Thread: Black soot on walls

I was called out to find what was causing black soot on first floor walls. The had a coal burning many years ago , which was converted to gas , than a 80% was installed about ten years ago. five years ago this black soot started appearing on the walls. A new roof was installed at the same time. No ridge vents but it does have gable vents that are open. Furnace was checked for gas leaks( none). Attic was clean( no soot). Chimney looks good. looks like a coal mine in the first floor. Second floor has some soot

Similar Threads:

• Stains on the interior walls?
• Holding up the crawlspace walls
• Black stuff on a wall.
• black flex gas line
• Black marks on ceiling

Cracked heat exchanger. Did you do a carbon Monoxide test at the registers?

Tim,
I think it sounds more like a condensation related mold build up.
Check all the usual suspects, lack of exhaust fans, probable humidifier, probable better sealed windows and doors and the like. See it a lot up here in WI.

Jim Weyenberg
HouseMaster Inc.

Originally Posted by wayne soper

Cracked heat exchanger. Did you do a carbon Monoxide test at the registers?

Was it worse around the heat registers?

Is it possible that coal dust is being picked up and distributed around the house from the basement?

Sounds like some improvements to the house have been made, which could well include sealing the drafty old house up tighter and the house does not like it.

Could be (probably are) leaking paths up through the floors and walls into the first floor and up, all the newer energy efficiency stuff sounds like they have slowly sealed the house up too much without adding fresh air intakes with heat exchangers to reclaim the energy.

I suspect the solution is not going to be just easy thing, that it was caused by several improvements and the pressures need to be checked - do you have a manometer to check pressure differentials with? Sounds like it is time for a specialized HVAC contractor to come in and "building science" evaluate the house as a complete system, not just the HVAC system.

It could also be a condition called Ghosting or thermal transfer. Or could also be flu gas spillage. Try turning on all exhaust vents and check draft at water heater and furnace vents.
Bill Lindberg
Advantage Plus Home Inspections.

Were the owners candle burners?

He is not saying Black Marks on the walls, He is saying there is SOOT on the walls. This person is a Home inspector and should know the difference. I am assuming he does.
Soot could be from past coal burning,but to properly protect your client you must think first of the things that could KILL. Like Carbon Monoxide.
So test for heat exchanger cracks and if all good go on to the next step. Protect your client!!

The black marks from candles is soot. I would check that possibility out first.

I was called by a new homeowner to a home that had soot on the carpeting around the registers, on the walls and in the TV cutout in the bedroom above a direct vent gas fireplace. Well, they blamed the gas fireplace, of course. Fireplace checked out OK and after scratching my head for an hour of so, I noticed 2 screws beside the TV area. I asked if the previous owner had wall mounted candles, they said yes. The previous owner loved their candles, but did not trim the wicks. That caused the soot to be sucked into the HVAC system and blown out through the rest of the house. There were no soot "streaks" on the walls where the candles were hanging.

Maybe this helps.

How long ago did they burn coal?

My guess it has nothing to do with coal, but candles, location of house (ie. busy thoroughfare, industrial area) poorly insulated and lots of air leakage.

The furnace was checked twice Once by a company that I sent in and by a company the client called. Mold was my first thought,so I sent a sample to my lab. It is carbon dust. Basement does have standing water. Coal was used up until early 50's. More soot around registers, both cold and hot. No ac No candles were burned. Furnace had a new flue liner installed in chimney, required here in Stark county. The client had a stack of used filters( maybe 10) that she had changed monthly, all were black. Duct work was black on the inside also. Any thoughts about having the duct work cleaned. Client is in early 70's
Thanks guys

Originally Posted by Timothy M. Barr

...Any thoughts about having the duct work cleaned...

Here's an interesting article on duct cleaning.

Continuing Discussions on Indoor Mould- Duct Cleaning

I've investigated over 50 formal cases of "Black Soot Deposition" or the newer term, "Black Particulate Matter" and I, nor any other engineer or industrial hygienist I've worked with can visually tell what the material is or where it came from. That's why we have testing laboratories.

I've posted many times on this site about BPM so please conduct a search but understand without proper sampling and proper lab tests, you are 100% guessing at the etiology of this material. Most often, it is a combination of things that comprise the material seen.

You also need an investigator who understands construction, building science, mechanical systems and in particular BPM to properly survey the entire house and rule out certain causative factors.

To declare the depositions to be just from candles or coal soot or any other source is junk science not to mention incomplete. You have many sources of particulates than may collect and appear black must like soot including hydrocarbon soot. However, you also need to understand the mechanism how it got distributed across the home and why it deposited where it did. Only then can you guide remediation. Otherwise, you'll be back cleaning up the same mess.

