Leaky RV Slide Out Room Repair and Reseal

After our extended snowbird trip down south I like to go over our Cougar fifth wheel trailer with a fine tooth comb looking for defects. This spring I discovered a small leak in one corner of the slide out room. Luckily it hadn’t had a chance to progress too far. Still, though, it had weakened a small area of the floorboard.

I found the leak was caused by a small opening in the external silicone sealant. Silicone caulking will dry out over time leaving openings for water to penetrate. Water had seeped in over time and wetted the floor board making it a bit spongy. Given enough time I’m sure it would have rotted away completely and led to a structural failure of the slide room. Glad I caught it early!

To repair the problem, I first removed the external flange and scraped away the old silicone caulk using a plastic chisel, scotch pad, and my thumbnail. To help loosen up the old caulking, I use a product called “Goo Gone Caulk Remover.” With around a 1/2 hour of effort, I was able to get rid of pretty well all the old silicone. Extremely important as nothing will stick to silicone.

Tools to remover old RV sealant

Next, I drove several 1 1/4 inch Tek Screws through the affected board area and into an aluminum beam above it. I made sure the screw was countersunk into the wood as not to catch when the slide is drawn in. It firmed the area up enough to retain its origin structural al integrity.

Finally, I reattached the metal flange and resealed it with a product called SikaFlex 291, a high-end marine grade sealant. I smoothed out the SikaFlex and made a smooth seam using a special caulking tool. The tool comes with multi-sized flexible trowls. Then cleaned up the overflow bits and let cure.

RV Slide Out Leak Repair Video

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