Ceiling & Bathroom Fan Installation in Vancouver
The bathroom fan is the cheapest piece of moisture control in a Lower Mainland home and the one most often undersized, badly ducted, or switched off before it has done anything. Get those three right and most bathroom mould problems disappear.
Sizing CFM to room volume
The industry rule of thumb for a bathroom under about 100 square feet is roughly one CFM per square foot, with a sensible minimum regardless of how small the room is. Larger bathrooms, and those with a separate enclosed shower or a jetted tub, are sized by fixture rather than by floor area.
Undersizing is the norm rather than the exception, particularly in older installations where a small fan was fitted to a room that has since gained a bigger shower. Building code sets minimum requirements and they are worth confirming for your specific case — but in practice, going a step up from the calculated minimum costs very little and works considerably better.
Ducting to outside, never the attic
The duct must terminate outside the building — through the roof or a wall with a proper hooded termination. Venting into an attic or a soffit dumps warm wet air into the roof structure, and in this climate that grows mould in your own roof within a season or two.
It is depressingly common in older homes, and people discover it during a roof replacement. Use rigid or semi-rigid duct on as short and straight a run as possible, insulate any section passing through unheated space so it does not condense internally, and check the exterior flap actually opens rather than being painted shut.
Noise ratings (sones) compared
Fans are rated in sones, and the number predicts whether the fan gets used. Anything around 0.3 to 1.0 sones is genuinely quiet — you have to look to check it is running. Around 2 sones is noticeable. At 3 and above people switch it off, which makes an otherwise correct installation useless.
Quiet fans cost a little more and are worth it every time. A large, slow-running fan moves the same air with much less noise than a small one working hard, which is another argument for going a size up rather than exactly to the minimum.
Humidity sensing and timer switches
The fundamental problem is behavioural: people switch the fan off as they leave, when the room is still saturated. A humidity-sensing switch runs the fan until the room actually dries and then stops, which removes the decision from the person.
A timer switch is the simpler alternative — press it and the fan runs twenty or thirty minutes and stops itself. Either is a small upgrade with a disproportionate effect on whether your bathroom develops mould. Switch work goes to a licensed subcontractor; we handle the ducting, the opening and making good.
What this costs
$370–$3,200 for most work
Performed by a licensed subcontractor, who pulls any permit under their own licence. Device and fixture replacement is a minimum-callout job. New circuits, dedicated runs and anything involving the panel are quoted individually and may carry a permit cost on top.
Materials are always separate from labour and passed on at cost. Quotes are free and written, and the full rate card is published rather than given out on request.
Common questions
What CFM does my bathroom need?
The common rule of thumb is about one CFM per square foot for bathrooms under 100 square feet, with a minimum regardless of size, and sizing by fixture for larger rooms or those with an enclosed shower. Confirm the code minimum for your case — but going one step above the calculated figure costs little and performs noticeably better.
Can a fan vent into the attic?
No, and doing so is one of the more damaging shortcuts in a wet climate. It dumps warm moist air into the roof structure and grows mould in your own roof. The duct must terminate outside through a proper hooded vent, on as short and straight a run as possible, insulated wherever it passes through unheated space.
Why does my bathroom still get mouldy?
Usually one of three things: the fan is undersized for the room, it vents somewhere other than outside, or it is switched off before the room has dried. A humidity-sensing or timer switch fixes the third, which is the most common. Check where your duct actually terminates before assuming the fan is at fault.