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Is this vent pipe installed incorrectly and the source of my problems?

mnestroy Member Posts: 9

I have discovered a very high level of moisture in my attic and as a result the insulation a near the gable end is very damp and i now have mold all in my attic.

I suspect that the Furnace vent that was installed on the lower attic/roof which is placed approximately 15inches away from the gable wall/siding of the 2nd story attic is the source of the moisture/mold.

I have witnessed hot steam/humid air venting out of this pipe and due to its proximity of the upper attic and siding I suspect this is how the moisture is coming in. I have gone out there on dry days and the siding was dripping water like it had just rained.

As you can see form the attached photos the vent is placed very close. The second photo is from the inside of the upper attic on the opposite side of that wall. You can see the wall itself is very damp and the insulation in that area is a different color/damp.

Can anyone tell me if

1. They believe this is in deed the source of moisture and not poor attic venting? I only moisture build up on this gable wall and the insulation elsewhere is dry.

2. Is this vent placement against code? I am not an HVAK installer just a common home owner but I have done several searches and found references to NFPA 54 stating "“ that the flue gases are directed toward brickwork, siding, or otherconstruction, in such a manner thatmay cause damage from heat orcondensate from the flue gases”

3. if this was installed incorrectly is the company that did the work legally liable for correcting the problem and fixing the damage caused? I used a very large company and had ever permit pulled and passed inspection by the city.



  • Tim McElwain
    Tim McElwain Member Posts: 4,480
    What is the Make and

    Model number of the furnace? The Installation and Operations manual will give a detailed breakdown of the correct venting for this unit. If it is a Category II, III or IV appliance then NFPA 54 does not cover the venting as it is classified as special venting and is installed in accordance with manufacturers instructions only.

    If you look inside the unit for the rating plate it will state which category. Does it have a fan on the venting system at the furnace, not the system fan that blows heat through the house but one for the venting system?
  • Paul48
    Paul48 Member Posts: 4,470
    Very Simply

    If you have moisture damage, and or mold, behind the siding, then there is a chance it comes from that exhaust.If the sheeting behind the siding is fine, chances are it is caused by poor ventilation in the attic space. Is that wall on the sunny side of the house?Let a mold remediation specialist clean that mess. Certain molds can put you in the hospital, or grave.They can also help with determining the cause.Stay out of that space unless you are wearing a respirator designed for mold, not a dust mask.
  • bill_105
    bill_105 Member Posts: 429
    Last time I checked...

    the book, it said, "no vent termination less then 8 feet from a vertical wall". I could never figure that out. How could a wall be horizontal? Oh, the never ending mysteries!
  • icesailor
    icesailor Member Posts: 7,265

    If you didn't specifically call it "A Vertical Wall:, and just called it "A Wall", some legal wag would argue that the rule wasn't specific enough and the vent was in  compliance as the rule was written.
  • mnestroy
    mnestroy Member Posts: 9
    Make and Model

    The make and model is a Lennox G61MPV-36B-071

    The manual says "The G61MPV category IV gas furance is with a two-stage, variable speed intergrated control...."

    It also says "In order to ensure proper unitoperation in non-direct vent applications, combustion and ventilation air supply must be provided accorded to the current Nation Fuel Gas Code or CSA-B149"

    "In both Non-Direct Vent and Direct Vent applications, the vent termination is limited by local building codes. In the absence of local codes, refer to the current National Fuel gas Code ANSI Z223-1/NFPA 54 IN USA..."
  • VictoriaEnergy
    VictoriaEnergy Member Posts: 126
    edited February 2012
    Maybe, but have a closer look

    You should have the vent moved if the wall stays wet, but that's not nesesairly what's causing the problem in your attic.

    The siding should be able to stay wet for long periods of time without harming the building.  The building paper under the siding is supposed to be providing the barrier keeping water from penetrating the wall.  See the attached picture.  Note the flashing they show at the bottom .  On the junction between your lower roof and the wall you should be able to see about 2" of flashing, but your siding is coming right down and touching the roof.  So that tight junction could be packed with dirt that could be letting water wick up into the sheathing behind the flashing.  I mention this because in your picture of the roof the siding looks like it has mildew lower down the roof.

    There could be other problems as well.  Like if you have constant warm air from the house leaking into the attic.  Humid air from the house looses it's capacity to hold water as it cools down so it can condense in the attic.  So have a look at draft proofing in the attic, leaking bath fan vents, If you have added insulation to the attic both the size and qty of vents near the peak and at the soffits (as well, the 'trays' between the soffit and attic should not be clogged with blown insulation).

    Have you added insulation to you attic in the last few years?  I've seen some issues with mold in attics as a result of just adding insulation and not considering draft proofing, and attic venting. The good news is you don't really need to remove mold from attics since you are not normally exposed to the air in your attic.  Just stop what ever is making it wet enough for it to grow. 

