RVing Women
May / June 2000 edition

While your neighboring RVers are lounging in lawn chairs in the shade of their awning, waving and making annoying comments, you might question why you're crawling around on the hot, sun-baked roof of your RV with a caulking gun.

But then a comforting image appears:  your neighbors on a dark rainy night, fumbling with an umbrella and flashlight while trying to add a bead of sealant to a leaky window.

A warm, dry day is the best time to chase down possible leaks, instead of juggling buckets and squeezing sponges in the first downpour.

Leaks are Inevitable

Leaks often magically appear during the first rain of the season, despite routine maintenance. Even if you are a snowbird and follow the sun, eventually you'll get stuck in a downpour.

Persistent leaks in side walls and roofs can cause serious conditions that can be both difficult and expensive to repair.  Wood frames, paneling, flooring, wood backing on exterior skins and wood roof supports are all subject to dry rot if not properly maintained.

Most water leaks are a result of normal wear and tear.  Bumped over rough roads, warm days, cool nights - after it creaks, bends and flexes, it's amazing most RVs don't leak like sieves.

You can minimize leak problems with regular maintenance and an hour or so on a nice day.

On the Roof

Whether you have a rubber or aluminum roof, there are seams and places that should be inspected at least once a year.

Fill a bucket with the materials and tools you may need, which should include a caulking gun with sealant, rag, butyl tape and a roll of color-matched vinyl insert for the molding trim.  Manufacturers often use number 8x1" screws, so bring a few extra to replace any rusty ones, plus some number 10x1" to replace stripped screws.   Tools you may need are number two Phillips and square-head screwdrivers, a stiff brush, putty knife and kneeling pad.

Divide the roof area in half and work up one side and back along the other.  Old and cracked sealant at seams and around the edges should be replaced.  Carefully remove the old sealant with a putty knife and stiff brush.  Clean and dry the surface before applying new sealant.  Apply sparingly.

Carefully inspect the edge of the roof where the rubber is stretched over the side.   Check for cracks, holes or tears in the sealant or roofing material.  Any suspicious-looking area gets a dab of sealant.  Some sealants are self-leveling or you can use a finger, putty knife or wooden Popsicle stick for spreading.

Check around all attachments on the roof such as roof vents, holding tank vents, skylights, refrigerator vent, antenna, seams along the front or rear cap, ladder and roof railing.  Look for cracks in vent covers and voids around attached accessories.   Also check for rusty screws.  Replace rusted screws, then dab a small amount of sealant on screw heads.

While on the roof, note any soft spots that might indicate underlying wood rot.   Carry a note pad and pen to make note of brand make and size for replacement parts.   Cracked or brittle vent covers should be replaced.

Plumbing vent caps are often made of plastic and turn to chips after a few years of exposure.  If replacement is necessary, consider using readily available metal vent stacks.

Next examine molding trim along seams, looking for voids and cracked insert trim.   The vinyl insert material tends to shrink and should be replaced when necessary.

Inspect fiberglass front and rear caps for stress cracks that might admit water and repair.

Down the Side

Window frames are the most likely problem area.  Some leaks won't appear to be entering at the window, but water may pool and travel along the frame, then run down an inside wall - appearing at a remote location.  Despite the seal between the sidewall and window frame, water can work its way around window frames.

RV leaks often originate around a window, especially the windows located behind the rear axles on trailers and fifth wheels.  While manufacturers recommend you remove leaky windows and replace the seal, this is not always practical.

Another option is to reseal the window.  After removing any old sealant present, apply a new bead of sealant across the top and down the side of the window frame.   Periodically check for voids and reapply.

Another way to prevent leaks is to install an aluminum strip called a drip cap above problem windows.  Drip caps are easy to install and available in various lengths.   They channel and direct water away from the The window frame and are inexpensive.

Although less troublesome, attachments on the side of an RV can be the source of a leak.  Light fixtures, refrigerator service doors, water heater or furnace access doors, electrical or water supply hatches, storage doors or even the trim molding can be the source of a leak.  Awning hardware fasteners and any other accessories which required piercing the siding should also be inspected.  Check the integrity of the seals on these fixtures to determine if they are the problem.

Slideouts

When the slide is extended, check that the seal sits correctly.  Before retracting the slide, always clean the top to ensure debris doesn't interfere with the seal.  An awning that extends and retracts with the slide helps with debris and also channels water off the top during a storm.  Inspect the slide seal periodically for defects and keep it cleaned to maintain its flexibility.

Inside the RV

If you suspect a roof vent is leaking, one way to check from inside the rig is to first remove the four screws attaching the plastic cover.  Remove the cover and crank handle.  Remove the two screws that fasten the screen insert and gently remove the screen.  This gives you a view of the frame of the roof opening.  Look for water stains.   Evidence of a leak indicates you need to reseal or replace the vent.

If you have an air conditioner, it uses the same size opening as a ventilation vent, however a special seal is used.  If you suspect a leak around the air conditioner, first check the tightness of the bolts fastening the air conditioner to the roof.  Do this from inside by first removing the inside shroud.  Most AC units are fastened by four bolts.  Check that the bolts are snug.  Do not over-tighten.  If they are snug and there is a leak, the seal may be compressed and needs replacement.

Problem Areas

In areas where its difficult to trace leaks, or you just can't find the source, try placing newspapers or paper bags in cabinets or suspect areas.  During a downpour, check these papers for moisture to determine if a leak is still occurring.

Making regular inspections for problem areas may seem like a lot of trouble, it's important to aggressively prevent water damage.  An "ounce of prevention is still worth a pound of cure."