cause to your caravan if you don’t repair it. Liquid Roof liquid EPDM makes it easy to apply a long-lasting, self-smoothing, great-looking coating to any caravan roof – whether you’re a DIYer or professional caravan repairer. This page gives you guidance on applying Liquid Roof, the only true EPDM liquid available in the UK. But if you just 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

How much Liquid Roof do I need?

Liquid Roof normally covers 3.70 to 3.90 m2 (40–42 ft2) per 3.78 L (1 US gallon), but up to 4.2 m2 (46 ft2) per 3.78 L (1 US gallon) on very smooth surfaces. You will achieve the required 0.5 mm (0.02 in.) film thickness when you use this spreading rate.

For advice or help with calculating how much Liquid Roof you will need, please call 0800 6120 750 or email us

US Gallons Litres Coverage (m2) Coverage (ft2)
 1/4 950ml 0.925–0.975
 1 3.78 3.70–3.90  40–42 
 2 7.56 7.43–7.80 
 3 11.34  11.14–11.70 
 4 15.12 14.86–15.60 
 5 18.90  14.86–15.60 
 6 22.68  22.29–23.41

Preparing the surface of your caravan roof

Liquid Roof is easy to use, but as with any product, surface preparation is key to a good finish. The roof of your vehicle must be structurally sound, clean and dry. You’ll also need to survey any damage, paying careful attention to three areas:

  • Repair any gaps, holes or tears
  • Remove any rust with a wire brush
  • Remove any Silicone: Liquid Roof won’t adhere to silicone surfaces

The surface to be coated should be clean, dry and structurally sound. Fasten loose areas with adhesive (contact cement) or pop rivets. Remove oil or wax completely with solvent. Remove brittle caulk and loose portions of existing coatings with a scraper and/or wire brush (anything adhering well may be recoated). Wire brush rusty or pitted metal to remove any loose oxide (you may coat tightly-adhering corrosion directly with Liquid Roof).

Remove as much as possible of any asphalt-based aluminum coatings with a wire brush or abrasive disc. Remove roof cements and replace them with butyl caulk where necessary. Repair torn rubber with adhesive butyl tape. You may apply a rubber patch over torn areas if desired. Remove chalk from white rubber membrane by brushing with detergent solution followed by a water rinse or working the surface with a stiff brush. Smooth metal or plastic surfaces should be roughened to improve adhesion of Liquid Roof. A de-glossing solvent may work on some plastics.

Got a question about surface preparation? Please call 0800 6120 750 or email us

Mixing Liquid Roof

Proper incorporation and thorough mixing of the catalyst is critical to achieving desired cured film properties and must be done with great care. The container is underfilled to allow for the addition of the pre-measured catalyst 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 and 18.90 L (4 or 5 US gallon) pails you MUST use a long shaft mixer.

DO NOT pour the catalyst onto the Liquid Roof prior to starting to mix. Mix the rubber material in the container for about a minute until the material is moving uniformly; then centre the mixer shaft in the pail or can and begin mixing until a vortex is formed. Now slowly pour all of the catalyst into the vortex at a rate that allows it to be incorporated without puddling. After all the catalyst has been added, move the mixer up and down and in a circular motion for 2–3 minutes until all portions of the can/pail are uniformly mixed. Periodically scrape the sides with a rubber or metal spatula to incorporate the stagnant layer of material adhering to the walls of the pail.

Got a question about mixing Liquid Roof? Please call 0800 6120 750 or email us

Applying Liquid Roof

Apply Liquid Roof by brush, roller or squeegee (a combination of methods may be most effective). For example, on a flat roof, pour a serpentine bead of material, distribute it with the squeegee, then finish with a short-nap roller to press air out of cracks and even out the wet film. The coating will self level when sufficient material has been applied. Working time is 4-6 hours depending on temperature. A single application of Liquid Roof is preferable to multiple coats. Apply by brush around flashings and edges using long, slow strokes. On flat surfaces, material can be poured, spread with a squeegee and then evened out with a short nap roller. Apply touch-ups as desired after the initial film has cured and the surface has first been wiped with solvent.

Got a question about applying Liquid Roof? Please call 0800 6120 750 or email us

Temperature and Cure Conditions

Liquid Roof may be applied at any temperature that permits it being spread on the surface. In order to cure, Liquid Roof must be exposed to air. Because it is a hydrophobic material, it is completely waterproof immediately after application and can withstand rain showers or pooling water before it has cured. Please note that this will halt the curing process until the part of the surface that is underwater is exposed to air again. The cure rate for Liquid Roof is accelerated by sunlight or higher temperatures and slowed by cooler temperatures. Exposure to freezing before curing has taken place will not damage the film. The time necessary to reach cure should not be a concern, as this process will occur automatically. Between 12 °C and 26 °C (54 °F and 79 °F), the coating should be touch dry overnight and completely cured after about a week. (If you get a cold spell and the cure takes longer, it will still achieve the same result and have the same properties.) Liquid Roof will provide long term protection even under extreme exposure conditions.

Got a question about temperature, curing, or any other aspect of applying Liquid Roof? Please call 0800 6120 750 or email us

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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