What are these black lines?

[garyl62]

My company just bought a couple buildings that had been used as rental units for the past several years. We will use them as a group home set-up to help people be self sufficient after completing some treatment programs. When I did the walk through in one unit I saw this black film on the walls and ceiling, but it only showed up on the wall where there were studs or trusses. The unit was basically clean except for these areas, but you could tell the people that lived there had a lot of grease or grim as part of their life. There was grease/oil spills on the deck leading to the front door, looked like they had thrown something that had splattered against the siding at one time, and the utility sink was very stained with black grim that looked like it had been part of the soapy water discharge of a washer and left residue on the sink. The other thing I noticed was that there was a 90+ furnace in the unit, but the PVC pipe for both the fresh air intake and discharge air had been removed so everything was being pulled from, and dumped into the basement right by the sink.

I didn't have a ladder so I couldn't touch them so I can't comment of that, but this was on the main floor of the unit and in the basement there was a little mold on the drywall in one room. None of the other units had anything like this.

Any ideas what it may be, what caused it, or why it only stuck to the wall where there was framing material behind the sheetrock?

 

[Woodtic]

I'm not joking, is it possible they had a meth in the place? The other thought is the 90% furnace discharging flue gas in the basement. That is very acidic,and humid gas. It could have leached up the walls through the returns in the walls. What does the ceiling in the basement look like? Have you pulled carpet back yet?

 

[Deleted member 10829]

I've had that happen before and my opinion is it is from candles burning all the time and/or cigarette smoke.

 

[snowdance]

I've heard the candle theory. I've also heard something about moisture where the studs are and then dust, etc... collects there creating the black marks.

 

[ezra]

have tred to prim it?
my first thought was meth also how do the alloy parts around windows vents etc look if corroded bad could be meth .if it is corroded keep your pie hole shut or U could be in for a world of hurt. it will have to be disclosed to every person who rents from u from now on.
that may not be a good thing in a 1/2 way house lol

we recently did a bunch of work in a house that the former owner did taxidermy in for 40yrs. man I don't know what kind of chemicals were in the air in that place but nothing stuck to the walls with out bubbling fish eyes including when skimming light with joint compound

 

[mtb1115]

I've had the black lines at a few of my rehabs and this is what I found:

Ghosting
Ghosting is a phenomenon that is generally seen during the winter months. Ghosting can be identified as dark lines on the drywall of ceilings and walls that outline the wall studs or the ceiling joists inside the living space. Even though insulation is installed between the joists themselves are exposed to the cold winter temperatures in the attic. Since the wood joists are not effective insulators, they act as thermal bridges. Consequently, the temperature at the underside of each joist (attached to the drywall) is lower than the adjacent sections of the drywall that are covered with insulation bats. The lower temperature along the bottom of the joists encourages the formation of microscopic condensation. Over time, the moisture will trap dust particles hat show up as shadow lines that outline the wood joists or studs.
To prevent ghosting, install insulation bats over the exposed ceiling joists. Ideally, the insulation should fill the spaces between the joists and cover the tops of the joists as well. The same holds true for the stud spaces; however, the fix would be more difficult.

The discharge from a condensing type furnace (90%+) is moisture rich and corrosive hence the pvc venting (as well as toxic) also there was a problem a few years ago with imported drywall from china being corrosive causing all meal like duct work, copper tubing and light fixtures to discolor or corrode.

 

[skutr]

I don't think there was a meth lab in the apartment. The staining on the ceiling and the walls is probably from candles, cigarettes, cooking greasy food, burning pizza in the oven, ect. The reason why it only shows up where the studs is because of condensation. The studs are in the vaulted ceiling and outside the interior heated space of the house and they transmit heat/cold from the outside to the inside. This causes a temperature difference which can cause airborne contaminents to condense. Wash the walls & ceiling with TSP & water, prime and paint. Connect the furnace intake & discharge and check that the range hood in the kitchen is clean and operates properly.

The oil/grease spatters on the deck and wall looks like someone took a frying pan of bacon grease and tried tossing it out the door and over the deck. Unfortunately the wind was in their face and blew it back at them and onto the house & deck. Nothing you can do about that.

