Wind noise and water leaks can be things of the past with the proper caulking.
By S.B. Jackson
March 2006
Water leaks and air noise do not have to be part of the motorhome experience. Areas that can be susceptible to water leaks and air drafts include sinks, windows, and roof components such as the antenna, air horns, and vents. These points of entry all rely on sealants to provide an impermeable seam. Protect these target zones by making regular inspections and replacement of caulking a part of your RV maintenance schedule.
Caulk is a waterproofing compound used to close a seam or a joint, and it will dry out and crack over time. This process may accelerate in motorhome use as a result of flexing caused by road travel and also from exposure to all types of climates. Carefully examine seals for signs of wear and replace on an as-needed basis.
A variety of caulking choices are available, and most are designed to suit a particular sealant need. Acrylic and latex caulking are water-based and adhere well to glass, metal, wood, and PVC pipes. However, keep in mind that acrylic and latex will offer little flexibility and can deteriorate from long exposure to ultraviolet (UV) light. Urethane is another good all-purpose caulk and is also available in spray foam for hard-to-reach areas. Urethane, like acrylic caulking, offers limited flexibility and also is sensitive to UV light. Silicone caulking is flexible and generally long lasting, but it also may be more costly, and you’ll want to make sure it is mildew- and stain-resistant. Sealant tape should be used only if recommended by the RV manufacturer.
Taking a close look at the area to be sealed will help you to make a cost-effective decision on what to use as a replacement. If the seam or seal is designed to flex, you may want to avoid acrylic and, in many cases, urethane caulking. Adhesion is another important factor. Test to be sure the substance will stick to the surface before attempting to seal the complete seam. This is particularly important if you are using a substance to replace a previous silicone seal. When you acquire any new sealant, be sure you have on hand the recommended cleaning solvent to help wipe up spills.
Before applying new caulking, it is a good idea to remove the old caulking to help ensure a strong seal. Use a plastic putty stick or sharp, pointed tool to take off old sealant. Careful use of an old-fashioned bottle cap opener also can be effective in grabbing the caulking and pulling it away. Work slowly to avoid chipping or scratching the surrounding area. Once all old sealant is removed, thoroughly clean the area and allow the surface adequate time to completely dry.
Apply masking tape 1/8-inch from each side of the exposed seam to help lay a straight seal. Some caulking material is applied by squeezing the tube. Do this by bending over the bottom end and pressing upward. If a particular type of sealant requires the use of a caulking gun, you may find it helpful to use one with an easy squeeze handle and smooth no-slip ratchet. (Note: According to Environmental Protection Agency standards, caulking can emit pollutants, and work areas should be well ventilated. You may also wish to use plastic gloves to protect your hands and to ease cleanup.)
Cut the applicator tube at an angle; how high or low depends on the amount of material you want to squeeze out. Starting at one end, rest the tip of the caulking tube on the joint and squeeze out a smooth, even application while slowly pulling the tube. Release the trigger before pulling the gun away from the surface. Start small and be conservative, but don’t skimp. A solid layer of caulking is your best defense against water intrusion. It is easier to go back and add caulking than to remove excess.
Some caulking tube ends are designed for replacement tips to access hard-to-reach areas, or you can attach flexible tubing with duct tape to use as a nozzle extension. You may want to fill sinks with water prior to caulking to expose the gap created by the added weight.
Apply caulking in increments and stop to smooth the surface before the material has time to harden. To even out acrylic caulking, run a wet fingertip along the surface. Keep a stack of cleaning rags or a roll of paper towels nearby to wipe away caulking from your fingertip. Smooth out silicone and urethane caulking surfaces by using a plastic spoon or a caulking tool designed for this purpose. Allow the caulking to completely dry before exposing the area to water.
Caulking is an easy and inexpensive way to safeguard against the elements. Keep sealant in your motorhome in tip-top shape and get the peace of mind that comes with knowing that the weather is staying outside where it belongs.