IRC cite on bathroom ventilation

[Marc]

Can anyone point me in the direction of the IRC cite that required a power vent in bathrooms where no window is installed?

Thanks

Marc

[Bill Kibbel]

It's in the building planning section (chapter 3). There is an exception to installing an operable window in a bathroom/toilet room if artificial light and mechanical ventilation are provided.

[Marc]

Thanks Bill.

The situation that confronted me today was a new construction with the master toilet in a closet that opened to the master bathroom. Mech ventilation was installed in the toilet closet but not where all the other plumbing fixtures were. No openable window there either.

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Toilet closet is off the photo to the left.

Never noticed that arrangement here before. It was an FHA Compliance inspection and I finally decided to just pass it.

Marc

[Charlie R]

I have run into that on new construction a couple of times. I thought another fan would be needed in the main bath area as the windows were fixed panel, but I was over ruled by the county inspector. At the time, the county inspector said you could turn the fan on and leave the toilet closet door open. I still recommended to the client to just install another fan, the client most likely did not listen to me.

[Jim Baird]

Marc I passed many like that as an AHJ. The toilet "closet" is not a different room, and some would say the fan is best placed there.

[kurt]

Yes, I see it all the time. It's compliant AFAIC. If the bathroom is a mega monstrosity with the car wash turbo shower arrangement, I might mention it to the customer and gauge their concern.

[Scottpat]

Only the water closet(room with the toilet) needs a vent fan. The logic as I understand is that water is always in the toilet and the humidity will always be higher.. so much for logic! Keep in mind that the IRC is the minimum requirement. When I find this type of setup, I always recommend installing a vent as an upgrade in the main part of the bathroom to help control humidity when the shower or tub are in use.

[Marc]

Yes, I see it all the time. It's compliant AFAIC. If the bathroom is a mega monstrosity with the car wash turbo shower arrangement, I might mention it to the customer and gauge their concern.

If such a shower exist, this is it. Builder calls it a walk-thru shower. Like a car-wash, it looks like a wall to wall walk-in closet but has an opening on each end. Shower system is midway and has glass panes on both sides so sunlight can pass through shower section to interior of bathroom. You enter thru one end, pass thru the shower section then walk out the other end. Good hi-rate production.

Marc

[Nolan Kienitz]

Common sense just doesn't apply it seems. Exhaust fan should be where the majority if the humidity is generated ... as well as the toilet closet.

Most newer construction down here has exhaust fans in both locations.

Guess we're lucky.

[kurt]

Common sense just doesn't apply it seems. Exhaust fan should be where the majority if the humidity is generated ... as well as the toilet closet.

Most newer construction down here has exhaust fans in both locations.

Guess we're lucky.

No, it's the Texas diet; lots of ventilation necessary to keep IAQ below toxic levels.

[kurt]

If such a shower exist, this is it. Builder calls it a walk-thru shower. Like a car-wash, it looks like a wall to wall walk-in closet but has an opening on each end. Shower system is midway and has glass panes on both sides so sunlight can pass through shower section to interior of bathroom. You enter thru one end, pass thru the shower section then walk out the other end. Good hi-rate production.

Marc

I'd probably give them an FYI about wanting more ventilation. It seems most builders continue to use those POS little dinks with about 35 cfm, and by the time it's ducted and static is taken into consideration, 8-10 cfm is about what you got.

If it was a nice inline Fantech or Panasonic cranking 80cfm+, or even a decent Broan giving 50cfm, it all might be OK. Depends on the cfm discharge.

[inspector57]

Around here since they each get separate fans. The way I read the code each toilet room and each bath room require mechanical ventilation.

M1506 - mechanical ventilation.

Common sense says if there is a door that separates the rooms it is a separate room with separate ventilation requirements. It becomes painfully obvious when the toilet room is a small closet with an 8' ceiling off of a 10x15' bathroom with 12' ceilings and double showers. No way that a fan in the toilet room will deal with the moisture from the shower in the other room nor will the fan in the bathroom deal with the odor from the toilet room.

[Erby]

C'mon Jim, since when does common sense rule in home building?

[kurt]

Really.

The nice setup is the Fantech inline rated for two inlets....run one duct to the WC and the other to the main bathroom. The whole shebang is up in the attic (or someplace) and you can barely hear it.

I've seen single fans work fine; it's more about CFM than two separate fans. Mother Nature takes care of moving moisture around pretty well, and if there's active exhaust, things seem to equal out satisfactorily.

Most of the fans I see, you could use 3 or 4 and they'd still not work worth a damn.

Also, having one of those nice Lutron switches with the timer buttons is nice.

[John Dirks Jr]

I also see it frequently in new construction. I recommend additional ventilation be installed. I also tell the clients to go back and look at the model home. Sometimes, the model home has a fan in both locations. I've had a few clients argue that point and win, resulting in the builder installing another fan for them.