Dear Dave,
A fellow RVer has a leaking RV window. I told him to buy butyl tape, remove the window and reinstall with fresh tape. The local Home Depot did not have butyl tape in stock and sold him some other tape (couldn’t remember the name). They said it worked great for RV windows. Hopefully, you can give me a quick turnaround before this guy does something foolish.
Is there a suitable alternative to butyl tape for reinstalling his leaking window? If so, what? I would sure hate to see this guy do the repair only have to do another cleanup and repair the window seal correctly. —Jim
(Generic question regarding any laminate-sided RV with aluminum windows.)
Dear Jim,
Butyl tape is a synthetic rubber adhesive that we commonly called “putty tape,” as it has the consistency of flexible putty rather than a silicone or harder rubber. It is used as a sealant between two surfaces that are basically sandwiched together, like the frame of an RV window and the sidewall or areas where trim is applied. It’s a good application for exterior sealing as it does not dry or crack as fast as rubber, is very pliable, and can be wrapped around edges such as the corners of windows.
Benefits of butyl tape
Butyl tape is a great sealant against moisture penetration and does not ooze or “creep” like most silicone sealants. It typically does not harden and crack. However, the more it is exposed to harsh sun, the more likely it is to harden and crack. I have had to replace it on several windows.
I am surprised that Home Depot did not have actual butyl tape available, as I have purchased it at my local Home Depot store and I see on their website that it is available for pick up. The size I have used in the past was the 3/16” thick by 7/8” wide, as the flange of the window is about that width.
Not knowing what product he did get, I doubt the average Home Depot assistant has had much experience with working on RVs, so I would question what he purchased. I would stay away from the window and door flashing tapes, Flex Seal, and other waterproofing repair tape.
The material needs to be pliable and not break down with extreme temperatures. I’m not sure what part of the country you are in. However, where I am we get below-zero temperatures and well above 100. That can be brutal on anything that is not a synthetic rubber material.
If your friend can wait a few days, purchase the Dicor Butyl Tape on Amazon here.
If it is simply a rubber seal that would be a typical weatherproofing-type “gimp” material used around doors and windows, it will not stick to the two surfaces and will eventually creep out and not seal. If you can provide the RV make we can research a little closer. Otherwise, I would not use it and find an actual butyl tape either at another home improvement store or Ace Hardware.
You might also enjoy this from Dave
My RV’s window leaks. Can I fix it with silicone?
Dear Dave,
My RV’s window is leaking rain water. Can I fix it with silicone? The gasket is not that old. I bought the RV two years ago, used, and I think they put it on. —Debbie, 2005 Coachmen Freelander Class C
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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Thank you, Dave! 🙂 It is good to know that this typically is carried by home improvement stores; thank you! Safe travels! 🙂
I used what seemed like “miles” of butyl tape to restore an old sailboat. Store clerks often tried to sell me something other than true butyl tape. Some even called the pretender “butyl tape.” There is no real substitute for butyl tape. Most of the old tape I removed from the 35-year-old sailboat was still pliable.