Bathroom Fan Replacement in Dartmouth & Halifax

Why is water dripping from my bathroom fan in winter?

Because the duct is doing what a cold pipe full of warm wet air always does. The fan pushes humid air into a duct running through an unheated attic, the air cools, the moisture condenses on the inside of the duct, and it runs back down to the lowest point, which is the fan.

It is almost never the fan itself failing. It is the duct being uninsulated, or sloping the wrong way, or long enough that the air gives up its heat before it gets out. The fix is the ducting: insulated, as short and straight as the roof allows, and pitched so anything that does condense runs away from the fan rather than into it.

Does a bath fan have to vent outside?

Yes, and this is the single most common fault found in older HRM bathrooms. A fan that terminates in the attic is not ventilating the bathroom, it is moving the moisture from a room you can see into a space you cannot, where it lands on the underside of the roof.

The signs are worth knowing: frost on the roof sheathing in winter, damp insulation in one spot, a musty smell in the attic, or mould appearing on a bathroom ceiling that has a fan which “works”. If your house has had a fan added by a previous owner, it is worth having somebody put their head in the attic before deciding the fan is the problem.

Why does my fan run but clear nothing?

Usually the duct, occasionally the fan. A flexible duct that has been crushed, kinked around a joist, or run for a long distance with several bends will choke a perfectly good fan. So will a backdraft damper stuck shut, or an exterior vent hood full of lint or blocked by a bird’s nest.

The order to check things in is exterior vent, then duct, then fan. Replacing the fan without looking at the other two is how people end up with a second new fan that also clears nothing.

Where should it vent to?

Through the roof or out a gable wall, with the termination somewhere the moist air is actually leaving the building. The one to avoid is venting into a soffit, because a soffit is an intake: the air you just pushed out gets drawn straight back into the attic through the vents beside it, which is the same outcome as not ducting it at all, with extra steps.

Which route suits a given house depends on where the bathroom sits and what is above it. A bathroom under an attic has options; one under a second storey, or in a house with a flat roof, has fewer, and that is the conversation worth having before the fan is bought rather than after the hole is cut.

What happens during a replacement?

The old fan comes out, and the first real look at the duct happens at that moment, because that is the first time anyone can see it. A straight swap where the ducting is sound and the opening matches is short work. Where the duct turns out to terminate in the attic, or the new fan needs a larger opening cut, it becomes a longer job.

That uncertainty is worth knowing about in advance rather than being surprised by, so it gets said on the phone: the fan is predictable, what is above the ceiling is not, and you will be told what is up there before anything else is decided.

What it costs

A fan replacement starts as a service call, from $249, and the variable is everything above the ceiling. A like-for-like swap onto existing sound ducting is contained. Re-ducting a run to get it properly outside, or cutting for a larger unit, is more.

Where a bathroom is being renovated anyway, the fan is much cheaper done as part of that work than on its own later, because the ceiling is already open and the in-wall heat and GFCI work is happening at the same time.

Permits and inspection in Nova Scotia

Replacing an existing fan is generally within the device replacement exemption in the Electrical Code Regulations, and a new fan on a new circuit can fall inside the single-branch-circuit exemption. Both apply only when a construction electrician does the work and keeps a record of it, which our guide to doing your own electrical work covers in the regulation’s own words.

Permits, where needed, come from Nova Scotia Power Inspection Services acting for the province rather than from HRM.