    It's now a common practice to install gas appliances with side wall venting.  I've had very few issues (and never with a roof terminal location), but it does sometimes happen.  Usually due to the prevailing gentle breezes that may push the exhaust back towards the house.  I'd suggest asking the company to have a look at the instructions for the furnace and see if they can add more elbows and length the the vent system.  If they can,  have them move the vent further away from the wall by offsetting the vent where its inside the lower attic.

    If it's not too late, I'd skip the liability/legal part of the discussion.  If the installing company becomes concerned you are going to sue them, they may not want to move the vent since it could be taken as an admission they did something wrong.  
    Home Owners Please Note:

    You are receiving advice from some very skilled pros completely free of charge. One of the reasons I participate is to sharpen my own troubleshooting skills. So; did we get it right? I would be grateful if you extend this courtesy back by posting the final outcome of the issue you are inquiring about. Thanks
  • Henry
    Henry Member Posts: 988

    NFPA54 still applies when using special venting. You still must respect the clearances specified! Here that termination would be tagged!

    We have had many discussions in main and venting sub-committee about special vent terminations. Our code B149.1 is more specific about terminations.

    I am sure that if you look in your I&O manual that the installer is supposed to leave, it shows termination instructions.
  • Henry
    Henry Member Posts: 988
    Attic ventilation

    Looking at the picture, I don't see any attic ventilation. This may be your culprit.
  • mnestroy
    mnestroy Member Posts: 9


    Thank you for al your help.

    I contacted the city inspector who inspected/passed this  inspection and he says they have no codes that come into play here.

    As far as the attic,  when we purchased the house there was mold in the attic and htey spent almost 4k having it fixed. while the photos may not show it, every single  sofit vent is wide open. while it is not a continous soffit from the attic you can see ample day light from between each joist.  Also every joist has insulation sleds in so that air can flow.  I also have 5 8inch mushroom vents.

    I may still be willing to accept that the vent is not the source of the problem, but why is it that i only see signs of water on this gable end where the vent is?  the insulation is wet and so is that wall, no other walls or insulation is damp anywhere else in attic.

    I checked the flashing and while the shingles are pretty tight the metal corner is very clean and not blocked.

    Here are some more photos and a video I just took of the vent blasting out steam.  Its hard to see but at one point the wind was just right and the steam blew towards the street and at which point it could very well get sucked into the soffit vent.

    If you click on this link you can view the video which shows much more than the photos¤t=P1040098.mp4
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,195
    The flashing along the gable

    May be leaking. If it is even there.I am referring to the area where the lower roof meets the wall.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Ironman
    Ironman Member Posts: 6,562
    edited February 2012
    How About...

    Bath exhaust fans or dryer exhaust? Are any of these exhausting into the attic? If so, that may be part or all of your problem. These must be terminated outside, but quite often they're not.

    Also, look for a plumbing vent that wasn't carried through the roof.

    I agree that you probably need more ventilation in your roof. Does it have a ridge vent?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • VictoriaEnergy
    VictoriaEnergy Member Posts: 126
    edited February 2012
    Changing the vent location

    The video does show the gently prevailing air movement in the area pushing the exhaust towards the wall.

    What is in the room on the upper level near the vent?

    I'm thinking maybe the vent could be run from the lower attic sideways into the room (hopefully a closet) below the problem attic and then up and out the the upper roof.

    If you have a look at the installation instructions, they usually have an allowable combination of: Furnace size, vent length, vent size, and number of elbows allowed.  So by example; you could work out that your 80 000 BTU furnace with 2" vent can have 50' of vent length with 4 of the 90 degree elbows, or 35' length with 6 elbows.  Measure carefully every single inch of  existing vent length and count elbows along the way.  You may find it necessary switch it to 3" vent to allow a longer total length and more elbows.  Yes, it is a bit convoluted.  Have the company who installed the furnace do this, or, hire another qualified dealer for the same brand of furnace you have do it.
    Home Owners Please Note:

    You are receiving advice from some very skilled pros completely free of charge. One of the reasons I participate is to sharpen my own troubleshooting skills. So; did we get it right? I would be grateful if you extend this courtesy back by posting the final outcome of the issue you are inquiring about. Thanks
  • icesailor
    icesailor Member Posts: 7,265
    Mold and venting:

    These mold problems can be very hard to DX. And I think that your problems may be more involved that the mold remediation people were knowledgeable about.

    I can't tell from the pictures which way the roofs are oriented. But a North facing roof may not have any sun fall on it for most of the day, and moisture migrating through the insulation will stick to the underside of the cold plywood.  Sometimes, you will see the first 4' of plywood, all black on the underside because of the amount of moisture and heat that comes through the insulation. After 4', the warm air and moisture is dissipated and cooled enough.

