This is kinda like asking about blood in your stool. You really need to ask someone that can give everything a good look.

From what you say I hope you have deep pockets.

@johnpowell , I don’t have deep pockets at all. I sure hope that it is something that I can fix.

How old is your roof @wilma? The year prior to replacing ours, we had way too much moisture in our home.

Do you have a dehumidifier running in your basement at all times?

I’m thinking this may be more than one issue. Yes, moisture in the attic is a serious problem. Yes, it can lead to mold, not only in the attic, but will spread quickly to other areas of your home if not taken care of quickly.

For right now, I’d also put a dehumidifier in the attic to help you dry it out pronto. Then, I’d call several roofers and get estimates.

Wilma, this is one of the main problems with owning an old house.

The open duct work from the basement to the attic is one major problem.

I assume you have electricity. If so, tomorrow, call your electricity provider and ask the for an inspection and suggestion. Most have free inspections. We did this years ago and it has saved us a ton of money. You have got to keep the moisture in the ground and not in your house. You know this.

Also, remember this, mold can make you very sick with lung infections.

Make the call tomorrow to your electricity provider. My provider had a payment plan that fit right into my budget.

Better to be safe, than sorry.

@SpatzieLover the roof is about 13 years old. We don’t have a dehumidifier, the living space is very dry in the winter. I’m thinking we might need more ventilation in the attic as well.
Could the moister in the picture be condensing there on the back of the picture because the upstairs room is cold and the chimney wall is warmer? Is the moisture coming from the room or through the wall from the chimney space?

@john65pennington So my power company will inspect and analyze my home for free? I didn’t know that.
I know that the mold can be bad, I just can’t get my husband to believe me about that.

There is damp in my house too with wet patches on the walls occasionally on the chimney breast. As it is rented accommodation I have just borrowed a dehumidifier from my landlord. not a long term solution but will help to postpone the mould growth until you can afford to do something more long-term.

You need to call a general contractor right away to prevent it from getting worse. But get a general contractor, not some “Water and Fire Emergency Specialist.” Many of them might be legit, but too many of them are scammers. They’ll just put a dehumidifier in your house and call it a day, and then after a month bill you $500 a day to rent the dehumidifier.

My own first suspicion would be the roof flashing around the chimney. Flashing, if you don’t already know, is the lead sheeting that is formed around the base of the chimney (or any other roof protrusion) to form a water barrier around the protrusion and then be covered on the flats by the shingles. Flashing can wear or be damaged, and the seams can require new caulking (or tarring). If the wall “next to the chimney” is actually “wet” then that’s going to be the first thing I examine, and very closely, too.

A humid or damp attic is its own problem, but unless you actually have a roof problem (or defect in the wall or siding that allows ingress of rain and snow), then you shouldn’t actually have noticeable “wet” inside the house. (You could also have a piping leak, but you ought not to have much piping in close proximity to the chimney, I think.)

The unfinished duct to the attic is worth a look, because you could very well be pushing relatively more humid air from the basement into the attic, but attics should be ventilated with open vents on the gables to foster good air circulation. In fact, in modern attics those vents are so open as to allow daylight.

@wilma Once the moisture comes in, if you don’t have proper attic venting, the moisture will travel. In our attic, we have an attic fan (with an auto-thermostat), our main bathroom vents out (which you also maty need to check since you have an older home), two turbine vents (these never stop spinning and always pull extra moisture out) and we have roof vents at our gutter line.

My other thought is similar to @CWOTUS. It could be a flashing issue. I’m still thinking that what you’re describing sounds like a compund issue.

If you have a brick chimney, do you have a proper chimney cap? Has your chimney been tuck pointed recently? When was the last time you had a full chimney inspection?

Even with a good chimney cap & tuck pointing, in this weather, our chimney draws in a lot of moisture. We run our HVAC fan on low to keep the air/moisture circulating.