You're right the staining in the laundry tub is from standing water from the washing machine discharge. The drain may be partially clogged and caused the washer discharge to back up into the tub. If you're washing clothes that are dirty from grease/oil and use a lot of soap this can leave a residue behind. A diesel or auto mechanic may have lived there. Have a plumber check the drain and clean it out.

Check the feet of the laundry tub (are they rusted) and can the mold on the basement drywall be explained by the tub overflowing? Is there a sump pump with a battery backup? Does it work? Are the gutters & downspouts plugged? Is the 2nd floor deck pitched away from the house?

Sorry for the long winded reply but I used to do house inspections.

 

[favoritos]

Who knows the reason for the intake and outlet running into the house, but that is likely the cause of your radiant points along the ceiling and upper walls showing mold. It is not a black film.

I'm guessing they had a small grow operation based on the copper line input to the sink.(that line ran a lot of water) It all adds up to someone keeping air from escaping and a lot of water running.

I'll be curious to see if you find out what did happen in that home.

 

[highhertel]

Who knows the reason for the intake and outlet running into the house, but that is likely the cause of your radiant points along the ceiling and upper walls showing mold. It is not a black film.

I'm guessing they had a small grow operation based on the copper line input to the sink.(that line ran a lot of water) It all adds up to someone keeping air from escaping and a lot of water running.

I'll be curious to see if you find out what did happen in that home.

I wonder where that copper line in the utility sink is running to. Notice the scum build up in the sink does not cover the entire perimeter of the sink tub, looks like maybe a pump or something was on the right hand side of the sink connecting to the line. Evident by the no-scum area of the sink.

HH

 

[garyl62]

Well thanks everyone. The debates can continue but I'll try to add a few more details and clear up some things along the way.

First this sink and copper line debate, the washer was on the right side of the sink with the discharge going into the right corner. That kept that area cleaner than the rest and I think the guy must have been washing greasy cloths with enough soap to produce dirty suds that built up in the sink and left the dirty residue on the left side. The small copper line is a condensate drain line coming off the high efficiency power vent water heater exhaust.

As far as the black lines, I think the ghosting, or condensation with dirt build up is a real probability. There was a lot of old cooking grease sitting around in containers so I'm sure they used something like a George Forman that could have put a lot of crap into the air. I would also bet the lack of exhaust pipe on the furnace caused "dirty" air to be recycled into the furnace and distributed back into the house. There were also several candles left behind so that added some smoke to the place. It didn't smell like someone had been smoking in there so not sure if cigarettes added anything to it.

The mold was just in one finished room in the basement. Probably due to poor water drainage, or some other source. That is the one thing that makes me wonder about some type of growing situation though.

Thanks for all the comments and help, when I told the guys at work I was going to post something they were all like "yeah right, you'll never get an answer to that question" so once again, the JD community came through!

 

[mtb1115]

I have seen a meth lab and grow house or 2, this is not one of them. Some people are just messy. A little elbow grease can go a long way but sometimes with drywall it can be quicker to cut out and replace with new.

 

[MZEMS2]

Kerosene heater residue....been there, done that.

 

[ezra]

I was in one bank owed ex grow house a few yrs back it was amazing what the renters did to a 8 yr old home . it ended up getting tore down.

 

[Woodtic]

The ghosting theory is a strong one. The only way to get the studs to leave lines is major humidity and or chemical reaction. The china dry wall is shot down by the other units don't have this problem. I would think all of the units where rocked at the same time? As Ezra pointed out,you may not really want to know the root cause. If you do,pm me your info. You can take air samples and dust samples and send them to a lab. The lab sends you every thing to take the samples,then you send the kit back to them for testing. We deal in suspect sick buildings. It's the old saying, " don't ask a question that you don't want the answer to". Clean the place up,repair the code violations and move on. Replace the carpet,it has to be unsafe. Kilns the sub floors and walls.

 

[Woodtic]

To add to the ghosting theory. If that unit has a bad vapor barrier and was in a negative air pressure due to major exhaust. You basically pull cold air into the walls,verses hot air leaking out of the house. The black slop sink isn't from dirty laundry. I come home from work looking like a coal miner some times. My slop sink and washer are still white? Just some more advice,don't wash your wifes unmentionables with your work cloths,after you have been working on the blast furnace at US Steel.She will throw all of them out,and won't show you the new replacement unmentionables for several weeks. lol I made that mistake only once. Paid the Victoria Secret bill,and no payday for me.......