    The mildew stain on the siding may be from unburned ethanol vapor mixed with the moisture in the air. If that is on a shady wall, and you don't have any mildew on a full sun wall, that could be what it is. The UV radiation from the sun kills the mildew plant. Google it.
  • mnestroy
    mnestroy Member Posts: 9

    The front of the house faces north,  the vent  is on the north side of the house/roof.

    The rooms that are adjacent to that wall (right around the corner from the vent) to the left is first a starcase going up to the second story, then a closet where the starcrase ceiling is. (that close is in a bedroom jus to to top of the stairs)

    As you go up the stairs this puts you in a hallways which is dead center of the house and pretty much dead center of the gagle.

    On the other side of the house Up the Stairs, past hallway, is a bathroom, and then before the houseside wall is another closet.

    The only vents in the attic are for the upstairs bath and the plumbing stack, both are properly vented outside.

    The house had mold 6yrs ago when we bough it and the previous owner spent almost 4k having a modl remediation company "fix the problem" well that company is no longer in business and that is why I am reluctant to spend another 4k to fix the mold again...

    Every soffit  has sleds installed in them and there is a lot of visible light from each soffit vent.  I do not have a ridge vent but do have 4 8inch mushroom vents.

    One thing that i just noticed is i can see daylight at the very top of the ridge where the ridge meets the gable wall.  I'm not sure if this is by design?  I supposed this moisture could be getting drawn in from that point.

    Should i take a photo of what i'm referring to?
  • icesailor
    icesailor Member Posts: 7,265
    Mold and venting:

    I don't think that the gas vent has anything major to do with your mold problem. Good luck finding someone who truly understands what you have going on. It isn't easy to explain in writing here. Just to say, you have another problem. The vent terminal is just throwing you off.

    Where are you located in the country?
  • mnestroy
    mnestroy Member Posts: 9
    One more Inspection


    I know you said the problem is not this vent however then the probem is something is with that wall.

    I went into the attic this afternoon and inspeceted the opposite gable and it was dry as can be.  I headed over to the vent side and sure enough the wall was wet, studs where wet, insulation touching wall/studs wet.

    As I began pulling back the blown in insulation I discovered a hole in the wall that had formed due to the water.

    How do I describe this wall.... its basically a 1/4th inch partical board, as I looked through this hole I saw the backside of the siding.... no house wrap nothing.  It had been explained to me that since I have aliumnium siding and the age of the house a house wrap wasn't standard.

    So, while you think the constant blasting of steam against this wall has no effects please tell me what could be the source of all this water on this wall if not the vent?  Notice the opening at the ridge where air can enter, or the nail heads with water drops hanging from them, or the droplets formed on the ridge line.

    I dont know how houses are built, so I dont know what matrial is supposed to be used, but a thin sheet of partical board between the indoor and the siding doesn't sound right. OH yah, this "cardboard wall" is bowing inward almost past the distance of the 2x4's holding it.

    I had attempted to tape up where it seemed water was leeking in but as you can see that didnt help as water still found its way in...
  • icesailor
    icesailor Member Posts: 7,265

    You have a mess. But it isn't from the furnace exhaust vent. That mold is at the floor. It is caused by warmth migrating upwards from the ceiling below. As the cold, uninsulated wall, allows cold temperatures to radiate through the wall, it cools the warm moisture laden air against the wall and the cooler air drops through convection. The warmer, moisture laden air drops through convection and as the temperature drops, and the dew point hits the temperature, the moisture condenses at the bottom of the wall. Heat flows to cold, dampness flows to dryness. The cooler air outside will hold less moisture than the warm air inside. The heat flows to the cold. When the warmer air, inside, flows into the colder wall, the moisture drops out on the cold surface.

    You need power ventilation in the attic to try to control the problem. That blown in insulation doesn't help. As a third world remedy, you need an exhaust fan like a Fantec with a few inlets run in flex duct, and one over to the mildew area. Run the fan with a humidistat. The fan will lower the humidity by drawing outside, cooler air which has less moisture in it.

    If you watch HGTV's series, "Holmes On Homes", they deal with this mildew/moisture problem all the time. Spray foam seems to be the most effective solution. It seems that the farther North you go, the worse the problem becomes. But that cardboard wall surface may need to go. Its complicated.
  • mnestroy
    mnestroy Member Posts: 9
    Who do i call?

    Okay, who do I call?

    A roofer, mold specialist, insulation specialist?

    The house had mold when we bought it and it cost the previoius owner 4k, so my faith in Mold Remediation isn't that high.