I believe you live in the same general region that I reside in. If I’m correct, I cannot imagine not having a dehumidifier running in the basement. Yes, the living area in our home tends to be dry this time of year. However, our basement without a dehumidifier would be moldy/musty.

Prior to our roof repairs, we had to solve our moisture build up with oodles of Damp-rid products along with a dehumidifier added to the attic. We also ran a fan on low to keep the air circulating.

@SpatzieLover I think you are right that it is a compound problem. We have a very small what we call a Michigan Basement. It was a dirt floor, now cement, but only the furnace is down there and access to the crawlspace under the rest of the house. I suppose we could run a dehumidifier there. I think we need more ventilation in the attic, but I can’t convince my husband of this. There is no chimney cap it’s just open.
@CWOTUS the chimney flashing is gone and roof tar has been gunked up around there. That is probably leaking at least a little bit. I think that moisture is coming up that open duct and I’m going to try and solve that myself.

I guess I need to find a chimney guy (or gal) and see about getting this problem solved before it gets any bigger.

@wilma At least get a bucket size of the DampRid down there for now. See how fast it fills. That will give you an indication as to how big of an issue this is.

Since you know you don’t have a chimney cap, stick a DampRid in the fireplace for now. It’ll prevent that moisture from drawing in further.

You’ll have to have your husband reas up on this or something. Your attic needs to breathe.

You can put cat litter and saw dust in your attic. This will help a tiny bit. You can also get dehumidifiers. Good luck.

Balloon construction (where wall studs have no fire breaks) are notorious for not only moisture but corridors for critters and smells from top to bottom. The Chimney is a separate issue. Barring Flashing problems, they very often used a different grade of sand in mortar 100 years ago than they do today. It lets moisture travel down through very easily. Clearly at least the chimney should be capped, fans or other positive ventilation installed in the attic and basement, and the exposed brick tuck-pointed with modern moisture resistant mortar. We had a similar problem in our first home. ended up re-building the chimney. Good luck to you.

@wilma What kind of floor in the basement? It sounds like the duct is bringing moisture from there and once in the attic it has no place to go. Most newer construction has small ducts venting to the attic and the attic is well ventilated.

The original floor was dirt, it is now cement but opens to a large dirt crawl space. The basement area is not at all living space, more like a root cellar with the furnace in it. My husband put the duct in, intending to run heat from the furnace up to the attic and back down into the rooms on the second floor. My husband never finished the project so the duct is still open from basement/crawlspace to the attic. It runs alongside the chimney.

@wilma I bet that duct is bringing air out of the basement like crazy. Warming it with the chimney makes the affect worse. A cold woodstove doesn’t always vent well when you first start it. It needs to warm the chimney a little. I bet you have a super efficient duct there. He needs to seal it.

Another concern with that open duct @wilma… Have you had your basement tested for Radon? In our region, I’d be very concerned with drawing basement air up to the living floor levels for this reason alone.

@SpatzieLover GA

@SpatzieLover no we haven’t been tested for radon, good call there.
@Adirondackwannabe, I agree, you want to come on up here and help me convince him of that? ;)
I’m going to block the duct myself, I can do that in the basement and the attic. I guess I need to call a chimney repair person too, I’m not getting on the roof, it’s very steep.

Can you get in your attic easily @wilma? If so, just go up & touch the roof. If you notice condensation, you have an issue. Do you see mold or water damage at the chimney area?

@wilma If you can seal the basement end that should help.

@wilma I just got an idea how to prove it to him. Hold a piece of cardboard a little away from the end of the duct. Let it go. If it’s moving as much air as I suspect it will suck that right up against the bottom of the duct.

Yep @Adirondackwannabe I think you’re on to how @wilma will have to drive this point across to her husband.

@SpatzieLover I’m surprised he doesn’t get it. It’s a classic chimney affect.

@Adirondackwannabe He may be presenting with male ego affect “Something I did is causing damage? I don’t think so.”

@SpatzieLover I think you nailed it. Any other way we could could convince him?

