question: how to fight mold in windowless bathroom?


I've got a bathroom in a house which is getting mildy on the ceilling atop the shower.
The fan is on, but it doesn't seem to solve the problem.
Anyone know a strategy for preventing this?
Anything I can put on the walls and/or ceiling?
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wrote:

1 - Do you know if the fan is rated for the size of the room? I had to oversize my fan (2 X) to keep the mold off the ceiling. 2 - Do you know if the fan is actually venting the room? Perhaps it's blocked in some manner. 3 - There are additives that can be mxed in the paint to help retard mold growth.
P.S. I don't know where you live, but wherever the weather gets cold, almost all bathrooms are "windowless" from a ventilation perspective.
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Does your bathroom have a vent to allow easy air entrance?
the fan MUST run after the light goes off, so the room is well ventilated, a light timer is in order here
how big is the fan and where does it dump the air?
venting it into attic, either intentionally or accidently like lose fitting vent lines is a sure recipe for trouble
are you certain the fan is venting well and moving enough air.
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wrote:

I think it is sort of hearless to have mold and not let it see outside.
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Hold a piece of paper up near the fan to see if it is really pulling air. After twenty years of telling my daughters to turn on the fan when showering, I discovered that flapper that keeps outside air from coming in was stuck due to a sheet metal screw used to hold the vent on to it in the attic. Probably was this way when the house was built 30 years ago.

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What did your daughters say when you told them this?

No. I tightened that screw when I was there 15 years ago.

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On 31 Jan 2007 17:43:17 -0800, " snipped-for-privacy@rogers.com"

I a simular problem, spots of mildew on bathroom ceiling. Althought I have a window, but I don't open them.
This is what I did:
1. I changed out my two direction vent grill to a three direction one. Now it blows heat/ac into the bulk of the air space.
2. I tossed in more insulation over the bathroom, now ceiling doesn't get as cool for condensation.
3. I painted my ceiling with one of those anti-mold and mildew paints. I think it had a 5 year warrenty.
So far, for me, no mildew anymore.
tom @ www.Consolidated-Loans.info
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Sure. Fully enclose the shower, as in
http://www.sunfrost.com/efficient_shower.html
Nick
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I had an apartment like that once. It had no vent, but a window. When I took a shower, I stuck a fan in the window, specifically, one of these:
http://www.daviddarling.info/images/window_fan.jpg
It worked great!!!
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wrote:

Ventilate, ventilate, ventilate. IMO You won't fix a mould problem by spreading anything on the walls/ ceiling! We have same thing; bathroom in middle of house without window. We have been very careful to ensure that a working ventilation fan (to outside) never into an attic or blocked air space moves damp air (and smells) out of house. Since our vent faces towards the North Atlantic the fan sometimes has to be run for a while during a nor-easter! For that reason we have not connected the fan via a timer switch, preferring manual decision making. The fan uses very little electricity anyway. We could run it continuously for 24 hours for about three cents! During some 36 years since we built this house probably have repaired (not totally replaced) the fan motor some three or four times; also necessary to lubricate its motor's bearing once in a while. I keep a jar of motor bits having found that such small fan motors often have parts (bearings etc.) in common with old phono motors, fans from convection ovens etc. But a new motor or even a whole new fan assembly is not expensive. Especially compared to potential house damage and possible health risks of mould! Maybe by 40 years we'll have to replace the fan unit? they obviously last a long time. BTW our vent pipe/duct exiting through the cold attic then outside through the gable end does condense moisture within it. I was very happy that using rigid metal duct it was sloped downwards towards outside. In cold weather the moisture forms a small icicle drip (beard) on the vent outlet. Testament that the damp air is being exhausted from the bathroom. Inside; how quickly the 'steam' clears on the over sink mirror gives an indication how quickly the fan is doing its job. Again, ventilate. Our suggestion is, don't mess around with half solutions.
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