    Is this something that would be covered under homeowner insurance?  I have been told "mold" in general is not, but a roofer told me that there is signs of ice damning damage and that may be covered.
  • icesailor
    icesailor Member Posts: 7,265

    I can't tell you who to call. I know that this mold issue is a continuing subject.

    If you can find a way to watch the HGTV series "Holmes On Homes", it seems that almost every home he gets into has a mold problem. He is in Canada in the Toronto with the cold temperature swings. Your photos are a poster ad for what I have seen on his show. These Canadian mold remediation specialist may be at the cutting edge of evolution on mold control. One thing I have seen them do on almost every problem job is rip out the bad stuff like the cardboard walls and use spray foam. They seem to spray foam everything. That way, there is a thermal barrier between the inside and the outside. One thing they have said is to NEVER use bleach on the mold. Once, they used dry ice (Carbon Dioxide) to kill and remove the mold, Other times, they sand and vacuum it. But it is more complicated than I ever imagined.
  • VictoriaEnergy
    VictoriaEnergy Member Posts: 126
    I've slowly changed my mind on this one

    I think there is a strong likely-hood the moisture is coming from the vent.

    Everyone in the heating business has dealt with issues perceived to be caused by our work in their house.  The nature of these claims are widely varied and often border on bazaar.  I had a customer once who phoned the day after we did an install in his house and was quite upset because his car wouldn't start and wanted to know what we did to it (we walked by it several times!).  Invariably, our work seldom has anything to do with the problem.  So I admit I started off being a bit skeptical when I read your initial post.

    With no building paper under the siding (in my area its always present, even in old homes), you can see daylight getting in near the junction of the upper wall and roof, and the prevailing air movement appears to push the exhaust towards the wall.  It's easy to see how at least some exhaust is getting into the attic.

    As far as remediation.  I think you need to get rid of the moisture, to stop the mold and rot.  After that; why go to the expense of removing it when its in the attic?  It'd be different if the mold was in a living area of the house.   In most houses leakage between the habitable part of the house and the attic is one way only from the house int the attic (google "stack effect").  You most likely won't be exposed to the mold spoors.  So why have it removed when it will just go dormant and eventually die off from low humidity and high temps in the summer?
    Home Owners Please Note:

    You are receiving advice from some very skilled pros completely free of charge. One of the reasons I participate is to sharpen my own troubleshooting skills. So; did we get it right? I would be grateful if you extend this courtesy back by posting the final outcome of the issue you are inquiring about. Thanks
  • icesailor
    icesailor Member Posts: 7,265
    Mold in attic:

    Put a CO detector in the attic. If it goes off, it is coming in.

    Where the mold is the worst, is at the bottom of the wall. Hot air rises, cold air falls.

    In my career, I worked on three houses that had hydronic radiant in the ceilings. I was in the attic of one and noticed that the first 4' sheet of roof plywood was black along the whole length of the top plate. I wondered why and realized that although the ceiling was covered with insulation, heat was migrating through the insulation and the moisture and heat was sticking to the cold plywood in the winter. After the 4', the plywood was normal. I noticed the same thing in the other houses with radiant. I see it on the inside of roof sheathings that are on the North side of roofs where the winter sun doesn't heat the roof. I've also noticed the phenomenon in other wood roofed houses.

    You have no idea how much moisture gravitates through ceilings into attics. If you have a cold spot, the moisture will condense on the cold surface and mold can grow.

    If I were looking for a solution, I would make note of the vent outside and then eliminate all possibilities before deciding that the vent was at fault. The mold remediation company already screwed up in their DX of the problem.

    That ridge looks like it has some form of vent to let the heat out of the attic in the summer. If you pot pot ventilators in the attic, and turn them on, and don't have places for fresh air to come in, you will only create an air loop there the pot fan sucks air from outside through the roof vent and exhausts it out the pot vent. The warm, moist air below doesn't get circulated out  The new air from outside has moisture. If you have a pot vent in the roof, and a ridge vent, you could be sucking exhaust into the attic. But you need to prove it.

    You still haven't said where this building is. It seems to be a really bad problem the colder the climate is as seen by me on Holmes On Homes on HGTV.
  • mnestroy
    mnestroy Member Posts: 9

    I appoligize for not answering your ealier question about my location, I had over looked it. (my head is spinning)

    I live about 25 Miles west of Chicago.

    I had a roofer actually over today, he was a little confused about that ridge... while it looks metal it is a very thin pice of wood.  There is no ridge vent.

