Sealing Up Your RV for Winter Weather

Cooler temperatures and naked trees signal a sad reality for the majority of RVers: Camping season is over. Now, it’s time to get RV maintenance chores done before winter weather comes. And one of the most important maintenance jobs is sealing up your RV in preparation for winter weather. 

Moisture from rain, snow, and all of their wintry combinations is your RV’s biggest enemy. Because when moisture gets beneath the outer surfaces of your RV, it causes all kinds of problems. Things like delamination. And mold. And rot. The seals on the roof and exterior walls of your RV form part of a protective barrier. Together, they help prevents water from rain and snow from seeping into your RV. 

The brutal reality is this: How often you inspect and maintain your RV seals is a determining factor in how long your RV will last. As the old saying goes, “An ounce of prevention is worth a pound of cure.” In this case, the ounce of prevention means inspecting all of your RV seals and then resealing where necessary.

Now, here’s the good news. Sealing up your RV is not a difficult job. Plus, it’s one that could save you thousands in the long run. Seals are easy to find on the roof and all of the exterior walls of your RV, wherever two surfaces meet.  (RVs with slide outs also have slide-out seals that require regular maintenance.)

So, let’s look at the best ways to seal up your RV before winter weather hits.   

 

3 Types of RV Sealant

For this article, we’re going to focus on the three basic types of RV sealants. (Although we invite you to go even deeper into RV sealant 101.) Self-leveling lap sealant is used on horizontal surfaces on the roof of the RV.Non-sag lap sealant is used on angled surfaces, like around  the edges of the RV roof where self-leveling sealant would drip down the sides. Flexible sealant is used on the exterior  walls of the RV.  

Self-leveling and no-sag roof sealants are colored to coordinate with just about any RV roof color. Flexible sealant is also available in a few colors too. However, transparent flexible sealant is a popular choice for exterior walls. 

 

Maintaining Your Slide-Out Seals 

RV slide-out seals are black rubber gaskets that keep rain and cold air out of the RV. You’ll find them on each side of the slide-out, where it meets the RV wall. RV slide-out seals should be inspected and lubricated at least twice yearly, depending on how frequently the slide-outs are used. These seals need to be kept supple with a slide-out seal conditioner applied several times per year. If they aren’t properly maintained, slide-out seals become dry, brittle, and useless at keeping moisture out.   No matter where your RV will be spending the winter, getting this job done before the cold weather hits will help ensure it’s ready to go camping season. 

 

What You’ll Need

• A ladder
• RV slide-out seal conditioner
• A soft, absorbent cloth

 

How To Inspect and Reseal RV Slide Out Seals

1. Extend the slide-out. Set up the ladder close to the slide-out seals so you won’t need to reach.
2. Inspect each seal on the slide-out, looking for cracking, damage, or stiffness. The rubber slide-out seal should be supple enough to move back and forth with the slide-out.  Cracked or damaged slide-out seals can allow water to get in and will need to be replaced. 
3. Spray foaming slide-out seal conditioner on every surface of each of the slide-out seals.
4. Allow it to set in on each of the rubber seals for about 10 minutes.
5. Use a soft, absorbent cloth to wipe away any excess seal conditioner.

 

Protecting Your Exterior Wall 

You’ll find wall seals around windows, doors, and any area where the manufacturer cut a hole for an appliance. These  seals are there to deflect water from getting under the siding of the RV. If water does get it, it can cause the siding to come apart.  Therefore, it’s crucial to inspect this caulking every six months. You’ll need to recaulk any areas where it looks like water could get in. 

Resealing vertical RV surfaces is an easy but time-intensive job. For this reason, many RVers prefer to leave this job to professionals. However, if you have time and have a steady hand, it can be a satisfying DIY job. With that being said, here’s what you’ll need to do to ensure the seals on your RV walls are keeping moisture out of your RV.   

 

What You’ll Need 

• Ladder
• Nitrile gloves
• Plastic scraper for removing old sealant
• Flexible sealant made for RVs
• No-drip caulking gun
• Mineral spirits
• Absorbent cloth 

 

How To Inspect and Reseal RV Walls

Starting Your Inspection

1. Choose a sunny day, if you’re working outside.
2. Wash the RV.
3. Work on one wall at a time.
4. Identify all the seams on the sidewalls. Then the front cap. Then the rear wall of the RV, including windows, entry doors, and housings for lights.
5. If you have a trailer, start at the front of the RV.
6. Inspect the sealant at each seam for water intrusion points. Look for cracking, dryness, shrinkage and loose, peeling  sealant. If the sealant is in anything less than stellar condition, it’s a good idea to recaulk those areas. 
7. Inspect rubber gaskets around windows and doors for cracking and shrinkage.