If they need someone to investigate this case, call me.
HTH,
Bob

Originally Posted by Timothy M. Barr

I sent a sample to my lab. It is carbon dust.

Originally Posted by Bob Harper

That's why we have testing laboratories.

I've posted many times on this site about BPM so please conduct a search but understand without proper sampling and proper lab tests, you are 100% guessing at the etiology of this material.

Bob,

He already said it was tested, came back as carbon dust.

That's my point Jerry. What does 'carbon dust' mean? How does that differentiate from one source or carbon with another? What was the lab test used? How many samples from where using what technique, what sample container, storage, etc.? Were there any other particulates included in the matrix or was it purely carbonaceous? If it is infact coal dust and not soot, that is totally different from coal soot. Why? How did it get all over the house? Is there a breach in the chimney? Was the chimney relined? Was the chimney swept prior to relining? Has anybody conducted combustion analysis and draft interference testing? Is the duct work sealed? Major issues that effect the safety of the home, the continued distribution of particulates and determining what remediation is in order.

Let me restate my position: calling this "carbon dust" is useless information at this point.
Bob

Originally Posted by Bob Harper

That's my point Jerry. What does 'carbon dust' mean?

Point taken.

If it is infact coal dust and not soot, that is totally different from coal soot. Why? How did it get all over the house? Is there a breach in the chimney? Was the chimney relined?

My thoughts are from coal dust from the previously stored coal.

Why and how were my questions, no breach of the chimney needed.

Carbon or coal dust I don't really care I was looking for ideas from where it might be coming from. The cliet doesn't burn candles The furance was checked by two different companys, so that rules out that. Coal was removed 40 plus years ago. Basement has been painted. I closed all the doors and windows,turned a fan on with the front door open .That did not effect pilot light on hot water tank or the furnace. This started when a new roof was installed. Is it possible the coal dust ( carbon dust) is being pulled thru the plasted wall or is setteling out from the walls?

Originally Posted by Timothy M. Barr

Carbon or coal dust I don't really care I was looking for ideas from where it might be coming from. The cliet doesn't burn candles The furance was checked by two different companys, so that rules out that. Coal was removed 40 plus years ago. Basement has been painted. I closed all the doors and windows,turned a fan on with the front door open .That did not effect pilot light on hot water tank or the furnace. This started when a new roof was installed. Is it possible the coal dust ( carbon dust) is being pulled thru the plasted wall or is setteling out from the walls?

Anything is possible with an old home. I inspect a good number of 100-200 year old homes (the ones that did not get burned to the ground during the War of Northern Aggression! ) and just about all of them have coal dust, soot, carbon, etc in them. Most of the time I find it in the attic and basements. Also most have had fires in their attics at sometime, most likely from the coal dust, sparks, etc.

I would bet that the new roof and HVAC has created a new draft or ventilation that has not been seen in the home before. The homes construction in most likely "balloon" style verses "platform" style. So, you will have open walls that communicate with the attic, the floors and the basement. Those spaces act like chimneys and can move all type of crud around a home.

Is the house located in an industrial area?

thank you Scott I just called the client The walls are empty no insulation, so the posiblity of years of dust are coming from in the walls. Rural area rail road tracks about 3/4 mile away

Originally Posted by Scott Patterson

Anything is possible with an old home. I inspect a good number of 100-200 year old homes (the ones that did not get burned to the ground during the War of Northern Aggression! ) and just about all of them have coal dust, soot, carbon, etc in them. Most of the time I find it in the attic and basements. Also most have had fires in their attics at sometime, most likely from the coal dust, sparks, etc.

I would bet that the new roof and HVAC has created a new draft or ventilation that has not been seen in the home before. The homes construction in most likely "balloon" style verses "platform" style. So, you will have open walls that communicate with the attic, the floors and the basement. Those spaces act like chimneys and can move all type of crud around a home.

Scott,

That's what I am thinking.

In addition to the new roof and HVAC, I'm sure other things have changed too, exhaust fan(s), insulation, you name it, it does not take much to change the ventilation in and through an older home.

This Might help. BSD-150: Black Stains on Carpets and Ghosting of Framing —

I seen this several times and candles where the culprit.