    One other thing that he noted as odd, is the house was built in 85 and the 2nd story (not the garage where vent is) has 3 layers of shingles... (garage only has 2)

    1. Having 3 layers of shingles is not code (here atleast)

    2. Why would a home need 3 layers of shingles in 27years? (we bought the house 6years ago so, I dont know when the 3rd layer was installed, but before we moved in so make that 3 layers in 21years)
  • icesailor
    icesailor Member Posts: 7,265
    Roof Shingles:

    The three layers of shingles are definitely not to any code. Nor allowed by homeowners insurance I believe. The weight on the rafter/roof system is way over the limit. Whomever installed that last layer of shingles knew he was doing something illegal and you can be sure that if there is an Inspectional Services department in your town, they have no record of who did the re-roof. If you got a wet, piling snow and then it rained, the roof could collapse. Standard shingles, laid ay 5" to the weather weigh 235# per SqFt. 3 layers weigh over 700# per 100 SqFt.

    That said, the reason that there are three layers of shingles on the garage and not on the rest of the roofs is because of the on-going moisture problem. I know that the area around Chicago and the Midwest can get cold enough to freeze the nipples off a witch. And so hot in the summer to melt one (the witch). Those temperature swings will cause massive frost build-up inside because all those layers of shingles act as insulation. In the hot summers when the sun is high in the sky, the roof will "cook" and never cool down. The excessive heat cooks the asphalt and causes the shingles to prematurely curl and shed their grit. Especially fiberglass shingles as opposed to felt ones. Most  standard paper roofs are at least 15 years. I would guess that the first one went less than ten. The previous owner probably changed the first to the second, then when he went to sell, the second roof had already failed. When he wanted to sell the house, the garage roof looked like hell and he had the whole house re-done. If he just did the garage, it would be obvious. From the timeline, the third roof woul;d have been a warranty but the claim would have been denied because of excessive heat build up under the shingles. And the second roof applied over a first one unly lasts less than half the life of the first. And memory may serve me that a new roof applied over an old roof has no replacement warranty

    What happens to asphalt shingles when they are "cooked" in the sun is that certain "products" that are in the asphalt when new are boiled out of the asphalt over time. The hotter the roof, the faster it happens. The newer shingles will be more pliable than the single layer underneath. If you can pry up the starter course on the garage without breaking them, and get to a layer underneath, you can snap a corner off like a piece of well done toast.

    In my opinion, that isn't worth much, the problem has been there since the house was built. Everything done to try to fix the problem has made it worse.

    If you find someone with a thermal imaging camera, you would be stunned to see what it shows. In Massachusetts, we have been way ahead of this problem because our winters are like your in the western part of the state. I'll bet on a hot summer day, that space gets to over 150 degrees. We require ridge vents. Take off the cap and install either a pubic hair strip of a plastic corrugated strip that is bent over the ridge after you cut the top if the sheathing to let the air out. Then, you need soffit vents or a slot behind the facia. They also have a starter strip for shingles that lets air in. The fan pot vent probably only runs in the summer to try to cool off the inside but it doesn't get hot enough to make it run in the winter.

    I suggest that you look into what I say. If they don't come with solutions like I have suggested, they don't know what they are talking about so look elsewhere. But rip the three layers off and get it back to one. The hard part is for the roofer to tie the new single layer roof into the old two layer roof.

    The vent may have a slight influence but the roof venting system is really at fault.

  • Paul48
    Paul48 Member Posts: 4,470
    edited February 2012

    have been in poorly ventilated attics, that water was dripping from every rafter. It looked like it was raining in there.Just a guess, but they may have been going after what they thought was chronic roof leaks.Wow.....Just took a look at the pictures, and that sheathing looks like Masonite.
  • icesailor
    icesailor Member Posts: 7,265
    Venting Attics: YouTube:

    Check out this YouTube Video. And check out the ones around it. The one linked talks about the soffit and ridge vents.
  • icesailor
    icesailor Member Posts: 7,265
    Chronic Roof Leaks:

    And if they were, they didn't understand what they were trying to fix.

    My biggest fear in  business is that someone wwill come to me with a complicated problem, I davise them, and it doesn't work. A loose, loose situation.

    If I'm correct and I solve the problem, it is a win,win situation.
  • mnestroy
    mnestroy Member Posts: 9
    Attic Venting

    I wanted to clairify, there are two roofs/two attics.

    One attic that is half over the 1st story living room and half over a 1 car garage.  This attic is the lower of the the two and has the furance pipe vent snaked though attic and out the roof (near the gable wall of the 2nd story attic)

    The attic above the garage looks pretty healthy, no signs of damage/mold and this roof has only 2 layers of shingles.

    The 2nd story attic that is a where all the mold and that side wet wall is located is the one with 3 layers of shingles.

