Do you grow mushrooms in your RV? An RVer we know recently found out that he did—quite unintentionally. Shutting the door to the rig last December, he figured all was well until he reopened it at the end of March. Underestimating the power of the Pacific Northwest rain system, he was quite surprised—and dismayed—to find a crop of mushrooms growing up in the middle of his living room floor. Another RVer acquaintance, far removed from the Pacific Northwest, was quite astonished when a sudden Southern California rainstorm blew into his RV through a closed living room window.
We may think of RVs as being a wonderful shelter from the storm, and they are, provided we keep up with the maintenance. Perhaps one of the most neglected forms of RV maintenance is keeping up with seals. Wherever the skin of an RV has something go through it—a window, door, plumbing vent, TV antenna, the list goes on—is a point the manufacturer sealed to keep out moisture. All those sealant points must be maintained. Most of us think about roof-level seals, but how many concern themselves with what penetrates the wall skin?
It may be good to take a pen and paper and make a good inspection of your rig. Here’s a list of points to check:
Rooftop: TV antenna. Radio antenna. Skylights. Roof vents. Plumbing vents. Joints between roofing (common on metal roofs). Air conditioner. Solar panel mounting hardware. Satellite dish mounts.
Walls: Windows. Doors. Range vent. Awning hardware. Power connectors. Plumbing concerns. Doorstop hardware. End corner trim. Trim where wall sections butt together. Running and safety illumination lights.
So now you have a list; what are you looking for? The easy ones are where sealant materials are obviously cracked and weathered. Up on top, most leakage candidates are fairly obvious. The sneakier ones are around wall penetrations. Windows and doors that suddenly start leaking, or leak when you hit the first rain may “look” just fine. Some RVers simply resign themselves to a maintenance schedule of say, every five or six years popping out the windows and doors and laying in a new seal.
Sound a little excessive? The RVer with the mushroom crop can tell you it isn’t. When he bought his fifth wheel it was a pre-owned unit, and within the first year of owning it, he resealed all the windows. The entry door was replaced five years ago. What was leaking? Closer examination revealed the entry door and a corner seal at the end of the rig were the villains in the play. The California RVer bought his rig used two years ago. Now it is 10 years old, and he not only is fighting with window seal issues, he has also reported problems with leakage from roof-mounted vents.
How do you renew your seals? Here are a few general tips:
First, you’ll need to remove the unit that needs resealing. Be it a window, door or vent, the process is pretty much the same. Remove the mounting screws and carefully run a putty knife between the unit and the rig surface. Windows are often held in place not only with mounting screws, but at times may be stapled or otherwise affixed to the rig from inside as well. TV antennas are a different animal—you’ll need to pull the inside hardware off first, then attack the antenna unit from up roof side.
With the unit pulled out, carefully clean off as much of the old sealant as possible. A good scraper will help; we like the “five-in-one” style painter’s tool available at most hardware stores. Remove all the old sealant from the rig wall or roof as well. When cleaning sealant off rubber roofing, DON’T use chemicals that are petroleum or citrus-based.
Most units are sealed with putty tape. (An exception to this is roof-mounted air conditioners, which have a special gasket that mashes between the unit and the roof. It’s best to get a new gasket any time you remove an air conditioner.) When we say putty tape we really mean butyl tape. The less-expensive putty tape will damage EPDM rubber roofs, and from our experience just doesn’t last nearly as long as butyl.
If you’re working in warm weather, here’s a tip for working with sealant tape. Stick the rolls in the freezer or refrigerator until you’re ready to work with the stuff. It will peel back off the roll with much more ease and a whole lot less frustration. Run at least one layer of the butyl tape around the flange of the unit you’ll be mounting, and if the surface of either the unit or the RV is less than smooth, you might consider using more than one layer. Firmly press the tape onto the flange, and remove the backing paper when you’re ready to remount the unit.
After the unit is screwed back in place, carefully use your putty knife to trim away the excess butyl tape that squishes out from under the newly mounted unit.
Many RVers like the extra protection of adding a bead of liquid sealant around the edges of a newly mounted unit, and some add a dollop to each screw head. If you choose to do this, be sure the sealant you’re using is compatible with the surrounding surface. We say this because some sealants will damage EPDM rubber; we stick to Dicor lap sealant for roof work. We’ve also sworn off the use of sealants that contain silicon. Silicon sealants are next to impossible to remove, and nothing, repeat NOTHING, will stick to them. If you later wanted to run a bead of sealant where the silicon was previously used, forget it—it won’t stick. We’re sold on acrylic caulks from the RV store.
Is it a lot of work? Absolutely. But skimp on the maintenance and let rain’s moisture in and you’ll soon find more wet: bitter tears when you work to fix the damage caused by moisture intrusion.
Russ and Tiña De Maris are authors of RV Boondocking Basics—A Guide to Living Without Hookups, which covers a full range of dry camping topics. They are also authors of Camp Hosting USA—Your Guide to State Park Volunteering. Visit icanrv.com for more information.