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Electrical Wiring in the Home/black soot above almost all outlets


QUESTION: I am looking at buying a home that was built in 1998. I'm Near Tampa Fl. Above almost all outlets in the house there is black soot and it looks like an elongated upside down V. I see  it coming out between the outlet and the cover and rises up in some places to almost a foot. It is not burned as it can be wiped off. They have said that lightning knocked out the intercom and that concerns me. The house was recently inspected for sale and we were told that nothing was found about electrical. When the inspection was done the furniture was in place so a lot of the outlets were covered. Another item is around all the walls between the baseboard and the carpet (that part that is always tough to get to with a vacuum because of the carpet tack strip)there appears to be a black discoloration like the same type of soot I think that is coming from the outlets. It's almost like there was some type of blowback from something, hopefully not some electrical short. HELP PLEASE what are your thoughts and what should I look for in an inspection? Should I get an electrical contractor in addition to a normal instector?


I could send pics if it would help.

ANSWER: Hello steve,
My name is Robert and ill be helping you today and in response to your question Pictures would be a BIG HELP, there are certain colors and formations that mean something to me and be fore i begin to speculate it would just be must easier and more definitive if you can get me pics.Ill be waiting... Robert

---------- FOLLOW-UP ----------

smoke detector
smoke detector  

Outlet in bathroom
Outlet in bathroom  
QUESTION: Robert Thanks for helping. I was able to get into the house today. Below are some pics. I feel much better. I opened the breaker panel and there was no melted wires or anything. I also looked in a couple of plug boxes and do not see anything burned. Please look at the pics and see what you think Did not see the soot near any switch plates only plug boxes.
The black comes off of the outlet covers easily but not easily off the painted areas.

Hey steve,
Ok just as i expected, Ok several things can cause this and in your case having this "black soot" at MULTIPLE locations leads me to believe its your HVAC system...that being said your probably scratching your head saying "what the hell" well let me explain what happens is you wind up having negative pressure and its causing a vacuum like effect pulling in dust and micro- organizims through the gap between the receptacle and electrical box now what you can do is remove the plates and insulate the gap or you can just chalk around the plate.Thats just 1 explanation and to confirm what i would do is turn on either the heat or air and go to one of the receptacles that you have or had soot and put a lit cigarette as close to it as possible and see if the smoke from the cigarette gets drawn into it and if you don't smoke use a match or candle and once lit blow it out and do the same.if you don't even have a forced air heating system or cental air conditioning totally disregard this whole explanation.

An interior wall draft can cause this as well so just b/c you may not have forced air heating or central air doesn't mean it can't happen so just use the test and solution mentioned above.

Transformers due to their heat generation plugged in for long periods of time will most DEFINITELY cause that.

As for the smoke detector goes That can just be a coincidence and a separate issue...THAT black soot can be caused from the heat generated in combination with the smoke detector and batteries.

I hope this sheds some light, Please keep me informed and should you have any other questions or concerns please feel free to ask.Thank you Robert.
P.S. please take a moment and fill out the survey it extremely helpful and helps me help more people.Thank you
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Robert Tomasulo


I am here to answer ALL your questions regarding anything to do with home wiring such as Switches, Receptacles,Lighting, Main Distribution Panels, HVAC, Thermostats, etc; if it has a wire and in your home I CAN ANSWER IT. Whether its as simple as "why do my lights flicker?" Or as complex as I would like to rewire my house im here to help, in addition i can offer advice on remodeling a kitchen or lighting up you back yard as well as offering troubleshooting on appliances.


I have over 17 years in the electrical industry including Residential, Commercial & Industrial, Im also a certified HVAC technician as well as a certified fiber obtic technician.I am currently employed by the New York City Transit Authority as the Senior Electrical Maintainer and serve as the Relief Foreman for the electrical maintenance division for the past 12 years.I also hold many certifications, licenses and certificates in my field

FOA Member(Fiber Optic Association) UTU (United Transportation Union) IBEW (International Brotherhood of Electrical Workers) HVAC/TALK (Heating & Air conditioning troubleshooting group)

5 years of technical school after high school in electrical installation and design sponsored by Local 3 (IBEW) As well as over 17 years of hands on in the field training and education, and till this day im still learning, Not a day goes by that i don't learn something and if i feel i didn't i will open up a book to insure I DO!

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