-Have him stick his hand in the top of that duct (I bet there’s condensation there).

-Show him an amount of water collected in a 24hr period.

Really, cardboard should be sufficient….but it won’t prove how much damage the draft is doing. I think he’ll need a box of proof.

He may <sigh> need to hear this from another man. Ideally a chimney or roof expert that comes out for an estimate.

It’s worse than I thought, there is mold on the rafters and underside of the roof.
I went up in the attic before I sealed the duct in the basement. I uncovered the duct up there, there had been a piece of foam rubber laying over it. As I looked down into it my hair was blowing back like a model posing in front of a fan!
There had been just a little bit of mold around the chimney before, now it’s quite extensive, both black and green.
My husband just called to ask what was for supper tonight. I told him supper would be waiting a while, he better bring in his big flashlight from his truck because we would be going up in the attic as soon as he got home. I told him about the moisture and the mold and he got all huffy and pissy. (yes @SpatzieLover you are very correct about the __“Something I did is causing damage? I don’t think so.”__)
He is also very much a “out of sight, out of mind, I don’t see a problem” kind of guy.
Now if he had discovered the problem, and it had been caused by something I had done, it would be a whole ‘nother story!

I wonder if the repairs can be made in winter? We are having a mild winter, but this looks like it could be a big job.

@wilma Yikes. Good thing you acted on it before it got worse.

Yes, it can be done in winter @wilma. Our roofers were done in one full day.

@wilma How did you make out?

He took a look in the attic, got mad and told me to get someone to take a look at it and give an estimate on a fix.
I didn’t say “I told you so” even though I had.

The mold seems to have exploded in such a short time. When I was up there in December there was just a little bit, and we have lived in this house for almost 30 years, so why now is the mold forming, and increasing so quickly? The only change lately is that we got a different furnace this winter, a newer more efficient one.

There are way to many variables to guess at one. Could be anything from the new furnace to the weather.

@wilma – You might also want to consider installing a UV filter in your new HVAC system.

Well the guy came yesterday to look at the problem. As soon as I told him we had gotten a new furnace this winter he figured it out even before he went into the attic.
This is basically what he told me.
There are several reasons why new furnaces and existing masonry chimneys aren’t compatible. The size of the chimney can be an issue. Modern, higher-efficiency furnaces transfer more heat into your home and less heat up the chimney than older, less-efficient units. While this means the consumer is getting more for their energy dollar, it also means that the existing chimney might now be too large for the new furnace. The result could be improper ventilation of flue products, which can cause condensation problems inside the chimney. Condensation in your chimney is the cause of two major problems. The water combines with flue gases and forms corrosive acids that eat away at the chimney, deteriorating tiles, bricks and mortar. Secondly, in winter, moisture freezes and thaws, breaking away mortar and bricks. Resulting damage can be extensive. A chimney can be destroyed and deterioration can create leaks into the home. Moisture can damage interior dry wall near the chimney and run back into the furnace, causing corrosion there, too. Source

So the new furnace combined with the open duct, a bit of a leak around the chimney and very poor ventilation in my attic is the problem. The old lack of ventilation wasn’t a problem until the new furnace was put in. The old furnace sent a very hot exhaust up the chimney and didn’t have all the moisture. When they guy and I went in the attic and looked at the chimney water was literally dripping out of every mortar joint. I had thought that that was from the leaky flashing, but he said no, it’s coming up from the furnace and your whole chimney is saturated with moisture.
He said the water drops in the picture came directly through the wall behind the picture (the chimney wall) as water vapor and condensed on the glass.

We are getting a chimney liner put in, and when the weather improves the flashing repaired. I have already closed up the open duct and we will be getting more, proper ventilation put in.
Now I need to get the attic dried out, I’ll be de-humidifier shopping today.

Thanks for all your help!

@wilma Yay. Homerun lady. Maybe you should go into contracting your services out to other homeowners.

Thanks, @wilma. I learned something new today. It’s already a better day than it was before I read your follow-up.

