Can you vent bathroom fan through ceiling on to soffitts instead of roof

Builders do it. My house has 2 of 3 bathrooms vented through vinyl covered (alternating slotted) soffits.

Hi CC

You can't just dead end the vent into the soffit.

Instead, install a soffit vent termination kit (found at home depot)... see image below.

Another, better looking soffit termination kit can be found at Lowe's (click on link):

Shop IMPERIAL 4" and 6" Soffit Exhaust Vent at Lowes.com (http://www.lowes.com/pd_317949-85334-VTL0021_0__)

These kits can be used with dryer exhaust or with bathroom ventilation systems.

Mark

If installed as suggested her, it's all good. Do it right or don't do it at all!!

So my house, which was built in 1970 and added to in 1984, and which has slotted vinyl soffits done in 1984, was wrong to vent 2 bathroom fans just by butting the duct to a slotted part of the vinyl?
I was sort of skeptical at first, but haven't had any problems... the soffits are 2' deep.

If your soffit is also a vented soffit then you can't add a bathroom vent closer than 2 feet to the nearest soffit vent. Otherwise your moist bathroom air will be pulled into the attic space by the soffit vent. I have seen builders vent like you want but that does not always mean it is good.

Not what I want; what I got when I bought the house.
The bathroom I use is vented properly. The second bathroom isn't used, the fan doesn't work, and the room is going to be nuked soon. I appreciate the info on the soffit vent kit. That room is a garrison overhang. If air is sucked in, it's between the joists of the bathroom above it. The third is my roommate's, who usually takes baths, I think... I won't work above my head on a ladder. It will go on the list.
The dryer vent... someone had installed a 4" PVC elbow turned upwards as a vent. Go figure. I closed it off because I am moving the washer and dryer. I am an energy freak anyway. I dry clothes on a clothesline 90% of the time.