No one wants to plan a trip and start loading up the RV only to discover, just before time to take off on that long-awaited journey, that, due to a leaky skylight, things have gotten a bit damp inside since the last roll down the road. Pencil in an annual skylight check on your calendar to check for damage and seal problems. Resealing an RV skylight requires removing the entire piece so you can clean and prep for a new, sealed bond, but it's important to give it attention whether you take it to a pro or do it yourself. Depending upon when you catch the problem, a skylight with a poor seal can cause damage inside your RV ranging from barely noticeable to serious. Resealing isn't a tough job — just one you'll be glad you did in advance.
Diagnose the Damage
Before you start working, make sure the skylight is the actual leak source. Leaks can develop in the roof and along the seams between the roof and the exterior walls, possibly causing structural damage that must be addressed to prevent serious rotting and mold. So, inspect your seams and exterior structure for potential leak sources. If it begins to appear that the skylight is, indeed, the problem point, dump a bucket of water directly on the closed skylight and have another person stand inside to identify the leak. When you determine the skylight is the source of the problem, move forward with the repairs.
Items you will need
Bit to match existing screws
Carefully climb on the RV to access the skylight. Take all the materials with you.
Remove the screws and use the putty knife to ply the skylight free. Cutting under and around the edges will eventually work the entire piece loose. Save the screws.
Scrape the RV roof surface with the putty knife until all the old sealant is removed. Also scrape the skylight base to remove sealant. A clean surface will create a tight bond.
Apply sealant to each screw hole. Also apply a bead on the outline from the skylight base. Set the skylight on the sealant and work into the original position. Apply slight downward pressure to create an even bond.
Apply a small amount of sealant to each screw and drill the screws back through the existing holes.
Use an old rag or paper towels to clean any excess sealant from the roof and your hands. Leave the RV for at least one day while the sealant cures.