 

Scraping and Cleaning

1. If your RV is caulked with Geocel Proflex (a popular sealant), it can be applied over itself. However, if it’s sealed with silicone, you’ll need to remove all of the old sealant before you can apply sealant. That’s because nothing will stick to silicone. Scraping off the old silicone sealant may be a painstaking job. Even so, it will be well worth the trouble.
2. If you need to remove old silicone sealant, it can be helpful to apply mineral spirits to the old bead before peeling it off. Also, use a plastic (never metal) scraper to get any leftover bits.
3. Get an absorbent cloth damp (not soaked) with mineral spirits. Then carefully wipe the area where you’ll apply the sealant. This helps the sealant adhere to the surface beneath it whether you’re applying it over nonsilicone sealant or an RV wall.

 

Applying the Sealant

1. Now insert the tube of sealant in your caulking gun. Then carefully cut the tip at a 22 degree angle about one-eighth of an inch from the end. The hole should be very small.
2. Squeeze the trigger a few times and wait for the sealant to appear at the end of the tube.  
3. Apply a bead of sealant to the seam, working in sections of about one to two feet at a time. 
4. When the whole seam has a bead of sealant on it, wipe your index finger on the mineral spirit dampened rag. Then gently drag it across the bead of sealant you just applied. In doing so, you are smoothing the surface and pressing the sealant into the seam. 
5. Repeat with each seam that needs resealing until all the seams on the wall are finished and protected. Admire your work for a minute or two, and then move to the next wall. Start a new inspection and repeat the steps.

 

Inspecting and Resealing Your RV Roof 

Your RV roof shelters and protects everything inside your RV. So, it makes good sense to look after it. Since even a tiny hole in your RV’s roof membrane can allow a damaging amount of moisture into the RV, it’s important to inspect it at least twice a year. When you inspect it, you’re looking for holes or tears in the roofing membrane, bubbling, and soft spots. You’ll also want to check the sealant around roof edges and extrusions for cracks, dryness and peeling. Applying roof sealant isn’t difficult. However, it’s important to use the correct product for your RV roofing membrane.  

Many RVers report success using roof repair tape to either reseal or repair their RV roof. It provides a fast, easy fix for leaks and other issues. However, a potential drawback of using roof repair tape is that it eventually dries out and deteriorates because it’s constantly exposed to the sun. When this happens, you can’t simply apply another layer of roof repair tape.  Not only that, but worn-out tape is very difficult to remove without damaging the roof membrane. With that being said, roof repair tape can sometimes be useful for emergency repairs, when there is no other choice. 

In my excperience, when it comes to sealing up your roof, it’s best to stick with the product your RV manufacturer recommends. Fortunately, sealing your RV roof with RV lap sealant is easy and can be done fairly quickly. Here’s what you need to know about resealing your RV roof.

 

What You’ll Need 

• Ladder (if your RV doesn’t have one)
• Nitrile gloves
• Mineral spirits
• 2 drip free caulking guns
• Tube of self leveling RV roof sealant to seal around extrusions 
• Tube of no-sag to seal the edges of the roof
• Your RV manufacturers recommended self leveling and no-sag roof sealant
• Soft, lint free cloth

 

How To Inspect And Reseal Your RV Roof

1. Check with your RV manufacturer to find out which roof sealant they recommend. 
2. Make sure your RV roof is walkable before getting on it. If it’s not walkable, consider taking it into an RV repair facility and have them do the inspection for you. (You might be able to inspect the roof of a smaller RV from a ladder.)
3. If your RV roof is walkable, begin at the front roof seam and work your way to the back, watching out for tripping hazards like roof top fans, acs, and aerials.  
4. Carefully inspect the seals and roof membrane for  damage as outlined above. 
5. Small holes in the roofing membrane can be sealed with a dab of no sag roof sealant.
6. If the roof seals are showing fine cracks or other signs of wear and tear, you’ll want to reseal with self-leveling sealant, which can usually be applied directly over the old sealant.
7. Wipe the area to be sealed with a cloth dampened with mineral spirits. This will help the new sealant adhere.
8. On flat sections of the RV roof, use self-leveling sealant. 
9. Insert the tube of self leveling sealant in your caulking gun. Then cut a hole in the tip at an angle of about 22 degrees about one-quarter inch from the end.
10. Working in two-foot sections, apply two parallel beads of sealant on either side of the existing sealant for the entire length of the existing bead of sealant.
11. Work another bead of sealant back and forth between the two parallel lines, from one line to the other for the entire length of the original bead of sealant. The self-leveling sealant will level itself to fill in gaps.
12. Along the edges of the RV roof, where self-leveling sealant would drip, use no-sag sealant.

 

The Difference Sealing Up Your RV Can Make

By taking the time to inspect and seal up your RV for winter weather, you can rest easy knowing that your investment is protected. Inspecting seals and resealing where necessary is an easy task that pays off in peace of mind, and having your RV all ready for the camping season.  

Note: If you have balance problems or are uncomfortable with ladders and/or heights, it’s well worth hiring a certified RV technician to do the job of resealing your RV.