I have seen the ghosting or Brownian effect on walls on several occasions caused by LP gas logs installed in an existing fireplace. The heat of the flame was not hot enough to properly draft up the chimney (backdrafting)and was depositing a layer of soot on the walls each time the logs were used. In one case the damper had not been secured open to allow the logs to vent up the chimney. This backdrafting problem can also be from an appliance vented into a chimney that does not have the correct size flue for that appliance.
I have also seen puff-backs from oil-fired furnaces, but this deposits an oil/sooty film on everything. This usually is transmitted through ductwork or even transferred through walls to baseboard heater and/or cast iron radiators by static electricity along the boiler sytems' pipes.
The walls will need to be cleaned by professionals ("Serv-Pro" or "Service Master" restoration type companies) with "chemical sponges" and then primed with a stain blocking paint such as "Kilz" and then top coated with regular wall paint.
Good luck,
Jim

Many people are bringing up "ghosting" but nothing was said about "ghosting", which is when the framing shows through because of the BPM which collect on the cooler surface right at the framing.

This was described as:

Originally Posted by Timothy M. Barr

looks like a coal mine in the first floor.

To me, that is not "ghosting" at the framing.

Originally Posted by Jerry Peck

Many people are bringing up "ghosting" but nothing was said about "ghosting", which is when the framing shows through because of the BPM which collect on the cooler surface right at the framing.

This was described as:



To me, that is not "ghosting" at the framing.

I think that most who are talking about "ghosting" have not seen a older home with ventilation induced problems. Plaster walls do not ghost, or I should I say it would be very unlikely for them to ghost.

Old homes were not built for modern HVAC units and most are not modified properly when an modern HVAC system is installed. With uninsulated walls, and open balloon framing, you will have all types of problems and issues when you install a modern HVAC system in a old home.

I see older housing with lath and plaster ghosting occassionally fwiw and it does not appear to be the result of HVAC but rather low insulation levels or non existant.

I am not an expert on this by any means.

But from the information you have given, you have named the pollutant as coal dust, ruled out candles, identified the problem as worse around the hvac registers, ruled out furnace and venting problems.

It therefore seem you have eliminated every obvious scenario except for the depressurization of building cavities and drawing preexisting coal dust from the interstitial cavities.

The next logical step to me would be to recommend a blower door test to find and seal the openings from the interstitial building cavities and/or a pressure test with a manometer along with installation of a fresh air supply to put the building under slight positive pressure to drive out the pollutants.

Look in Building Science Digest 109 for good information on building pressure and environmental problems. I tried to get a link posted, but I could not get the URL to post here, but try this.
BSD-109: Pressures in Buildings — science digest 109

Originally Posted by Jim Luttrall

The next logical step to me would be to recommend a blower door test to find and seal the openings from the interstitial building cavities and/or a pressure test with a manometer along with installation of a fresh air supply to put the building under slight positive pressure to drive out the pollutants.

I suspect that if a blower door test is done ... there will be coal duct flying all around inside that home.



But now we are talking about what I was referring to.

Originally Posted by Jerry Peck

But now we are talking about what I was referring to.

Yep, but the discussion has taken various twists and turns on many other theories that have been explained away by the OP.
Rule out the obvious and deal with what is left.
Coal dust was not created by anything currently in the home, it is just getting moved around.

Originally Posted by Jim Luttrall

Coal dust was not created by anything currently in the home, it is just getting moved around.

My point exactly.

When I was a kid and lived up 40 mile south of Buffalo, my aunt and uncle's house next door used coal at that time and I remember their basement was always covered in coal dust from the delivery of the coal and the use of the coal - their basement was not useful for much because of that coal dust.

I don't recall what we used for heat in our house up there, but the basement was clean and we used it for many things.

With all that coal dust in the basement and in the air, the inside the wall cavities are probably loaded with that coal dust. Which gets down to what Scott, you and I are talking about.

The movement of air within a residential dwelling and/or a commercial office building of any age is a science unto itself. I agree with Bob Harper and have sat through a number of seminars over the years with HVAC gurus and other air specialist of which some I thought were full of hot air.

Google “air movement in buildings, etc” and you’ll see it is a very large subject. As an old builder and older guy I have long thought the sick house syndrome had a lot of merit. We build buildings so dam tight now somebody sneezes on the 41 floor and their germs are spread throughout the building in 10 seconds. Anyhow, I find it a very interesting subject.

I did some experitmenting today Closed all windows and doors Fired up furnace Went looking for some cracks in the walls. Low and behold black soot or coal dust was coming thru the wall (crack) Wiped the arae down about 10 minutes dust had started to form. Going to suggest getting fresh air intake/vent for the furance
Thanks for the help

Originally Posted by Timothy M. Barr

I did some experitmenting today Closed all windows and doors Fired up furnace Went looking for some cracks in the walls. Low and behold black soot or coal dust was coming thru the wall (crack) Wiped the arae down about 10 minutes dust had started to form. Going to suggest getting fresh air intake/vent for the furance
Thanks for the help

Tim,

That's what I was talking about.

