# Am I causing my bathroom to rot? **URL:** \ **Category:** Factual Questions\ **Created:** [September 11, 2014, 4:27pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200 "2014-09-11T16:27:33Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Absolute](https://avatars.discourse-cdn.com/v4/letter/a/b2d939/32.png) [@Absolute](https://boards.straightdope.com/u/Absolute)\ **Post date:** [September 11, 2014, 4:27pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/1 "2014-09-11T16:27:33Z")
My bathroom has a single switch for the lights and fan. It is an ordinary, standard construction bathroom in a house built in 2007 or so, with sheetrock walls and a tile floor. The bathroom is entirely on the interior of the house (no windows). I like to take showers in the dark, especially in the morning. I just find it a more pleasant way to wake up than stepping into a bathroom lit up like an operating theatre. Obviously, this means I’m taking showers without the fan running. I do take fairly hot showers, maybe 10-15 minutes long. When I’m done, I turn on the lights/fan, and open the door to the rest of the house. I live in Colorado - the air is usually fairly dry and the indoor humidity in the rest of the house is maybe 40-45%. The house has a good A/C system that I run regularly. Am I risking any damage by doing this: rot, mold, etc.? ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [September 11, 2014, 4:35pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/2 "2014-09-11T16:35:39Z")
You are increasing the amount of moisture in the absorbent materials in the bathroom, and probably you have water condensing in various places and dripping. Some of the bigger problems may be hidden behind walls or under a vanity. However, unless you have some huge fan in that bathroom it’s not rapidly increasing the rate of what will happen eventually anyway. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [September 11, 2014, 4:47pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/3 "2014-09-11T16:47:21Z")
Why don’t you just put lower wattage bulbs in the bathroom? ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [September 11, 2014, 4:57pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/4 "2014-09-11T16:57:37Z")
> [@Really\_Not\_All\_That\_Bright](#): > > Why don’t you just put lower wattage bulbs in the bathroom? good suggestion. what caused that to come to mind? ---
**Author:** ![thatguyjeff](https://avatars.discourse-cdn.com/v4/letter/t/6de8d8/32.png) [@thatguyjeff](https://boards.straightdope.com/u/thatguyjeff)\ **Post date:** [September 11, 2014, 5:00pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/5 "2014-09-11T17:00:50Z")
If you live alone and generally take one shower per day that’s not excessively long - usually allowing the bathroom 24 hours before the next shower - you’re probably okay. The key, for mold especially, is any moisture or condensation built up on anything to dry completely each day or between uses. If you’re like me - with a family of four, a tiny bathroom with the only shower in the house, with a wife who often showers twice per day because she exercises in the afternoon, then that fan probably needs to be on. You can also swap your light switch out for a timer so that you can leave the fan running after you’re finished in the bathroom for some extra fan time that will turn itself off. I know you said the lights are on the same switch, but you can still use the timer for it - manually twisting the timer off after you’re finished with non-shower related bathroom uses. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [September 11, 2014, 5:00pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/6 "2014-09-11T17:00:54Z")
> [@](#): > > what caused that to come to mind? This part: > [@Absolute](#): > > My bathroom has a single switch for the lights and fan. > > \ > > I like to take showers in the dark, especially in the morning. I just find it a more pleasant way to wake up than stepping into a bathroom lit up like an operating theatre. Obviously, this means I’m taking showers without the fan running. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [September 11, 2014, 5:06pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/7 "2014-09-11T17:06:14Z")
Can you install [two switches](https://www.google.com/search?q=dual+light+switch&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb) in the box, and turn the fan and light on independently? ---
**Author:** ![sich\_hinaufwinden](https://avatars.discourse-cdn.com/v4/letter/s/c5a1d2/32.png) [@sich\_hinaufwinden](https://boards.straightdope.com/u/sich_hinaufwinden)\ **Post date:** [September 11, 2014, 5:15pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/8 "2014-09-11T17:15:33Z")
> [@johnpost](#): > > good suggestion. > > what caused that to come to mind? > [@Really\_Not\_All\_That\_Bright](#): > > This part: I think that was supposed to be a play on your user name - low wattage bulbs being not all that bright. I could be wrong though. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [September 11, 2014, 5:22pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/9 "2014-09-11T17:22:00Z")
On (frequent) occasion, I live up to my username. :smack: ---
**Author:** ![48Willys](https://avatars.discourse-cdn.com/v4/letter/4/db5fbb/32.png) [@48Willys](https://boards.straightdope.com/u/48Willys)\ **Post date:** [September 11, 2014, 5:24pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/10 "2014-09-11T17:24:24Z")
> [@Really\_Not\_All\_That\_Bright](#): > > Why don’t you just put lower wattage bulbs in the bathroom? Great name-post combo! X2 on getting a seperate switch for the light and fan. There are duplex switches that will physically fit where a single switch is now. The wires are already there. It should be a five minute job. Here in Colorado, one ten minute shower a day? I would think that you are fine. Me personally, I would put in a duplex switch. I hate foggy mirrors. IHTH, 48. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [September 11, 2014, 5:36pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/11 "2014-09-11T17:36:03Z")
You might try leaving the bathroom door and/or window open when you take showers like this. That will spread the humidity out and should result in less condensation, with or without a fan. Otherwise, I don’t see it as a guaranteed problem, but it’s the kind of problem that is very particular about your exact situation (like number of people using the bathroom and where water condenses). Any problems can remain hidden for a long time before you discover the full extent of the problem. For me, I’d probably settle with leaving the door open a crack since it doesn’t require rewiring the bathroom. As another precautionary measure, it might not be a bad idea to stick one of those dehumidifying jars in your bathroom. DampRid is an example brand name of what I’m thinking about. This would be a small extra step to help reduce any lingering humidity, though it’ll obviously be insufficient to prevent condensation during a shower. ---
