Hello,

I had my roof replaced last year but this winter (actually just February) has been hell in New England. The underside of the roof decking is soaking wet and I do not know why this would happen with a new roof. Is the extreme weather to blame or was the roof not installed correctly? Also what should I do to rectify this issue? Also, there is mold growing on the wet portion. Should I get in there with a bleach/water solution or is this a waste of time in the attic since I do not live up there?

 

Welcome to the forums.

What's it look like on the outside?

 

Actually forgot to mention that part. There is a slight sag in the roof, probably because of the weight of the snow we got. I raked it the next morning after every storm, but still must have affected it. Other than that, yesterday the last of the remnant snow melted and it should start drying out. I was going to wait for that to tackle the mold.

 

The moisture is most likely coming from the warm humid air inside your home leaking into the attic and not being ventilated out. I assume that fan we see is not being currently used and should probably not be, even in the summer until the above air leakage is resolved.

Thar looks like blown in cellulose so leaks may be buried but either leaks or lack of a vapor barrier will still let the moisture through.

Other possibilities, but we will need more information.

What do you currently have for attic ventilation. I don't see baffles down in those soffits so if there are soffit vents the could be filled.

You said a new roof, did they install a ridge vent? Are there gable vents?

Are you nears a significant moisture source, humid air?

Do you run a humidifier in the house?

Bud

 

I am hesitant to think that the moisture is related to air in the home leaking into the attain since this is the northern portion of the roof that gets minimal sun so didn't melt like the rest. also, this area has almost nowhere that air can leak in.


I know I am in the wrong but I do not have soffits. When they installed the ridge vent, they realized that the house did not have soffits even though it appeared so at first. So I have gable/ridge. I am going to have a company install the smartvent system instead of the soffits so that ventilation would be adequate.

As for moisture in the house, there is minimal moisture. I will run a humnidifier in the house briefly to get the moisture level into the mid-40's and this particular area is nowhere close to any area of air leakage in the house. But I don't think there is anywhere allowing air to leak in. I tried my hardest to seal up all possible air entry points when I had the attic insulated.

Is it possible the roof job was done wrong and for that reason, the water soaked under the shingles from ice and snow and freezing/refreezing/melting? Should a roof protect against this?
Bud

Read more: http://www.doityourself.com/forum/wa...#ixzz3TzmkagLE

 

70 degree air at 42% relative humidity has a dew point of 46°, which I'm sure the temperature of your roof deck under a load of snow is well below.

This is just my opinion, but the moisture that caused the mold came from the air in the attic. Now, whether it first leaked in, evaporated, and then condensed on the bottom of the roof is a guess, but doubtful. Most likely, it is diffusing right through your ceiling or following the many small leaks. Example, did you seal the tops of all walls? Where sheetrock ends and is not glued to the framing, air seeps right through. Now, how much? A typical home has to exchange ALL of its inside air every 3 hours. If it takes longer we hear complaints about condensation and ice on windows. But even if yours takes 4 hours, that is gallons of water per day and the majority of that escaping air usually finds it's way into the attic.

If you turned your house upside down and filled it with water, the water would pour out the attic.

This happens in a lot of homes, but any amount of ventilation placed high and low will allow a constant flow of fresh air, which being cold will also be low in humidity and both dry and exhaust that moisture.
http://www.efficiencyvermont.com/ste...ide_062507.pdf

Bud

 

Bud,

thanks for the information. I am definitely going to get the ventilation fixed so it appropriately vents the attic space. I think even if it was or wasn't the actual cause, ventilation would help been a key aspect in minimizing the moisture.

 

I think you are right, if you had good ventilation, what you have now would not have happened.

When you start the real challenge, cleaning that up, get the best face mask you can and exhaust that air as you work to keep the mold spores out of the house. One of our posters a few years ago talked about Katrina and how mold sinks roots into the wood. They had to pressure wash all surfaces, dry it, and then seal with special paints to encapsulate those roots.

But I'm far from a mold expert. Others here may be able to advise when you get to that.

Bud

 

The north side is almost always where you see the worst frost, since that part of the roof is the coldest (doesn't get sun and is covered in snow/ice, whereas the south side usually melts first). This has nothing to do with your new roof and everything to do with a hard winter.

 

Ok understood. So when it comes to drying all this out and removing the mold, any suggestions?

 

I agree with Bud's conclusion, this is from warm moist air entering the attic and condensing on the underside of the roof deck. Given the fact that it is worse on the north side is even stronger evidence. Proper venting will make all the difference in the world.

