Does your bathroom mirror stay fogged long after the shower is off? Is paint bubbling on the ceiling, or are dark spots creeping across the drywall above the tub? If you live in an older home in Ancaster or Hamilton, you’re not alone, and it isn’t something you caused.
Poor ventilation is almost always the cause, and a bathroom renovation is the most lasting way to fix it. That means a properly sized exhaust fan ducted all the way outside, a humidity sensor or timer to run it, and repairs to anything the moisture has already damaged, done while the walls and ceiling are open.
Why do older homes have so much bathroom moisture?
We see it most in 1950s to 1970s bungalows. Back then, a bathroom window counted as ventilation, so a lot of these homes were built without a fan at all. Nobody opens that window in January, so the moisture goes into the ceiling and walls.
The second group we see is 1980s and 90s homes that technically have a fan, but it’s dead, too weak, or venting into the attic instead of outside. We recently opened up a 1960s bathroom with ceiling damage from exactly that.
Our Hamilton-area winters make it worse. Warm, humid air from the shower meets cold exterior walls and ceilings and condenses, and over time that water works its way into drywall, plaster, trim and the framing behind the tile.
How does a bathroom renovation fix ventilation and moisture in an older home?
At JJ Legacy Contracting, we start by finding the root of the problem and how far it has spread. That usually means opening the wall or ceiling where the damage shows, checking where the existing fan actually vents, and seeing what’s behind the surface before anything new goes in. From there, the fix follows a clear order.
- Size the fan to the room and the duct run. As a general guide, a bathroom needs about 1 CFM of airflow per square foot of floor, and at least 50 CFM. Long duct runs and bends cut airflow, so we size up to match. We also choose quiet models so they actually get used.
- Duct it all the way outside. On every bathroom we do, the fan runs through an insulated duct to an exterior vent with a backdraft damper, so moist air leaves the house instead of condensing in a cold attic.
- Run it automatically. A humidity-sensing switch or timer keeps the fan going until the room is dry, without anyone having to remember.
- Repair and protect. Damaged drywall comes out, and tiled walls get a proper waterproofing membrane behind them so the next twenty years look different from the last twenty.
- Let air in. A small gap under the door gives the fan fresh air to pull, which helps it work as designed.
Doing this during a renovation means the ductwork can be routed properly and every problem is fixed before it’s covered up again.
What changes once the moisture is under control?
The difference shows up in small, daily ways. The mirror clears within a few minutes. The room smells clean instead of musty. Paint and caulking stay put, and you stop wondering what’s growing behind the tile. You end up with a bathroom that’s comfortable to use and built to last, in a house you already love.
Frequently Asked Questions
How can I tell if my bathroom fan is working? Hold a single square of toilet paper up to the fan while it runs. If it doesn’t pull the paper against the grille, the fan is too weak or the duct is blocked. It’s also worth checking outside to see whether the exterior vent flap opens.
Is mould on my bathroom caulking a sign of poor ventilation? Not always. Caulking picks up mould over time in almost any shower, and it often just means it’s due to be replaced. When it comes back quickly after recaulking, or shows up on the ceiling and walls away from the shower, that points to a moisture problem worth looking into.
How long should I run the bathroom fan after a shower? About 20 minutes after you finish is a good rule of thumb. A humidity-sensing switch handles this for you by running the fan until the air is back to normal.
Can I just replace the fan without renovating? Sometimes, yes. If the duct already runs outside and there’s no damage behind the walls, a new fan may be enough. If there’s water damage or the fan vents into the attic, a fan swap alone won’t solve it.
If your bathroom has been fighting you for a while, we’d love to talk through the job with you. Book a short qualification call with JJ Legacy Contracting, and we’ll help you understand what’s going on and what it would take to fix it for good.