I noticed some moisture above the bathroom area.It seems to be more prominent around the sewer vent going out the roof.I have a ridge vent & soffit vents.I put a fan up there to help dry it out(moisture is bad).Any ideas what might be causing this?
Attic moisture???
- Thread starter Gizzy
- Start date
Kpaige
Well-known member
Ok this is my area of expertise!
They are correct above it is a temp difference in the pipe from inside to outside but here is what you do. Make sure it vents to the roof not the wall or soffit!
First the bath fan should be a fully insulated flexible pipe it should also have a J bend in it to trap any water that might not escape so it can evaporate.
Second- make sure you are running the bath fan for 15 minutes after you are done with a shower or bath I usually put them on a timer switch.
Third- Make sure you have the attic insulated properly this includes insulating the space at the ceiling where all pipes come through.
Last thing is to make sure that the fart fan vent going to the roof is connected to a fitting and sealed to it . This should attach right to the vent on the roof. Broan makes a small metal vent that has this fitting and it is perfect.
This will minimize your issue.
They are correct above it is a temp difference in the pipe from inside to outside but here is what you do. Make sure it vents to the roof not the wall or soffit!
First the bath fan should be a fully insulated flexible pipe it should also have a J bend in it to trap any water that might not escape so it can evaporate.
Second- make sure you are running the bath fan for 15 minutes after you are done with a shower or bath I usually put them on a timer switch.
Third- Make sure you have the attic insulated properly this includes insulating the space at the ceiling where all pipes come through.
Last thing is to make sure that the fart fan vent going to the roof is connected to a fitting and sealed to it . This should attach right to the vent on the roof. Broan makes a small metal vent that has this fitting and it is perfect.
This will minimize your issue.
Kpaige
Well-known member
Here is the roof set up but use an insulated hose
Here is the roof set up but use an insulated hose
That's exactly the vent I'm using,including the hose.The sewer pipe goes directly out the roof.
So if I understand you correctly I need to insulate the roof around the area around where the sewer pipe exits thru the roof. Thanks....I'm definitely going to try these suggestions.
Kpaige
Well-known member
No Not the roof the ceiling below to make sure all heat is kept in. Depending on the temp difference there can still be some frost. The goal is to minimize all heat/hot air escaping into the attic.
Problem lies in Science. Hot air holds moisture really cold air does not when that warm air hits the cold the moisture condenses very quickly and forms frost or ice. That is what is happening so you want the attic and pipes Etc in the attic to be the same temp as outside.
Problem lies in Science. Hot air holds moisture really cold air does not when that warm air hits the cold the moisture condenses very quickly and forms frost or ice. That is what is happening so you want the attic and pipes Etc in the attic to be the same temp as outside.
Kpaige
Well-known member
Well without seeing the vapor barrier, type of insulation and amount it is a guess but yes. Could in addition be making sure your attic has proper intake and exhaust venting.
You need to block air leakage that is going from the bathroom into the attic. Usually the bathroom fans are poorly made with leaky seams and random holes in them. The crack or gap around the fan where it is cut into the sheetrock ceiling is also a huge leak. To seal it completely means removing all the insulation above the fan, vac away all dust and debris, spray foam up all the holes and gaps. It is a lot of work and a pain in the ***. There will be a leak around the electrical box for the ceiling light as well.
This, or at least most likely. Even if your problem goes beyond this, this is very important. The warm moist air from showering if leaking into a cold area will condense and given this is a daily occurrence will never dry properly. Understanding the importance of controlling air leakage has come a long way in the past 5 years and many builders are not the ones doing the understanding.
To add, fiberglass insulation does not prevent movement of moisture or airflow. Think of it like a big furnace filter. When fiberglass insulation is enclosed on all sides as in a wall cavity, then it reduces natural air convection currents that would otherwise happen in the wall cavity.
My final solution to all these leaks was to take all the insulation out of my attic. Vacuum every sheetrock seam and ceiling penetration. Foamed it all. That really sucked. I had a huge pile of fiberglass insulation in my back yard for a few days.
