June 30, 2026 · 4 min read
Why a Small Leak Becomes a Big Problem
RV walls are usually built as a sandwich. A printed outer fibreglass skin is glued to a layer of foam or wood framing, which is glued to the interior panel. As long as those layers stay bonded, the wall is strong and light. When water gets between them, the glue breaks down and the layers separate. That separation is called delamination, and once it starts it tends to spread.
The trouble is that water rarely enters where it shows up inside. It can run along framing, soak insulation, and sit against wood for weeks before you notice a soft spot or a bubble in the wall. By the time the outside skin looks wavy or feels loose, the framing behind it may already be rotten.
Alberta makes this worse. Our freeze and thaw cycles let trapped water expand and contract over and over, which works seals loose and opens tiny gaps a little wider every season. A leak that would creep slowly in a mild climate can move much faster through a Calgary winter.
The Early Warning Signs to Watch For
Start with your senses. A musty or damp smell when you first open the door, especially after rain or snowmelt, is one of the earliest signals. Soft or spongy spots in the floor, walls, or around windows mean water has already been sitting there. Stains, dark streaks, or discoloured paneling near the ceiling, slide-outs, and corners are worth a closer look.
Outside, run your eyes and your hand along the body. Bubbling, rippling, or a wavy reflection in the fibreglass is a classic sign of delamination starting underneath. Look closely at every seam and seal, including the roof edges, around vents, the awning rail, marker lights, and any place a screw or fixture pokes through the skin. Cracked, peeling, or chalky sealant is an open door for water.
Inside cabinets and storage bays, check for water marks, rust on metal, or swelling at the bottom edges of wood. A simple habit of looking after every heavy rain, and once in spring and fall, catches most leaks while they are still cheap to fix.
Simple Habits That Keep Water Out
Sealant is not a one time job. The lap sealant on your roof and the caulking around windows, vents, and trim age out, dry up, and crack, often within a few years. Inspecting it a couple of times a year and resealing as needed is the single most effective thing most owners can do to prevent leaks.
Keep the roof clear and drainage paths open so water runs off instead of pooling. Check that windows and slide seals close fully and are not cracked or torn. When you store the RV, a cover or indoor space helps, but a leak can still develop in storage, so a quick look before and after winter matters.
If you do find soft sealant or a small stain, address it early. Resealing a seam is straightforward. Replacing a rotted wall section and re-bonding skin is not. The cost gap between those two jobs is the whole reason to catch leaks early.
When to Bring It to Horton in Calgary
Some things are worth doing yourself, like routine sealant checks and keeping an eye out for stains. But if you find a soft spot in a wall or floor, see rippling in the outer skin, or smell persistent mustiness you cannot trace, it is time to have it looked at. Those are signs the problem may already be behind the surface.
At Horton RV Services in Calgary we can track down where water is actually getting in, check how far any damage has spread, and handle the repair properly so the layers bond again and the structure stays sound. We also help document leaks and damage for insurance claims when that applies.
The earlier you bring a suspected leak in, the more options you have and the less it usually costs to fix. If something feels off, it is worth a look before another Alberta winter has a chance to make it worse.
Common questions
How can I tell the difference between a stain and active water damage?
Press on the area. If it feels soft, spongy, or gives way at all, water is or has been sitting there and the material may be compromised. A dry, firm stain may be old, but any softness, swelling, or musty smell points to active or recent moisture that should be checked.
How often should I reseal my RV in Alberta?
Inspect your roof and exterior sealants at least twice a year, typically in spring and fall, and reseal anytime you see cracking, peeling, or gaps. Alberta's freeze and thaw cycles age sealant faster, so a regular check is more important here than in milder climates.
Can delamination be repaired, or do I have to replace the whole wall?
It depends on how far it has spread and whether the framing behind it is still sound. Caught early, a limited area can often be repaired and re-bonded. Once rot reaches the framing or the delamination is widespread, more involved structural work is needed, which is why catching it early matters so much.