    I to belive venting could be a problem.  However just a month ago when the problem frist started this was our first assumption and every softit was removed and where there was a section of the sofit that had holes a hole saw was used.  I have very narrow sofits.  After the channels there is only about 3-4inches of wood between.  In the front of the house the sofits where about 1 inch deep as the back (so much for consistancy, but whats an Inch, ehehe)

    I felt that the front sofits were still laking flow and I went back and used a sawzall and cut almost a complete channel the entire length of the sofit 3 inches wide. 

    I know there are some pretty crazy forumulas one can use to determine the exact ratio of air, 1/500 or 1/300 or 60% 40%... If people think getting down to this persise level of detail will reveal anything i can attempt to crunch some numbers, however to me there seems to be a huge room for huge margin of error when crunching those numbers.  I mean how do you  figure out the flow value of a 4x6 vinal sofit with a 2x4 channel running behind it?

    I have debated going continous sofit, they sell/stock these at home depot, it wouldnt be a very costly investment, a little tedius having to cut about 100 pieces. (right now I have the standard ones where its (6 inches of holes/ 6 inches of solid/6 inches of solid, then repeats)

    It has been suggested an attic fan, this is something I have no problems considering,  I am a bit nervous aobut putting a 'motor' in a place of my house that runs on its own that I can not monitor for failure (fire etc).  Is a solar powered unit safer in this regards?

    But back to the venting, lets assume I have poor venting.... I have already made attempts to improve the air movent without drastic changes (power fans, ridge vents, continous sofits etc)  In the past month I have almost doubled the amount of airflow  allowed in from the soffits, (maybe that is still not enoug), I previously only had sleds installed on every other joist, now i have them on every section.   I can clearly see plenty of daylight from inside the atic while looking down the sleds.  I have 4 8inch mushroom vents.  I know after all this you'll be expecting the exact messurements of my attic... which I did have however i can't locate it now so i will have to respond later with those numbers.

    So where do I go from here?  Do I start crunching some hard numbers, or will I find out that even if I am have those proper ratios 1/500 etc that in some cases that is still not enough venting??

    Do I just install an attic fan and see what happends?  It was suggested as an "experiement only" to secure a light plastic box fan to one of the vents and observe what happends.

    The problem I face now is winter is coming to and end... (well it never started this year) but the temps are going to be in the high 40's all week and Its safe to assume they will continue to go up from here.  This alone if I change nothing may "fix" the problem until next winter....

  • icesailor
    icesailor Member Posts: 7,265

    Where I live, the roofers use a starter strip that is ventilated under the drip edge. It is always used with those pan ventilators that have a name I can't remember. One picture you posted shows those foam pans under the plywood. If you see light in them as you said you do, and you either power fan it or ridge vent it, I'll bet it takes away a lot of your problems.

    If you have Cable and get HGTV, you really should watch Holmes on Homes and his new show, "Holmes Inspections". I love watching it for all the fluster clucks he runs into and fixes. It comes on on Sunday night. I'm watching it right now and he is going to get into a problem like yours.
  • icesailor
    icesailor Member Posts: 7,265
    edited February 2012
    Infra-Red Thermometer Guns:

    You need to go out and buy an Infra-Red Thermometer Gun. They are cheap. Radio Shack has them. Shoot all around the attic. Especially along where the mildew is. You will be really surprised at the temperatures you will find. It will give you a picture of what is going on.

    My wife had a knee replacement and it hasn't gone well. I bought her one so she could keep track of heat in her knee and leg. Once you have one, you will find ways to use it. I've used my work one that I have had for probably 10 years. I recently used it to locate radiant hot water heating pipes plastered in a ceiling. Use the thing on warm days and cold days. Keep a record of what you find. If you go on-line to and get the weather, put in your town or zip code and it will give you the dew point. That will give you an idea of when you can get condensation.

    The more you know, the more you will be able to get someone to help you. Understanding your problem and how it is happening is the key to solving it. I know what I know about this because I have had to deal with it numerous times. I've seen mold "Experts" be completely wrong in what they decided.

    Someone once gave me a definition of an "Expert".

    "X" is an unknown quantity. "Spurt" is a drip under pressure.

  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    definition of an "Expert"

    I like it. Even though I have been an expert in my area of professional expertise: not heating.

    I heard it as an expert, one considers the two parts of the word.

    An ex is a has-been, and a spurt is a drip under pressure. Who would want to be that?
  • 04090
    04090 Member Posts: 142
    The root

    of your problem is not likely anything to do with gas heating.  You post pictures of rotting sheathing and likely now punky framing members.  The flakeboard material on the roof appears to be, my best guess, 1/2" and both sagging between the rafters and deteriorating.  My guess is that someone rolled paint on the underside of the flakeboard as a means of adhering the junk back together. I question if it will even properly accept a pneumatic roofing nail if it's deteriorated.  Most improtantly, I suggest anyone climbing on that roof do so with care.  The sags show the material is breaking down and you don't want someone visiting the attic through the roof.