**Author:** ![corkboard](https://avatars.discourse-cdn.com/v4/letter/c/e9bcb4/32.png) [@corkboard](https://boards.straightdope.com/u/corkboard)\ **Post date:** [September 11, 2014, 6:34pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/12 "2014-09-11T18:34:49Z")
I’d just install a dimmer. Dim lights in the morning, brighter in the evening. ---
**Author:** ![Emtar\_KronJonDerSohn](https://avatars.discourse-cdn.com/v4/letter/e/58956e/32.png) [@Emtar\_KronJonDerSohn](https://boards.straightdope.com/u/Emtar_KronJonDerSohn)\ **Post date:** [September 11, 2014, 6:49pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/13 "2014-09-11T18:49:26Z")
A dimmer will cause problems with the fan, as they’re on the same switch. A separate switch will require a separate wire to be run. Get a timer switch. I have one for a single switched fan/light and it has six buttons for different durations and one button to turn it on or off. Take the shower in the dark, press the 30 min button, go about your life. The fan and light will run for 30 min and shut off. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [September 11, 2014, 7:33pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/14 "2014-09-11T19:33:28Z")
> [@Emtar\_KronJonDerSohn](#): > > A separate switch will require a separate wire to be run. If the fan and light are in the same fixture, that may very well be. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [September 11, 2014, 8:08pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/15 "2014-09-11T20:08:11Z")
even if the fan and light were separate fixtures there still could be a single switched wire going to them. if there was two wires then a combo switch, two switches in one device space, as mentioned would work better. ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [September 11, 2014, 8:46pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/16 "2014-09-11T20:46:40Z")
Watch out for timer switches on a fan - that’s a motor, and they draw current differently than a bulb. Probably not a problem with the tiny motor in the fan; it would be an issue for the HVAC blower under the furnace. Another LOUD voice for separate switches. This isn’t (usually) a problem in a Master bed/bath suite, but: the switch near the door is the light; the fan is away from the door. Reason: when toilet training a kid, you want then to be able to see without the (potentially) scary fan noise. Never thought of that, did you dopers? ---
**Author:** ![Doug\_K](https://avatars.discourse-cdn.com/v4/letter/d/b5ac83/32.png) [@Doug\_K](https://boards.straightdope.com/u/Doug_K)\ **Post date:** [September 11, 2014, 8:52pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/17 "2014-09-11T20:52:18Z")
If I received a dollar for every bathroom in a private home that had no exhaust fan at all, and had to pay a dollar for every bathroom that did, I’d come out ahead. Not by much, but still ahead. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [September 11, 2014, 9:42pm UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/18 "2014-09-11T21:42:20Z")
> [@usedtobe](#): > > This isn’t (usually) a problem in a Master bed/bath suite, but: the switch near the door is the light; the fan is away from the door. Reason: when toilet training a kid, you want then to be able to see without the (potentially) scary fan noise. Never thought of that, did you dopers? You should be addressing cheap ass contractors, not Fellow 'Dopers. 🙂 ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [September 12, 2014, 4:06am UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/19 "2014-09-12T04:06:45Z")
> [@Doug\_K](#): > > If I received a dollar for every bathroom in a private home that had no exhaust fan at all, and had to pay a dollar for every bathroom that did, I’d come out ahead. Not by much, but still ahead. I actually bought a copy of the standard building code (back when I was messing with load-bearing walls, adding a bathroom, replacing/adding wiring. etc). The requirement was for EITHER: 1. An openable window (actually any section of exterior wall of sufficient size) 2. A mechanical exhaust fan. So, modify your bet - how many (professionally built) bathrooms had neither? An old-fashioned window which had both top and bottom panes openable would beat the tacky exhaust fans. The room which ended up as the master bath originally had an openable skylight. It was a constant leak of warm air, so I caulked the glass and covered the open/close bits. Code told me the room (which used to be the tub/lavy part of a split bathroom) now needed a fan. It got one. 2 switches, second is the fan, just like the hall bath. ---
**Author:** ![Doug\_K](https://avatars.discourse-cdn.com/v4/letter/d/b5ac83/32.png) [@Doug\_K](https://boards.straightdope.com/u/Doug_K)\ **Post date:** [September 12, 2014, 4:37am UTC](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200/20 "2014-09-12T04:37:44Z")
> [@usedtobe](#): > > I actually bought a copy of the standard building code (back when I was messing with load-bearing walls, adding a bathroom, replacing/adding wiring. etc). > > The requirement was for EITHER: > > 1. An openable window (actually any section of exterior wall of sufficient size) > > 2. A mechanical exhaust fan. > > So, modify your bet - how many (professionally built) bathrooms had neither? > > An old-fashioned window which had both top and bottom panes openable would beat the tacky exhaust fans. > > The room which ended up as the master bath originally had an openable skylight. It was a constant leak of warm air, so I caulked the glass and covered the open/close bits. Code told me the room (which used to be the tub/lavy part of a split bathroom) now needed a fan. It got one. 2 switches, second is the fan, just like the hall bath. Off the top of my head I can only think of four or five bathrooms with no windows I’ve ever seen, and two of them were in the same house. I’ve only seen one that had neither. That’s in houses, of course. Lots of apartments and motel/hotel bathrooms have no exterior walls. [Next page](https://boards.straightdope.com/t/am-i-causing-my-bathroom-to-rot/698200.md?page=2)