4 issues in one small space? Thank goodness the contractor was a good one, willing to explain the details.

At least a liner is a much cheaper solution than a brand new chimney ;)

Actually, while cleaning up my kitchen @wilma I came to one more thought:

Possibly you should have your HVAC installer come out and price out how much it would be to have your furnace vent out (not through the chimney at all). One, he should be aware of the issue he caused to your home. Two, this may be a quicker & cheaper fix for now (if the chimney liner is needed for no other reason).

Our hybrid HVAC installers vented ours out the same day they did the install (in WI it’s illegal for them to vent out the chimeny now). They also were kind enough to re-do the water heater venting at the same time, free of charge (it had been venting toward our patio in an annoying way).

That’s a good point, @SpatzieLover. In fact, most residential gas furnaces now only vent through a wall, since the exhaust gas now doesn’t contain enough heat to carry it up a chimney flue.

I also wanted to make one other brief correction about “moisture”. When you look at the gases exiting someone’s chimney from an oil furnace (most common in New England) what you see as white “smoke” probably isn’t smoke at all. A properly tuned furnace won’t exhaust much (if any) visible smoke. What you do see is a lot of water vapor.

All common fuel contains some moisture (water) content. Since it doesn’t burn in the combustion process, it does turn to steam and exit the furnace as water vapor. When it hits the cold air outside it condenses to steam and looks like smoke.

This is also true of most power plants, too. What you see from the hyperbolic cooling towers is ONLY steam, and what comes out of the chimney (visibly) is MOSTLY steam. And yes, there’s a lot of that. The moisture content of coal, for example, often ranges upwards of 10% by weight, and can be a lot higher than that.

The same holds true for cars. When you see someone’s exhaust on a cold day, most of what you see is water vapor.

@SpatzieLover I asked my husband to call the installer and discuss the problem. I wasn’t home when the installation was done but my husband did tell me last night that “Scott (installer) did say that we might want to get a vent stack up the chimney now”.
That could be interpreted a couple of ways. Scot may have said it that way, or he may have said “you will need a new vent stack up the chimney now”.
(rolls eyes) I’ll leave it at that and let him talk to the installer.

@SpatzieLover

“At least a liner is a much cheaper solution than a brand new chimney ;)”

How much do you think a new chimney would cost?

I had a 1-story chimney replaced in 1995 for about $7,000.

The reason for that was even though my original chimney was reinforced with rebars, it was torn in half by the 1994 Northridge earthquake.

@Brian1946 A liner costs about $50—$60 a linear foot. A new chimney for my home would be about $20K….the liner about $2k.

@wilma – Glad you found the problem. You’ll need a commercial dehumidifier, not one of those cheap little gizmos that hook into your HVAC to help people with dry skin. But, again, don’t get one from one of those “water damage emergency specialists” or they’ll rip you off royally.

The estimate for a poured liner is $3,500 for my 32 foot chimney. I haven’t got an estimate yet for a metal vent that might be put down my existing chimney and hooked onto the furnace. That should be quite a bit cheaper, but I’m not sure it would be as good.

Since it’s a high efficiency furnace that doesn’t put out hot gas, can you bypass the chimney altogether and vent it out the side of the basement like a dryer?

@HungryGuy I am checking into that. I don’t know if it would be possible with my situation. Also if it was possible, my problem with that would be that I have tried to maintain the integrity and original look and character my old house. The vent would most likely be in a very visible place. It would be nice to get rid of the chimney and it’s problems going through the roof, but then the house would look different and a hundred year old house always had at least one chimney. Although when I bought the house 30 years ago, I did have one chimney removed that was no longer functional. I struggle with doing the right thing about those kinds of decisions.

@wilma The vent looks absolutely no different than a dryer vent. It’s white pvc end of a pipe. They’d vent it where it’d be a bit hidden by landscaping, or out by your A/C unit.

@SpatzieLover I have no A/C unit. I will check to see if it is possible, and if so how it might be hidden.