    I'd recommend just getting in a well qualified GC; one who can remove and replace siding after repairing the underlying structure, properly vent an attic and flash a roof. Even maybe replace the flakeboard.

    If you're an avid DIY'er, there's a lot of books in the library that show how things should be done.  If your house is part of a development, maybe your neighbots have been down the same road .

    Good luck!
  • icesailor
    icesailor Member Posts: 7,265

    Either way, we have managed to turn the word "Expert" into a perjorativr term.
  • Paul48
    Paul48 Member Posts: 4,470

    the length and width of that space?
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    we have managed to turn the word "Expert" into a pejorative term.

    I disagree. We did not do that, though we have both noticed it.

    The real trouble is that some bosses hire "experts" to take the blame for an unpopular decision they need (or think they need) to make. A dishonest way to evade the responsibility that is theirs alone. These "experts" know full well who will arrange for their consulting fee to be paid, and give the paymaster the results he wants. Such an "expert" may be no expert at all. But there was a big marked for them back in my day. Usually the boss had perfectly good employees who could give him the same or better answers, but he was too dim, or too gutless, to avail himself of the experience and expertise of the employees he already had; people more in touch with the problem.

    But maybe I am bitter about such things. Actually, no maybe about it.
  • mnestroy
    mnestroy Member Posts: 9
    Sorry For the Delay

    I apologize for the delay in responding.

    The 2nd story roof with all the issues is 25wide by 30feet deep.

    I had another roofing company come out, he did a complete investigation with thermal imaging to rule out poor insulation etc (or whatever he was looking for, eheh).

    He concluded a few things that he wanted to do.

    1. He obviously saw that the roof had a lot of things that were not done properly ie 3 layers of shingles etc. So his first solution was 'a new roof and new siding". Well I told him that unless he or I can get insurance to help offset the cost there is no way I can come up with 20k+ to invest in this house. With the housing market I have already lost so much money I told him that on paper it would make more sense to foreclose on the house before dropping 20k more in.

    So I told him lets focus on another solution/fix...

    2. Addressing humidity, he still thinks that venting is not enough. And suggested I go with a continuous soffit vent. Well this was frustrating because i had just spent 350 dollars to hire a handyman to pull down the current sofits and cut more holes behind the currrent sofits (they are the standard home depot models where its 6inches of holes/ 6 inches of solid / 6 inche sof solid (repeate))

    So over the weekend I went to home depot where they sell continuous sofit's so I have already have them all cut and plan on installing hem today or tomorrow, this will give me a significant increase in airflow compared to what I had 1month ago.

    The biggest problem I have is my sofits are very narrow... the front of the house after the channels there is only approximately 3 inches of visible sofits and the back is a little larger and there are 4 inches of visible sofits.

    So he was gong to give me a quote for this work but I can easily remove the old sofits, cut a channel with a sawzall, clean the sofits out, (and what i was going to use is thumb tacks to pin the sleds down so that they are curved down and there is no chance of insulation falling into that void as the sled will be more secured)

    3. He wanted to install an attic van.... he wanted to do it the "right way" which he says is to removed the other mushroom vents install plywood and put new shingles over them... my response was "this roof has three layers of shingles and there is nothing done right on this roof now so why spend 500 dollars starting now? instead of spending 500 dollars how about spending 50 dollars and sealing the ventsa with plywood/screws/caulk from the insdie and leaving the vents" and he said well yah you can do this, ehhehe so that is more logical to me

    4. The side wall.... while he doesn't think the pipe is the root cause he said its likely not helping... he suspects the flashing is part of the problem. Because the house was built 30 yrs ago i was told that housewraps were not common or not around, so its the wall then the siding, was explained that his solution would be to remove the siding which because its 30yr old aluminium he wouldn't be able to re-use it so he'd have to buy a new siding and paint it to match. Once siding is off he would replace the wall with plwood/insulation/house wrap and new flashing. he said that any water would find its way on top of the flashing and not behind the flashing like is taking place now. he also said this would require new shingles. The shingles on the garage near the vent that hold the flashing down are brittle and would require to be replaced but he said he should be able to find some that are close enough looking that it wouldn't be noticeable.

    Sorry for the long email....

    So I have yet to receive his estimates for everything, but from speaking to a lot of people they are pretty confident that insurance will not cover anything.

    1. So I am going to address the soffit venting by opening up the soffit plywood with a continous channel and using vynal continous sofits that HD sells.

    2. Once the weather improves I may instlal an attic fan

    3. the Side wall i am not sure what i will do yet...

    Can I get some feedback, based off the sizes i provided do you think the continous soffit will offer enough intake venting? I can't imagine an easy way of getting more natural air into attic without using other types of venting like those vents that go under the first few rows of shingles....

