insulating a windowless bathroom

[giddonah]

I'm cutting a bathroom in half and it will not have a window. I'm planning on putting in a decent vent (I have the NYS plumbing code, but can't find anything about the required size). Anyway, I'm insulating the walls. I've seen Rich say something about faced batts in relation to bathrooms, and some other site say something about unfaced batts and bathrooms, but I'm not clear on this yet. My partner in crime says to go with the faced batts and any moisture will be absorbed by the very dry house (still talking about my 100yr old project here).

So, an interior bathroom, faced or unfaced?

[Rich]

Either will work.. but you'll need a vapor barrier in either case. So if unfaced batts are used you'll want a vapor barrier.

Sizing of vent doesn't really matter - but I think it does require a certain amount of air changes per hour.. look for air changes per hour or ACH in the code - it might have a chart for types of rooms.

[Tom R]

You'll find the necessary info on the exhaust fan packaging.

[giddonah]

Thanks guys. I'll go with faced, and there's nothing in the code about air change either. I'm thinking it's in the HVAC code, which I don't have. One more thing to get I guess. I'm sure any vent I get will be sufficient (or at least a decent sized vent).

I have some awesome ideas for this bathroom. It's going to be a little small, but pretty slick. I'll get some pictures when it's done.

[mfinley919]

Take the width*length*heigth of the bathroom then divide by 7.5 for the CFM (cubic feet per minute) then match that number to the exhaust fan you buy.

[giddonah]

thanks finley.

[Tom R]

Yeah, mfinley's method works, - - I believe that would give you around 8 air changes per hour, - - and I also believe that local codes can vary from anywhere between 5 to 8 changes per hour, - - depending where you live. A 'minimum' code might be 5, - - but 8 would give you optimal results.

Another method is Length X Width X 1.07 (based on an 8' ceiling height).