Originally Posted By: rray This post was automatically imported from our archived forum.
I got asked a question today for which I really had no answer although I seem to have made up some good B.S.
A bathroom vent flue was disconnected in the attic, venting moist bathroom air directly into the attic. Why is this bad? Just because? Just because a code somewhere says so?
As my Client pointed out to me, with the two gable vents, the four turbine vents, and all the soffit vents, what's the difference between outside, moist, night time, mountain air getting into the attic every day of the year for eight hours a night and a little moisture from a 20-minute shower getting into the attic twice a day?
Originally Posted By: dvalley This post was automatically imported from our archived forum.
Russel,
A simple little bathroom vent seems to be no big deal, but it is. In your present situation with all those roof vents, it probably isn't a big deal now. But I'll always tell my client (and note in my report) that this vent should be the vented to the outside air or at least in the soffit area if house is equipped with a soffit vent.
Most of the time I see these vents, there appears to be no structural damage. But there are those few vents in attics that cause discoloring and blackening of the sheathing and insulation. Which is moisture. A hot shower causes quite a bit of moisture to rise through the vent and into the attic area. This, in turn, causes all structural elements above this point to retain the moisture. Causing damage in most cases.
Whether damage has occurred or not, I always make it a point to let my client know that this needs to be corrected.
Originally Posted By: nlewis This post was automatically imported from our archived forum.
Russel,
In your part of the country, it might not make a difference. In the East, moisture collects on the North side of the roof sheathing during the winter months.
I see bath fans discharged into the attic all of the time with no obvious problems because of sufficient roof venting. In my attic, two bathroom fans vented into the attic for many years before I got around to discharging them outside. It was no problem because of plenty of roof/attic vents.
Originally Posted By: rmeyers This post was automatically imported from our archived forum.
Russel,
It is common in this area to see the bath vent pipes extended to, and terminated next to a roof or gable vent. As Dave stated, the moisture on wood surfaces often leads to mildew/mold and possibly rot.
Our cold weather, as Neil's in Mass., and high humidity levels contribute to condensation problems in the attic. The cold roof surfaces will condense moisture from a variety of sources in the house. Vapor from the bath vents, dryer vents, too high humidifier settings, excessive plants, cooking and inadequate vapor barriers in crawl spaces can all contribute to condensation problems in poorly vented attics.
The condensation within un-insulated exhaust fan ducting in the attic can also back-flow into or around fans or fixtures appearing to be "roof or flashing leaks". Sometimes, what appears to be leaks in the outer shell of the house are actually moisture problems created from within.
There is a publication in the NACHI library, "Condensation and Related Moisture Problems in the Home", which you may find informative.
In our extreme climates, insulation, proper vapor barriers and adequate ventilation are critical and all need to be properly integrated.
Originally Posted By: rsummers This post was automatically imported from our archived forum.
Up here in Butte county CA you are allowed to vent bath fans into the attic. The only area that its not permitted is with in city limits (different BLD dept). I always state the fact that they should vent to the outside as a comment not a defect.
Originally Posted By: rpalac This post was automatically imported from our archived forum.
I find all the comments to be percise in the same realm…moisture in the attic.
We all know that this creates a problem because the water vapor will eventually condesate on the underside of the roof sheathing causing rot.
The biggest item I find is the tempature differential will cause that hot moist air that is purely saturated to drop its water at a very high rate. It might as well be raining in there.
If you take a shower and raise the temparure of the air. The air has the ability to hold a very, very high amount of water. SATURATED As the air cools it can no longer hold the water vapor and bingo, it's now in the atttic.
The regions acroos the US have different tempature year round. But saturated air will still cool and loose water. Expecially if you exchange air for a hal;f hour shower with the water scolding hot.
Originally Posted By: anatol polillo This post was automatically imported from our archived forum.
Recently I did an inspection for a buyer who was dealing with the builder. They had been in the house since Thanksgiving. All 3 bathrooms were venting to the soffits. I could only get to one of the vents in the attic. In less than 2 months, there was already discoloration on the wood around the soffits where the vents terminated. I recommended they be vented to the roof. By the way there was no ridge vent, only soffits all the way around. I could go on…
Originally Posted By: jrabanus This post was automatically imported from our archived forum.
Speaking of shower vents, I see alot of showers in basements, and I always advise people to vent that to the outside. However, in most cases that is not possible.
I was wondering what everyones opinion is on showers in basements?
