Bathroom vents


I looked at a job today where the bathroom vent fans are exhausted directly into the attic. no evidence of mold or any other damage. roof is currently vented with gable vents and a power vent. no soffit vents. the house is 24 years old. Since there is no obvious damage already, do you think there is potential for a problem? Or does power vent suck that moisture right out?


It needs to be changed to vent to the outside. there are kits you can by at any lumber yard for this.


I see this every day in the attic.(bathroom vent)basically no problem. Real damage can cause boiler water ext.pipe or heaters pipe if have crack or it has been disunited during roofing project ,this is can delaminate, deform all plywood sheets + the power vent motor will refuse from an attic moisture


this occupant might be a bath tub person…
next one might be a shower user…then you’ll have problems…why wait…do it right, and take a preventive approach…kit only costs $10.00
for hose and vent . maybe 20. I see a lot that get
draped over the top plate into the soffit area, vented soffit or not. I like using the soffit vent kit rather tha a roof top unit. I recently learned that PVC dryer vent wall kits are not to code.


If you are the last one to touch the job and you could have done something to remedy the situation, you could be held responsible if anything develops in the future.

Why not have the home owner invest the $20.00 to $30.00 dollars to make sure it is done right, instead of cutting corners?



I wasn’t cutting corners, just gathering information. Am i getting defensive or does everyone seem to be on the righteous train lately?


until a couple years ago, i guess in this county it was perfectly fine to vent to the attic, not out of the attic. Now code states you have to vent out of the house some way. Many contractors have switched to venting the fart fan/ dryer vent out a soffit style vent out of the soffit with a furnace style box outlet,(you know the vents in your house for ac and heat) because the flappers on the fart fan style vent get stuck with a strong south wind and the any water/snow is welcome to come on in through the pipe or flex tubing.


even so, i have seen some new builds here that the tinners never even hooked the fan to a tube or anything. fart fan installed, vent installed in the roof, nothing inbetween. Then i got a call about a light in the bathroom leaking. Condensation from showers.


Yes, you are getting too defensive.

I was trying to keep you out of future liability from not acting on known code required work that could be concluded were obviously under your potential control.

If the home owner does not want to do it right, have them sign a waiver releasing you of any liability and that he has been advised accordingly.



i have worked in towns where everything had to brought up to code, if the value of the contract was more than 25% of the tax value of the property. in other words,
if a permit was issued, all the inspectors show up, even if the work has nothing to do with them…electrical, plumbing…ventilation in roof…now they even want to do a sheathing inspection…getting to be like FL I hear and I’m talking about Massachusetts.


Hi Ed,
For the cost it seems like a no brainer. I already have a signed contract so I’m not going to change the price, I’ll just do it.
Do you think its better to vent to the roof or soffit?


The roof, as long as the run of the hose is not too long.

Cheap freebies are nice, but you need to remember to be nice to you and your family too.

Some reports, especially from a heavy wind, allows the soffit route to push back the moisture back into the attic cavity.



Hi Shangle Nailer,

Keep asking your questions. You have to sort thru the responses to get your answers. Let the other ones go.

The hard part is to see that one time we may say the right answer. The next time we may talk out of our …

Like was said if the person takes baths, you do not need that much exhaust. If the person takes a short shower like me, you do not need alot of exhaust.

The exhust fan will help to offset the moisture. There is a lot of factors to consider. Codes do not cover the variables. That does not mean that you should not consider the varibles.

So keep asking your questions. That will make you the best roofer you can be. It will also make you a good living when you no longer want to do the bull work roofing. Eventually you will want to make a living with your brain instead of your back.


Here is a link to a recent poster on another forum who had weather infiltrate through his soffit vents. … ent-56440/



I was on a roof the other day… got a nasty whiff from a fart fan, and it almost knocked me off of a 8:12 hip.

not kidding. i think something died in the bathroom.

for the roofers sake… i say vent it into the attic. it can save lives. :wink: lol


Ed, thanks for the input. You think even though there’s no soffit vents throught the roof is better?
Reason I ask is cause I’ve seen things online about snow getting in those roof vents too. 6 of one half dozen I guess.


I recommend the bath fan be vented thru to a fixtured soffit vent, that being with a flap in line like a back flow preventer…Up here roof mounted vents and
ridge vents often get blocked in by snow for a while.
There has actually been some discussion about heat cables running down the ridge vent…Maybe a new invention…heated ridge vent…hmmmmmmmm.


The train arrived along time ago…

Some people put a quarter in the cup to help others, some for pity, others to show they are better.


[quote=“shangle nailer”]Ed, thanks for the input. You think even though there’s no soffit vents throught the roof is better?
Reason I ask is cause I’ve seen things online about snow getting in those roof vents too. 6 of one half dozen I guess.[/quote]

I guess it depends on the weather conditions from where you are located.

Some codes will not allow it in the soffits though.

Why is there NO ventilation at the soffits and did you propose any correction for that home owner?



I thought with gable vents and a power vent there should be enough air moving around in there. Perhaps I’m wrong. Hot air rises right?

I’m in central VA, fairly mild winters. A lot of icy rain and only a negligible amount of snow. This year we had a storm beginning of march 12", but that only happens about once every 5 years.