Does my bathroom need a fan?

October 30, 2011 9:56 AM

Does my bathroom need to have a fan?

I'm in Nova Scotia if that makes a difference in the building code requirements.

My house has two bathrooms. The upstairs bathroom has a fan. Downstairs, no fan. The downstairs bathroom is on a floor that is half below and half above grade - the bathroom is in the front of the house and is about 60% below grade. It has a normal sized window (identical to upstairs) and it's hard to tell how low the room is without looking out the window.

Every time someone showers in the room, the walls (and window, and mirrors) get a lot of condensation on them. You can see the moisture drips on the walls and these drip patterns, if you scrub at them with water, leave an orange residue. I'm sure this is mildew from too much moisture.

It's always kind of bothered me that there is no fan in the bathroom. I know I could just open the window every time I shower, but it gets cold cold cold in the winter. Plus, the level of the room means it would be really easy to climb in/out of the window, so I get a little paranoid doing that when I'm home alone.

The main question is - should this bathroom technically have a fan? I just can't understand why there isn't one. My parents had the house built so it's not a renovation done incorrectly. I think installing a fan would be difficult as there is no simple way (that I can see) to vent the fan exhaust as the outside wall is covered in brick.

If a fan isn't a requirement, why isn't it? What can I do (short of opening the window every time, which is only minimally helpful) to reduce the amount of moisture that accumulates on the walls? Special paint?

posted by sarae to home & garden (13 answers total)

There is special paint, but really, a fan would make all the difference - and you've seen how bad mildew gets already without one. You could talk to a handyman and see if it'd be a relatively small job - I don't think the brick is as big of a barrier as you might think.
posted by ldthomps at 10:08 AM on October 30, 2011 [1 favorite]

So, in the town in the country in the state in the US where I lived a few years ago, the code (whether it was town or county or state I do not know) required a fan in bathrooms where there wasn't a window. The idea was that there had to be some kind of external ventilation.

When we renovated our bathroom, it turned out that the fan vented to the attic, which wasn't ideal either. (We updated it so it vented to the outside.)

For what it's worth, bathrooms with fans often get a lot of condensation.

Could you try leaving the bathroom door open when you shower? Or cracking the window a teeny tiny bit?

Also, in terms of renovation: maybe ask someone to come in and give you a quote for adding an exhaust; they might be able to see a possibility you don't (and the quote should be free).
posted by bluedaisy at 10:11 AM on October 30, 2011

At least in California, if your bathroom has an operable window (it might have to be a certain size), it doesn't need a fan. All the building code cares about is that the room is ventilated somehow.

Even if you did have a fan, you'd still have some amount of condensation inside the bathroom.
posted by LionIndex at 10:11 AM on October 30, 2011

We had a similar situation, and ended up putting in a fan and tiling the part of the ceiling that was most exposed to moisture buildup. The previous owner had tried special anti-mildew paint and it didn't work.

I don't know about your building code requirements, but from a common sense point of view, yes, you should have a fan. The moisture has to be removed somehow. Special paint will only get you so far; you'll do a lot better if you're able to just get that moisture out of there.

It's possible that the building code specifies that a bathroom must have either a fan or a window, and since you've got a window they decided to skip the fan. But you are experiencing the down side of that compromise.

Or, is it possible that this bathroom was originally built without a shower? Showers put a lot more moisture into the air than other bathroom uses, even baths.

You could try running a dehumidifier? But it will take up space, take more electricity to run than a fan, and you'll need to empty the pan.

You could try putting the fan into the top half of the hole for the window, and replacing the bottom half of the window with a casement window or some other style that would allow you to open the window. I believe it's better if the fan can be higher up to pull out the rising hot air.
posted by LobsterMitten at 10:12 AM on October 30, 2011

You could also get a small free-standing fan (like the kind you put on a table or dresser) and put it on the floor and run it while you are in the shower, to try to pull some of the moisture from the bathroom into the rest of the house.
posted by bluedaisy at 10:13 AM on October 30, 2011

I agree that brick is very easy to cut through for a person with the right tools. The fan could vent right out of the wall or through the ceiling. If it goes through the ceiling, the vent hose/pipe will need to follow the direction of the joists (rather than cutting holes through them and weakening your ceiling.
posted by bonobothegreat at 10:15 AM on October 30, 2011

I have lived in various places in both the U.S. and Canada, and the only time I've lived in a place that had a fan in the bathroom is when the bathroom had no window. I agree with those who suggest that it's really just necessary that the room simply must be ventilated in some manner.

And to be honest, I've had (mild to not-so-mild) mildew problems in both kinds of bathroom, so I can't be of much help there. Taking less steamy showers helped, as did wiping away the drippy condensation after a shower, but not sure how helpful that is for you.
posted by sm1tten at 10:57 AM on October 30, 2011

"If a fan isn't a requirement, why isn't it?"

Ventilation has been required by code in Canada for years however an operational window satisfies that requirement as will an intake port for an HRV if your house is equipped with one.

A brick exterior isn't much of a problem when cutting a hole. Use of a diamond hole saw for a round vent or even just removing whole bricks for a square vent is straight forward.
posted by Mitheral at 11:41 AM on October 30, 2011

If you have no intention of opening the window every time you shower, install the fan.

Especially if it's particularly rainy at any time of the year.
posted by bilabial at 12:29 PM on October 30, 2011

Thanks for all the responses! Unfortunately it is still my parents' house and their opinion is that if the builders didn't include a fan, we don't need one.

I certainly don't have the money to do the project myself (let alone hire someone), but it's good to know that there are options I can present to them. I may be able to talk them into something. The brick thing isn't so much an issue of going through the brick as it is the aesthetics as this would be at the front of the house. Also, the fan-in-the-window solution wouldn't go over well as the window is in the front of the house.

The other reason I don't like opening the window each time is that I tend to forget to shut it and then leave the house, leaving a really great entry point for someone who wanted to break in.

I may try leaving the door open a crack and a fan pointed out the door.

Feel free to add more suggestions :)
posted by sarae at 12:41 PM on October 30, 2011

If they ever decide to sell the place, the lack of a fan is going to come up as a red flag on the home inspection. When we were looking for a house many years ago, things like this add up to people moving on to other houses.
posted by fifteen schnitzengruben is my limit at 3:35 PM on October 30, 2011

I used to live in a ground floor flat. As there was no space for a ceiling exhaust fan, there was one installed in the window that did pretty much as good a job as a ceiling one would have done.

It looks like window fans are actually a thing. It seems you can get temporary ones, or you could build one into the window somehow to make it permanent.
posted by peppermintfreddo at 4:40 PM on October 30, 2011

I'd open the window a tiny bit, just to let the air move around. For the security issue, assuming it's a standard sash window (one where it slides up and down vertically) is to have a piece of wood cut so that when placed on top of the bottom sash along the window casement, it will prevent the window from opening more than an inch or so. Crude, but effective.
posted by Kadin2048 at 5:34 PM on October 30, 2011