The final straw that got me to do this hateful job was seeing my 3/4 attic floor plywood warped 180 degrees back onto itself during the winter. Moist air was coming through a hole for a romex wire out of the bathroom under the plywood.
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404 has it right...seal all air leaks into the attic.
Above my master bath the snow on the roof always seemed to melt faster...went up into the attic and found that fan was poorly sealed to the ceiling and the common wall between my 2 baths had a nice 1/2" by 8' long gap between the sheetrock at the top plate. Foamed and caulked all gaps I could find and now there is no more snow melting over my bath.
In a perfect world we would all vacuum out the insulation and spray foam the attic floor to seal it up like 404 did. ...but wow, that had to be a PITA!
Above my master bath the snow on the roof always seemed to melt faster...went up into the attic and found that fan was poorly sealed to the ceiling and the common wall between my 2 baths had a nice 1/2" by 8' long gap between the sheetrock at the top plate. Foamed and caulked all gaps I could find and now there is no more snow melting over my bath.
In a perfect world we would all vacuum out the insulation and spray foam the attic floor to seal it up like 404 did. ...but wow, that had to be a PITA!
Jazz1
Well-known member
I have seen this but possibly different circumstance. The house was on posts with furnace in crawlspace on dirt floor.. Open hatch to attic when its cold(-30) and snow storm! Frost throughout trusses. It was nasty!
The solution was laying down a heavy vapour barrier on dirt floor and sealing around posts as well as footings.
Good luck with yours.
The solution was laying down a heavy vapour barrier on dirt floor and sealing around posts as well as footings.
Good luck with yours.
It was. I ran a temporary pvc pipe from my dust collector that is in the cellar to the attic through a hole in the cellar/attic stairway.
The original insulation was rock wool and vermiculite poorly fitted. I had put fiberglass over that. So I saved the fiberglass and got rid of the old stuff before some one decides vermiculite or rock wool are deadly carcinogens needing expensive remediation. Blew in cellulose and put my fiberglass back over the cellulose. I had done a lot of soffit vent work over the years as well, now I am the only house I know of with never an ice dam, never ever.
UPDATE: I had a new roof put on last fall,still having moisture issues.The roofing company thinks it's an ice dam building up.The roof faces east.I have plenty of insulation,so they think it's sun hitting the east side of the roof is melting the snow up @ the peak & when it hits the soffit area it's refreezing.Inever thought about it...but it could be.Have any of you guys had to deal with ice dams?
Shawn S
Well-known member
I am not a roofer or an insulation installer. But it seems to me that if you have plenty of insulation and proper attic venting the sun is what will melt the snow. And since the sun is melting it, the roof temp will be the same at your soffit and it won't refreeze.
Kpaige
Well-known member
The key is ventilation. If you do not have proper air flow that pulls in from your soffits and out through the upper roof vents you can get ice dams. You need a gap of aprox 1” between your roof boards and your insulstion. And it needs to be like that everywhere otherwise that area will have issues.
All that being said if you just had a roof put on then they are not great roofers!!
I can put a roof on and get ice dams and still not have any leaks. It takes extreme detail but I did it for 30 yrs in Mn and on the worst possible inner city old houses!! Also a good roofer would have inspected for ventilation issues and corrected them when installing the roof.
It is also a comon scape goat to blame ice dams. On the rast side it would be rare. North and west are more common unless it is an extreme issue!
Post pics of your house and pics of the leak area that will help.
All that being said if you just had a roof put on then they are not great roofers!!
I can put a roof on and get ice dams and still not have any leaks. It takes extreme detail but I did it for 30 yrs in Mn and on the worst possible inner city old houses!! Also a good roofer would have inspected for ventilation issues and corrected them when installing the roof.
It is also a comon scape goat to blame ice dams. On the rast side it would be rare. North and west are more common unless it is an extreme issue!
Post pics of your house and pics of the leak area that will help.