Best Caulk For RV Exterior – 2020 RV Sealant Top Picks

It is possible to build the RV exterior as heavy-duty and robust as the exterior of a tour bus. Then, we will never have to worry about waterproofing it, right? The only problem is that such an RV would probably be a bit expensive, maybe almost as expensive as a tour bus. And, we’ll have to spend more to kit out the interior and make it comfortable enough for living. Anybody (well, almost anybody) can afford an RV nowadays, but how many people do you know that own a tour bus? When you think of it this way, waterproofing the RV once in a while is no big deal at all. The first thing you need to do is find the right caulk.

Top Picks: Best Caulk For RV Exterior



Dicor 501LSW-1 Epdm Self-Leveling Lap Sealant-10.3 Oz. Tube, White, 10.3 Fluid_Ounces (Packaging May Vary)

*Our Top Pick*

Dicor 501LSW-1 Lap Sealant
  • EPDM and TPO compatible 
  • Adheres to any surface
  • Reliably secure seal

Geocel 28100V Pro Flex Crystal Clear RV Flexible Sealant - 10 oz, Quantity 1 (GC28100)

Geocel 28100V ProFlex RV
  • Crack resistant
  • Flexible
  • Easy application

Tremco Vulkem V116GRY 116 Polyurethane Sealant, 10.1 oz Caulk Tube, Gray

Tremco Vulkem 116
  • Interior & exterior use
  • Durable & flexible
  • Adheres to all common surfaces

Why can’t I just use the silicone caulk that I have lying around somewhere?

Silicone caulk is by far the most common. It’s white so we use it for the bathtub and toilet and sink and everything at home. However, it is not suitable for RVs mainly because it gets hard and too brittle. It doesn’t withstand the road very well. It’s also very hard to remove. Not only are other caulks such as polyurethane much easier to remove, but you don’t even have to remove them. You can just put additional caulk over them. But, you’ll have to remove silicone caulk because nothing sticks to it, not even silicone. As for RV exterior, we’ll show you what’s best.

Does the caulk work on every fixture and material?

The parts on an RV in need of waterproofing include the roof, windows, walls, and more. The materials include synthetic plastic, vinyl, aluminum and other metals, even wood. Caulks that are designed for RVs will work on most materials, but not all. Don’t worry, we’ll bring this info to your attention. In addition, some RV caulks are optimized for horizontal structures like the roof while others are for vertical structures like windows, and some are suitable for both.

Is it expensive and should I worry about getting the best deal?

In keeping with our premise that owning an RV is not like owning a tour bus, the best caulks for RVs are not expensive! If you get it on Amazon, you can also be sure you’re getting the best deal. However, you will need more than one tubes of caulk depending on the size of your RV and how much waterproofing is needed. How often do you need to waterproof the RV depends on how much you use the RV. Frequent travelers often inspect the RV for leaks twice a year. Needless to say, the quality of the caulk and the workmanship can also make a difference.

Our Picks for the Best RV Sealant

Dicor 501LSW-1 Lap Sealant

Dicor 501LSW-1 Epdm Self-Leveling Lap Sealant-10.3 Oz. Tube, White, 10.3 Fluid_Ounces (Packaging May Vary)
  • Creates a secure, secondary seal along the roof’s edges, air vents, vent pipes and screw heads
  • Adheres firmly to aluminum, mortar, wood, vinyl, galvanized metal, fiberglass and concrete
  • Compatible with EPDM and TPO sheeting

Dicor 501LSW-1 is by far the most popular caulk for RV exteriors. It is Amazon’s #1 best seller in industrial sealants. It is more popularly known as the Dicor lap sealant because this caulk laps around instead of hardening completely. Note that “laps around” doesn’t mean it’s runny. In fact, this is a rather thick caulk. Due to this feature, the Dicor lap sealant is best used for the RV roof, which is the biggest structure in need of sealing.

  • One of the best sealant for EPDM, a synthetic rubber. EPDM sheets are popular for RV roofs, and many caulks don’t work well on synthetic rubber.
  • Also works with aluminum, galvanized metal, vinyl, mortar, wood, and concrete.
  • Does not stain or discolor.
  • UV stabilized against deterioration from the sun.
  • Not suitable for vertical sealing.
  • Uses petroleum distillates but Dicor has done a lot of studies to prove they’re safe.

The Dicor lap sealant is the best caulk for RV roofs. After application, the caulk remains flexible. It seals continuously and does not break off. There are lots of places that need sealing on the RV roof including roof edges and vents. Get it right with the Dicor 501LSW-1 lap sealant.

Geocel 28100V ProFlex RV

Geocel 28100V Pro Flex Crystal Clear RV Flexible Sealant - 10 oz, Quantity 1 (GC28100)
  • Crack resistant
  • Exceptional flexibility
  • Excellent adhesion to many surfaces, even when damp

Geocel 28100V is another top-rated caulk for RV exteriors. It is simply known as the ProFlex. Almost everybody in the know has heard of it. ProFlex is a flexible polyurethane caulk that works on both vertical and horizontal structures. This flexibility is required to withstand the vibration and temperature changes that an RV has to undergo.

  • Flexible and crack resistant.
  • Rated for aluminum, coated steel of Kynar 500 based finishes, steel, fiberglass, glass, wood, and vinyl.
  • You don’t have to remove it since the material is resealable – just apply over the old caulk.
  • Mildew and dirt-resistant.
  • Does not work with synthetic rubber.

ProFlex comes in several finishes: clear, white, black, almond, bright white. This caulk can also be painted. It spreads and applies easily to all sorts of materials and configurations. This should be the RV caulk of your choice and the only one you’ll need if your RV does not have synthetic rubber parts.

Tremco Vulkem 116

Tremco Vulkem V116GRY 116 Polyurethane Sealant, 10.1 oz Caulk Tube, Gray
  • Date on Tube is Date Manufactured. Shelf Life is 18 Months from that Date

The Vulkem 116 by Tremco is a very affordable, yet high-performing polyurethane caulk. It is not specifically marketed for RVs but we love it for RV exteriors. It provides the tightest seal on precast concrete, masonry and other construction joints. It's also good on window frame perimeters and metals. The textured gray finish looks like an industrial power cord and gray metals, which makes this caulk non-obtrusive on an RV.

  • Very affordable.
  • Permanently flexible so great for RVs.
  • Can be stained and painted.
  • Water-repellant and mildew-resistant.
  • Not compatible with synthetic rubber.
  • Only one finish available which is gray.

The Tremco Vulkem 116 works for both vertical and horizontal joints on the RV. It works beautifully on non-smooth surfaces. It currently flies under the radar for RV use. Frankly, we love to show off the Vulkem 116 around the RV and tell people all about it. It is very useful because you can use it on other things. It is simply awesome for expansion joints and porous construction materials.


In order to survive the roads and the weather, the best caulk for RV exterior must be flexible. The most popular caulk for RV exterior by far is the Dicor lap sealant which in our opinion is the best rv sealant. We also like polyurethane caulks like the ProFlex and the Vulkem 116. The first thing to take into consideration is the material that you’ll be sealing, and then you’ll have to make sure that the caulk is suitable for vertical or horizontal application, or both. In any event, leave the silicone caulk at home and don’t use it on your RV. The best caulk for RV exterior can be applied quickly over itself.

Gary Michaels
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Last update on 2021-01-20 / Affiliate links / Images from Amazon Product Advertising API