Signs the slide is letting water in
Check these with the slide both extended and retracted.
- Musty odor strongest near the slide or in the cabinets under it
- Dark staining on the slide floor edge or the carpet next to it
- Bubbling, soft or swollen flooring at the slide corners
- Flattened, torn or shrunken rubber wipers and bulb seals
- Water marks on the inside of the slide fascia
- Ice or standing water on top of the slide roof after snow
How slide leaks happen
A slide room has two sets of seals: wiper seals that sweep the walls as the room moves, and bulb seals that compress when the slide is fully in or out. Sun and cold harden rubber over time, and a seal that has been folded under or torn will channel water inward rather than shed it.
The top of the slide is a flat surface. Without a topper awning, snow, leaves and pooled rain sit there, and when the slide is retracted, that water and debris can be pulled inside along the top seal. On the Front Range, a late-season snow on an extended slide is a common start to a leak.
Water that gets in usually runs down to the lowest point, which is often the slide floor or the corners where it meets the main floor. Those floors are typically wood-based panels that absorb water and hold it, which is what produces the lasting mildew smell.
What happens after a slide leak
- First day
- Water wicks into carpet edges and the slide floor; no smell yet.
- Within a few days
- A damp, earthy smell starts, strongest when the coach is closed and warm.
- Several weeks
- Mold growth is possible on the underside of flooring and carpet pad; stains may appear.
- Months
- Floor panels may soften or delaminate; odor becomes persistent even after drying the surface.
Stopping the leak and the smell
Find the entry point
With the slide out, inspect wipers and the top seal. With it in, inspect bulb seals from outside. A hose test, done carefully with someone watching inside, can confirm the path.
Repair seals or topper
Torn seals and damaged toppers should be replaced. An RV technician can also check slide adjustment, since a room that does not close evenly leaves gaps.
Dry and assess the floor
Pull back carpet if you can and check the floor panel. A floor that stays soft or smells strongly after drying may need sections replaced.
Treat what remains
Once dry and sound, clean surfaces, replace or treat carpet pad, and address lingering odor in the cabinets and fabrics near the slide.
Common questions
Can I just use a dehumidifier?
A dehumidifier helps dry the air and surfaces, but it will not stop a leak or remove mildew already growing under the floor. Fix the leak and inspect the floor first.
General information for the Denver area, not a quote or professional advice. In an emergency, call 911.