[MurphyMan]

Hello Experts.

Bought a 30 y.o. house last winter and did extensive remodeling. Today we were dismayed to find a water stain adjoining the bathroom ceiling fan. :furious:

Last year I installed a Broan fan which attached to the existing aluminium flexible duct. You can see from the photo, where is a bit of a sag and I did feel a bit of water there.

The roof was replaced a couple of years ago and this is how they chose to connect the ducting. Nice, huh? Each bath routs to a Tee, then out to a covered vent. I never liked the setup, but chose not to address it. That side of the house faces the street and I was hoping to not blemish the clean roof by installing a vent.

I was wondering about installing a sideways vent, but you can see from the third photo that I would probably have to have a down-turn right at the wall.

So folks, would you have any suggestions? First, I would like to know the best practices for installing a bathroom vent. Is the flexible foil standard?

Second, drifting away from best practices, :whistling2: do you see any other way to handle this, so I don't have to cut a hole in the front of the roof?

Thank you very much.

Murph.

 

[jagans]

why don't you pipe it with rigid PVC right in the attic floor, under insulation and out the soffit? You are getting condensation in the attic, and you have run that flex duct way too far, and with dips in it to pond water.

 

[MurphyMan]

why don't you pipe it with rigid PVC right in the attic floor, under insulation and out the soffit? You are getting condensation in the attic, and you have run that flex duct way too far, and with dips in it to pond water.

Won't that cause the warm moist exhaust air to be sucked up into the soffit vents?

 

[MurphyMan]

Here is a photo of the soffit. The photo is taken, just outside of the entryway vestibule.

It's hard to see, but the soffit is not parallel to the ground. It is plywood and has the same slant as the roof line, forming kind of an umbrella effect, I think. Actually, I think the existing soffit vents aren't big enough, but that is another issue, I guess.

 

[jagans]

Well, I have a ranch, and mine is vented like that and I have never had a problem, but you sure dont want to dump poopie smelling air out into your entrance foyer. Can you go the other way?

You are correct re soffit venting. You don't have enough to make any difference at all.

Nice house though!

Forgive my saying so, but have you had problems with ice damming? The sheathing near the eaves looks really discolored. Im pretty sure you need to fix your eaves venting on this home. I dont get the half baked wood blocking of the edges of the sheathing either. Just saying.

 

[MurphyMan]

Well, I have a ranch, and mine is vented like that and I have never had a problem, but you sure dont want to dump poopie smelling air out into your entrance foyer. Can you go the other way?

You are correct re soffit venting. You don't have enough to make any difference at all.

Nice house though!

Forgive my saying so, but have you had problems with ice damming? The sheathing near the eaves looks really discolored. Im pretty sure you need to fix your eaves venting on this home.

Thanks :thumbup1: - we like the new place. We moved from a little ranch house right next to busy train tracks. We are in southern Illinois and typically only get about 6" of snow for the whole winter. Having said that, we got about 12" just after Christmas. Last year we only had about 1/2" total.

I saw somewhere the attic vent should be: area of the attic divided by 150. Then split the result between the ridge vent and the soffit vents. The soffit should be equal to, or larger, than the ridge vent. Does this sound correct?

I haven't measured the attic yet. The spacing for the ridge vent only appears to be about 1" on either side to the center beam. Last summer, during the heat wave, my digital thermometer was reading 140 F in the attic, and I suspect that was the upper limit for the device. I had one roofing guy come out and he glanced at the vents and said they were adequate. Of course, he wasn't there when it was 140 degrees in there.

 

[MurphyMan]

Forgive my saying so, but have you had problems with ice damming? The sheathing near the eaves looks really discolored. Im pretty sure you need to fix your eaves venting on this home. I dont get the half baked wood blocking of the edges of the sheathing either. Just saying.

I have had several people comment on the half-baked wood blocking. We had a huge storm in our area about 4 years ago and every other home got a new roof. I imagine that blocking was done at that time.

Yes, it's a nice house, but there are several areas were the builder cut corners. Code enforcement isn't real strong in a lot of these parts.

 

[joecaption]

There's not even close to enough venting in those soffits.

 

[jagans]

The real fact about eaves venting is that you need all that you can get. I always recommend throwing the calculator in the lake and go continuous vented eaves. The fact is that eaves venting gets about 60 % clogged with insects, pollen, atmospheric dirt and misplaced insulation very fast, and all those wonderful calculations go to aunt Marys House. You need continuous vented soffit and ridge venting, and baffles at the eaves. What you have is simply inadequate, and should have been picked up during your home inspection, if you had one. The blocking should have been picked up too, IMO.

 

[Gary in WA]

I'd go out the gable end, first, second out the roof, and last the soffit. You don't want/need bathroom moist air in the attic space. Definitely change the ducting to straight pipe as said. Try to use 45* elbows rather than 90's. Foil tape the joints, including the individual elbow ones, support with metal hangers. INSULATE per code (or more) when passing through an unconditioned space (attic) to prevent/diminish condensation. Go one size up when using flex;http://rockwallcontrols.com/Residential/?tag=air-ducting Best not to use it at all for air flow. With all the folds (supposed to be fully stretched when used) to catch extra condensation and restricted air flow, and easy to restrict diameter with sags, sharp turns, supports required per code; I'm surprised it has a market... what is the distance run to the gable?

Gary

 

[jagans]

Gary is probably correct here, maybe. A bathroom (My Bathrooms Anyway) do not generally produce the level of condensation that would be cause for concern to me. It is not like a gas fired appliance wherein constant steam and condensate can be expected. I have had no problems at all in MD, your mileage may differ.

 

[Gary in WA]

Maybe, lol. Family of four with 10 minute showers = up to a pint of moisture per day; http://www.buildingscience.com/docu...ir-leaks-how-they-waste-energy-and-rot-houses

Clear up to 2003, code didn't require bathroom vent to terminate outdoors (someone correct me if wrong); http://publicecodes.cyberregs.com/icod/irc/2003/icod_irc_2003_15_par011.htm

2006 had to exhaust bath fans outside, not into an attic as we see plenty of members with moisture problems from that; http://publicecodes.cyberregs.com/icod/irc/2006f2/icod_irc_2006f2_15_sec001.htm

Important enough to amend in the IRC (from moisture problems, not smell), I feel it's important enough to add in an answer. I hope this clears it up some for you.

Gary
PS are you opening a window also? Are you taking cold showers/baths? Are you taking -2 minute showers?