    Do you think I should instlal an attic fan? My main concern was that an attic fan would pull air form inside the house and not from the outside, I believe that once I install all these continous sofit vents I will have plenty of open air and a properly sized fan should not pull air from he house but from the sofit vents as designed. If you feel an attic fan is needed / would be helpful since i have 4 8inch mushroom vents, would you suggest placing fan in center and completely closing up the other fans so that air is being pulled from sofits and not shorting and pulling from a nearby mushroom vent?

    Lastly what do you think the odds are that if i increase attic venting that I can ignore/postpone repairs of the gable wall/flashing? My hope is that enough venting will allow that problem to continue but with enough venting the problem will not be a problem as any water will dry out before it becomes a problem :)

    One last thing!!! the mold... does anyone have an advice... i know somebody said since its in the attic and stack effect should force the air up and out the mold should not be an concern... but i still am on the fence about it... I personally think while mold is a health concern it seems the media may have made it out to worst than it really is... kinda like not wearing sunscreen :) But as a piece of mind is there a way to clean/trap it myself? I saw the previous mold remediation company had painted the decking with what looked like killz... so is this an effective treatment again? there is no mold on an of the frames, only on the plywood... would it be worth my trouble/effective to treat with any chemicals and then spray on or roll on origional killz???

  • PeterNH
    PeterNH Member Posts: 88


    Put the shop vac outside, use a scraper and physically remove/vacume as much mold as possible



    Go down to the local garden center buy a cheap little sprayer and a bottle of Captan. Mix it up to the highest concentration on the lable and spray the mold and all exposed boards and insulation.

    Wear a safety mask/respirator and mke sure there is maximum ventilation.

    Do it again in a couple more weeks.

    Then again.


    Now look into a protective coating. There is better stuff than kilz.

    Look into the:


  • Paul48
    Paul48 Member Posts: 4,470

    missed it the first have one photo showing the pipes looking down to the soffit. which also shows the same moisture damage.That would pretty much exclude the vent as the cause, and lead you to lack of soffit vent, too much vent above, by comparison, and insulation lacking on the perimeter.Your round vents are fine for the roof, provided they are near the peak of the roof and spaced evenly across the length.Add more soffit vent, get the air moving up there with some fans to help dry it out.Once dry, add more insulation,lots of it. Don't skimp on the perimeter and don't block the soffit vents.
  • icesailor
    icesailor Member Posts: 7,265

    I'll be brief (hopefully).

    Do the soffitt vents. Then, do a ridge vent. You take off the ridge cap and sawzall a slot so that there is an opening at the ridge Then install the screen cap and cover it with a shingle cap. If you do a ridge vent, you can't use those attic fan vents because they might short cycle, The ridge vents work really well.

    By what the guy did and said, he's in the bush league. You should have seen Holmes on Homes last night. He did two shows on big mold fiasco's like yours.

    I wouldn't be ripping off my roofs or re-siding. That's not your problem. Air movement is your solution.

  • Bob Harper
    Bob Harper Member Posts: 882

    Call your insurance carrier. You'd be surprised at what they will cover. You could contact a PA and have them go to bat for you.

    I suggest you read up at  Dr. Joe Lstiburek has a lot of free download articles on the subject and you'll be shocked at this views on attic ventilation.

    You could hire a contractor who is BPI certified who can conduct a blower door test with  infrared thermography, which will show you the extent of the moisture intrusion and any air bypasses. For sampling, you'd need an industrial hygienist and they ain't cheap, which is why I suggested the insurance route.

    You have multiple issues here and probably multiple sources of moisture. For instance, that fart fan with the plastic slinky vent may have become torn or disconnected and could discharge/ leak moisture into the attic or its discharge may not be making it outside. The exhaust fan probably is not sealed to the bathroom ceiling allowing moisture migration around it. Those boxes leak like a sieve on a good day anyway. A lot of that moisture appears to be coming up from the roof deck/ flashing. You can have your pvc vent tested by a plumber with inflatable test balls to see if the joints are intact but I doubt it is discharging sufficient moisture to get entrained back into the attic.

  • Tauno
    Tauno Member Posts: 3

     Looking at the photos, the one of the attic space with the venting does not seem to be the same venting as the one on the roof. Where is the wall in the attic if the outside wall is 15 inches from the vent? The corrugated plastic venting is not insulated, if this a bathroom vent,  that is a source of moisture as is the uninsulated furnace vent that is exposed in the attic space. The furnace vent looks to be a concentric vent on the roof but it does not appear to have any connection to supply intake air to the furnace in the attic space.

      Venting the attic would be treating a symptom to the problem, finding out were the moisture is coming from and eliminating that would be my first choice 
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