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How much Durabak do I need for my RV?

Print Application

In order to properly seal the roof of your RV you will need at least 2 coats of Durabak 18 Smooth applied over it.

Here's a handy table to help you work out how much smooth Durabak 18 you'll need.

Motorhome Length in feet How many gallons? Link to purchase
up to 8' 1 gallon BUY
up to 16' 2 gallons BUY
up to 24' 3 gallons BUY
up to 32' 4 gallons BUY
up to 40' 5 gallons BUY
up to 48' 6 gallons BUY

 Choose a color

We recommend using polyurethane caulking to fill any holes and gaps and cracks more than a hair's breadth wide before applying the Durabak. You can also apply as many coats of Durabak as you like to seal corners and edges for a more robust and flexible seal - as soon as the last coat is touch dry you can apply another coat.



Application Guidelines for EPDM RV roof, also good for fiberglass: 

Durabak is GREAT on Rubber; it flexes, stretches and moves with it!
Applying Durabak on Rubber is simple, if you follow these instructions carefully it will never come off!


  • 2 stipple roller sleeves per gallon (Included with purchase of textured gallon) or short nap roller, like a 3/16” mohair or similar for a smooth application.
  • 40 grit Sandpaper
  • Xylene or Solvide
  • Stir stick or electric paint mixer
  • Roller Tray
  • Cloth or sturdy cotton rag
  • Paint Gloves
  • Household non-chlorinated detergent, like Spic n Span
  • 3M Blue tape (Optional)
  • Paint Respirator (Optional)
  • Primer (Optional)

Surface Prep

  • Clean the surface thoroughly, with a non-chlorinated household detergent
  • Rough up the surface with 40 grit sandpaper
  • Wipe down the surface with xylene or Solvide on a cloth and once completely dry, apply the Durabak.

Application Process

  • Do not open can until surface is prepped and ready to go.
  • Then open can and stir well.
  • Pour a portion into a roller tray and begin application.
  • Roll on first coat of textured using Durabak stipple roller sleeve, or a short nap roller for the smooth Durabak.
  • Use a paint brush in corners and hard to reach areas.
  • Stir occasionally while working with the product.
  • Keep lid on can while not in use.


1 gallon of smooth Durabak covers roughly 75-80 square feet in our standard 2 coat application.

1 gallon of textured Durabak covers approximately 60 square feet in our standard 2 coat application.

Good to Know

  • Durabak begins to cure with exposure to air, so minimize exposure to air while working with it.
  • The consistency of the Durabak should be runny, as it’s self leveling. If it’s thicker, you can add up to 15% xylene to thin it. It should be mixable after adding the xylene and back to a runny form. If it’s pasty and thick, DO NOT APPLY, rather reach out to us for assistance.
  • You will have a few hours of work time once the can is opened (3 to 5 hours normally).
  • A second coat can be applied after 1-2 hours, once the first coat is touch dry.
  • After second coat is applied allow 24 hours before walking on it. Complete cure is about 5 or 6 days, so no heavy use until then.

Additional Tips

  • Temp should ideally be 60 degrees or above for the application, and above 40% humidity.
  • Xylene should be applied immediately to clean up any misapplied Durabak.
  • If taping off, use 3M Blue tape and remove immediately after second coat is applied.