Good for you.

Now, think of all that coal dust in those walls ...

But I would not suggest a fresh air intake for the furnace, that is only potentially going to mask the problems, I would recommend the building be evaluated by someone knowledgeable in building science and test the entire building, making recommendations for what needs to be for the building AS AN ENTIRE SYSTEM.

Originally Posted by Timothy M. Barr

I did some experitmenting today Closed all windows and doors Fired up furnace Went looking for some cracks in the walls. Low and behold black soot or coal dust was coming thru the wall (crack) Wiped the arae down about 10 minutes dust had started to form. Going to suggest getting fresh air intake/vent for the furance
Thanks for the help

Sounds like the blower from the furnace is depressurizing the main floor of the building.

You've either got serious duct leakage issues and/or pressure imbalances due to unbalanced airflows.

Originally Posted by Jerry Peck

But I would not suggest a fresh air intake for the furnace, that is only potentially going to mask the problems, I would recommend the building be evaluated by someone knowledgeable in building science and test the entire building, making recommendations for what needs to be for the building AS AN ENTIRE SYSTEM.

Agree with Jerry, to quote a friend of mine "You can't pressurize Swiss cheese."

Address the HVAC deficiencies and building defects first then move onto ventilation for the building.

So far the solutions have all really been guesses, and for the most they have all been wrong. For starters you need to know how older homes are constructed. The vast majority were framed in the balloon style with open walls from the top to the bottom.

Adding a fresh air intake will only mask the problem as Jerry said. Right now I would not recommend any solution. Why? Well, the proper solution will most likely be very extensive and fairly expensive.

If it was me and I really did not know what was going on, I would simply say so. This discussion board is great, but it does not take the place of experience and knowledge. Your client will have more respect for you if you say I do not know, verses being wrong.

I would then tell the client that I would try and locate a person who might be able to help me discover the problem and the possible solution.

Scott, David and the Jerry's are all correct. We all know it is a mess and there is BPM blowing actively all over the house. The owner can and should address the air movement systems in the house but my problem with all this is still, how are you ever going to clean this house up? If you have BPM in the balloon framing and interstitial spaces, it will keep coming out of there for years to come. Perhaps they can foam those stud bays up and do some airflow and pressure diagnostics but I would never recommend white carpet in this house. They should talk to their insurance carrier. This is sounding like decimal places adding to the price tag daily. If the insurance carrier takes this on, I'm sure they will subrogate to recoup their losses.

Personally, they may be better off blowing the house up and starting over because this could easily get into six figures.

I think your next move is to bail on this and make it someone else's problem ASAP.
Bob

Originally Posted by Bob Harper

but my problem with all this is still, how are you ever going to clean this house up?

I think your next move is to bail on this and make it someone else's problem ASAP.

Bob,

That is my concern also, and I think your last statement is a very important statement - NO WAY would *I* want to recommend anything other than to have it checked by the building science experts as they would also be able to address the clean up factor, which is likely going to be greater than the solving the problem factor.

Coal dust is cancerous (can cause cancer), it is not? How much and how long of exposure I do not know, but if that has been going on for 5 years, that could be a heath problem at this point.

Well, I don't know for sure if any source of carbon is a carcinogen but we do know prolonged inhalation can lead to Coal Worker's Pneumoconiosis (CWP). I think it takes a long term exposure to develop this. However, when you inhale coal dust, if it doesn't stick to the mucous and get washed back out by the cilia, it will implant and be there forever. That portion of lung parenchyma loses its function and and becomes nonviable tissue that no longer contributes to gas exchange much in the same way as silicosis or tuberculosis do.

Regardless, it ain't good for you.

I like the idea of bailing out. I can give the client what has been said here and let them make up their mind
Thanks guys you been a lot of help
Learned a lot this past week

Tim,

Be careful when you send the link. Be sure to tell them to come to there own conclusion. Nobody here has been there, seen pictures of the home or the substance you are talking about.

For all we know there might be several coats of high gloss paint on the walls which is less permable. Inside kerosene heater, candles, cooking, propane heaters, etc. can be the culprit and not coal dust. Owners or past owners are not always truthful and you need to take what they tell you with a grain of salt.

These guys on this board are good but they are not Psychic So call mythbusters