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How To Deal With An RV Window Leak

Man leaning out open RV window looking at the seal - RV window leak
Don’t let an RV window leak destroy your RV. Photo: Shutterstock

Is Your RV Window Leaking? Here’s What To Do

It’s not uncommon for RV windows to leak. Unlike residential windows, RV windows are subject to the movement and all the bumps and shakes that come with RV travel.

RVs are mass produced often quickly and with the cost to the manufacturer in mind. RV windows are placed in openings that can be very oversized, fastened, and sealed from the outside with butyl tape and caulking. 

The seals can dry out from being exposed to the sun and elements. This, combined with movement from travel, can often lead to leaks. These leaks are small holes that can sometimes be overlooked. The dried caulking can also pull away from the window frame and allow water to enter the wall.

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Small Leak, Big Problems

Water damage can cause serious problems in an RV and has to be taken seriously. A small RV window leak over time can result in a rotten window frame, wall paneling, studs, and flooring.

The tricky thing about water leaks are they are often not obvious, and the damage they are doing is hidden. Water can slowly leak around a window for months and years, rotting wood and growing mold before signs of damage appear.

At the point when signs of water damage start to show through wall paneling, the damage can be very extensive. If you are lucky, water will leak around a window and run down the interior of your RV where you will notice it. Oftentimes, however, the leak will run inside the wall panels and go unnoticed.

So, it’s important to regularly check seals for leaks and repair them properly right away.

Leaky Window Seal Or Window Frame?

We usually think about the seal that is formed between the window frame and the RV wall when looking for leaks. 

This is often the case; however, the window frame also has a seal that holds the glass in place. This seal can shrink or become damaged and allow water to enter the RV.

These seals can be completely replaced, although it is usually just a small section that is the issue. These small gaps, often in the corners, can be filled with a waterproof sealant to eliminate the leak and hide the gap. 

How To Deal With An RV Window Leak

You must first find the leak before you can deal with it. Regular inspections of your window seals will help to find leaks and notice seals that are drying out.

When you do find signs of a leak, the most important thing is to not ignore it. You should also investigate a possible leak location if it looks like it’s been there for awhile. Simply covering up a leak in window caulking with more window caulking may just mask a bigger problem.

This may prevent further water from entering; however, water that has entered may have already done damage and the beginning stage of mold may be already started. 

Exposing the truth

If you have window sealant that has shrunk, cracked, or has a hole, the best course of action is to remove the sealant. Rather than resealing over an area, removing the sealant around the perimeter and resealing it is better.

If you suspect the leak has been there awhile or there are signs of water damage, remove the window. Removing RV windows is very easy and the peace of mind that there is no serious water damage inside the wall is worth the time.

With a window removed, you can better see the window framing and possibly get a look inside the wall. If you find more signs of damage, you must continue to chase the damage. Removing wall paneling or framing to ensure you find and repair all the damage is a must.

Close up of water damage on wooden floor - RV window leak

Resealing RV windows

Not every RV window leak results in a complete reno of your RV. If caught early, window leaks can be easy fixes. 

Take notice of how your RV window is sealed. Most RV windows are installed with a seal between the window frame and the exterior of your RV. The top side of the window where water can sit and where the rain hits most directly needs extra protection. 

Here, most manufacturers use caulking to provide a watertight seal along the top edge. If your RV for some reason doesn’t have this and you have a leak, the seal between the window frame and the exterior is the source of the leak. If so, remove the the window and replace the seal.

Butyl tape is similar to two-sided tape that has a soft rubber-like consistency and easily wraps around the window frame. When replacing this seal, start the application on the bottom side of the window frame and follow the perimeter back to the bottom joint and overlap. This ensures no water will leak through the joint location.

After replacing the butyl seal and reinstalling the window, reseal the top side. If your RV window has the caulking on the top side and it has started to peel, dried up, or has a hole, remove and replace it.

With the caulking removed clean the surfaces and check for water damage beyond this seal. On a clean surface, start a bead of caulking a few inches down one side of the window and continue over the top and down the other side a few inches. This is the minimum and what most manufacturers do. If you choose, you can caulk the entire perimeter of the window.

Prevent Leaks Before They Happen

As always, prevention is key. Regularly inspect your RV to catch leaks before they cause damage. This can save you tons of time and money that can result from prolonged water leaks.

Covering your RV can help prevent the sun from drying out the window seals and keep sitting water from penetrating small pin holes. Keeping the seals clean and using conditioners can prolong their life. The process to remove the exterior caulking and replace it is cheap and easy. So, at the first sign of shrinkage or drying out, replace them.

Make sure you keep track of all your RV maintenance and repairs with an online tool such as RV LIFE Maintenance. Not only can you keep all of your documents in one place, but you’ll also receive timely reminders when maintenance is due to help you avoid costly repairs and potentially serious accidents.

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