 

To have that much mold growing this has to have been going on for a long time, not just this winter.
Are you 100% they did not just install that vented soffit over the old plywood and never made any holes for real venting?
I've seen it done wrong like that many many times.
As bad as that old decking is I would have removed all of it and sheathed over the whole roof before installing new shingles.
Bet the roofer just showed and gave a price on a new roof and never went into the attic.
Bleach is not going to do a thing.
Need a product like Boracare with mildicide.
Any exterminator could do it, but it's not going to do a thing to strengthen the wood so it will hold the roofing nails.
House looks old enough to be balloon framed, is so those walls are open all the way from the crawl space or basement to the attic so your sucking moist air in from that area.
Walls should have been fire blocked before insulating.
In your area there should have been 12" of insulation R-50.

 

Might sound dumb, but I wanted to let you know that the ground area is 12 inches of cellulose insulation, not mold. Not sure if you thought it was mold or not.

I know the mold wasn't there at the beginning of the winter. Is it possible that the moisture brought an old mold issue back to life? The mold only seems prevalent in this portion of the attic for some reason.

I have no soffit vents at all. I have an overhang but it is not a true soffit because it is sealed on the side of the house.

You are right, the roofer did not really inspect the attic, he took a peak in it more than anything.

I am going to have to work on getting the proper ventilation ASAP and work on stopping that mold. Will look at the Borax to start working at the mold. Everything is starting to dry out so I have a feeling it will start to get a bit better.

 

Can you list exactly what they applied/did to the roof, including details like tear-off, sheathing overlay, membranes used, shingles used. Thanks.

While I'm certainly of the crowd that believes you have an interior flow of moist air at the root of the problem, there are other factors that may not exactly be helping the situation.

Although you have measured the RH and it doesn't seem inordinately high, there can be great discrepancies in accuracy of instruments. Is the basement damp, are there any vapor retarders included in the construction that you know of? What about bath and kitchen fans?

 

Calvert,

To answer the question about the damp air movement, I am almost positive there is minimal direct connection from the crawl space to the attic. I live in a 1 floor house, and in the basement, I have a dehumidifier. I checked the bathroom fan and it is surely venting properly. I just cannot seem to find any areas of significant air movement.

As for the roof, they replaced in March of last year. This is what the work order said the did:

-Apply 6ft Ice/water shield to eaves, apply ice and water shield in all valleys, under all flashing and around chimneys.
-Apply 8 inches of drip edge to perimeter of roof.
-Install Certainteed singles and cap
-Reflash Chimneys
-Weave all valleys
-Oh! and "Attic to be ventilated properly!"

They said Gable vents and ridge would be fine since it is a crawl space attic. but obviously not.

 

The roofing sounds like it was done right ( assuming there was no rotten sheathing or they fixed it), but the venting, no. The problem with only having gable and ridge vents is you are only really venting the top of the roof. Air goes on the gable vent and out the ridge, leaving the moisture below still in the attic. if you do add soffit vents, i would recommend removing the gable vents.

 

I'll be short.
The need for high and low venting is because the natural pressure is directly related to the difference in height between high and low. In a low attic, the available height is already limited, so opening up those soffits is important.

Someone previously asked the age of the house and is the wall framing is balloon construction. It is easier to see on the gable ends, but look to see if the wall cavity goes straight down. Probably not but need to confirm.

Without getting into a debate with Keith, when the time comes to keep or remove those gable vents, I'll explain how to decide. Don't want to drift here.

Their list of work done sounds good, but do check to see if they opened up a gap on each side of the ridge beam. I can see the beam in one of the pictures but can't tell.

When it comes to cleaning up that roof, I would cover the existing insulation and bring up something to walk on. It will be slow, but you need to be sure you don't contaminate everything else anymore than possible. Maybe Airman will comment on a best approach.

Bud

 

I have a company looking how to add a soffit vent equivalent since I do not have soffits and I am not willing to try to vent that myself.

the house was built in 1910 with from what I can tell several additions. I have no idea when what was built etc.

As for your question about the cavity straight down, I checked last night and there is no cavity straight down. there is wood blocking everything.

Everything is starting to dry out wit the warming up and the snow melting off the roof which is good news.

I will keep everyone posted on the ventilation situation when that time comes. I look forward to the input on sealing the gables. I can definitely tackle that myself.