New Homeowner Curious About Copper Pipe in Basement (w/ Photos)

[Frank roche]

Hi all:

New prospective homeowner going through inspection. House is over 100 years old but has been meticulously cared for. We were informed that there was an above-ground oil tank in the basement at some point but that it was removed years ago. However, in the basement is a thin copper pipe (picture 1). We traced the copper pipe into the basement cement (picture 2), where it disappears.

My first question is can someone explain why an above ground tank would have this copper pipe buried into the basement? What was the original purpose? Where was it going originally? My concern is obviously that there could be a tank buried underneath.

The last question concerns the purpose of the hex bolt found in the basement floor, approximately 10 feet from the end of the decommissioned copper pipe. My gut says that it's a wedge anchor, but I'm honestly unsure?

I appreciate any help or feedback you guys can offer. Thank you very much.

 

[Highbeam]

Sure looks like copper pipe for a fuel oil line.

 

[peakbagger]

Pretty simple, standard practice was to run the line from the bottom outlet of the oil tank to the oil burner so that it flowed via gravity to the pump integrated with the burner. The concern was that the copper line would get in the way on top of the floor so the line was poured into the floor to "protect it" Unfortunately, damp concrete over the years will corrode the copper and the oil could find its way under the floor. In many cases it was slow process that the homeowner did not notice and the line may leak for years or in other cases the homeowner would fill their tank in the fall and it would be out of fuel in few days. That heating oil under the slab would leak into the ground under the house and its a major environmental issue that can cost tens of thousands of dollars to mitigate.

Code now requires at a minimum that the line under the floor is replaced with a line coated with vinyl (usually orange) that is run above the floor. In other areas they require the tank to be changed out with double contained tank (Roth is the most well known brand, that is a plastic tank surrounded by galvanized secondary containment tank with a pop up alarm if the plastic tank leaks). In some case new steel oil tanks have a "double bottom" with a cavity and plug on the side that can be used to test if the bottom is leaking. Fuel oil is pulled out of the Roth type tank through the top and then run under the floor rafters to the oil boiler. In some cases there was return line from the oil boiler to purge air out of the piping but in most installs there is device call a Tiger Loop that can deal with air in the line. Those overhead installations without the TIger loop can be PITA to deal with if the homeowner lets the tank run dry.

In rare cases in older homes, the homeowners just ignored or did not know about leaks under the slab and some future homeowner gets a surprise as once an oil leak is discovered its got to be cleaned up. Some states put a surcharge on heating oil and have a clean up fund to subsidize the clean up of these leaks. In the majority of cases the oil system was replaced with natural gas and the copper was just cut off at the floor and plugged or in some cases just left there or tiled over. In some cases homes had buried steel tanks outside the basement and banks usually will not write mortgages unless the tanks are removed and the soil around them tested and cleaned. During the tight real estate market many homes were being sold "as is" and inspections were being skipped, no doubt some folks ended up with past oil leaks under the slab or in the yard.

When I built my house in 1987 they were still pouring lines in the floor. I ended up having a rigid PVC pipe poured into the floor and used that to pull the copper pipe through when I got around to installing a boiler.

For other readers who may still have heating oil,

Different states have different laws that may prevent the oil company from delivering oil unless the tanks and fuel lines have been upgraded. In others, heating oil tanks need to be replaced prior to a certain age. My parents dodged a bullet on their home, my mom mentioned she had smelled oil and found a few drops under the tank and had put a pan under it. It was a weekend so I told my parents to call the oil dealer first thing Monday morning. They sent a tech first thing and by noon they had brought a truck to pump the tank out and replace it. I did not see it taken out, but the tank looked perfectly good. When they removed it my dad was there and one of the techs took a screwdriver and stuck it in through the bottom of the tank without a lot of effort. In most cases if it leaks, everything in the basement has to be thrown away, any interior partitions/wall will need need to removed and if any oil got under the slab, a portion of the slab may need to be removed and any contaminated soil removed. In a friend's case, the state had to put in collection wells around a parent's house and pump and treat ground water collected from the wells and then treat it for over ten year until it tested clean.

Water collects in the bottom of the tanks over the years and rots them from the inside out. I have seen attempts to measure the tank bottom thickness but in my experience with industrial tanks, it is hard to find a thin spot as the corrosion is not uniform, it forms blisters at random locations and eats its way down. My tanks are getting old and I currently have a used Roth tank waiting for me to install. BTW the Roth type tanks take up less space than the standard 275 gallon steel tanks, they sit directly on the floor and are rectangular and sit taller.

 

[EbS-P]

If you aren’t familiar with fuel oil i suggest watching a few videos here of what you can get into. In my opinion it’s one of the an oil leak worst things a prospective homeowner could unknowingly buy them selves.

If I ever buy another house I will hire an electrician, plumber, and hvac tech in addition to the home inspector. I found so many things that the home inspector missed. In my opinion they only make sure the banks assets are protected not your pocket book.

https://youtube.com/@TankMastersEnvironmental?si=pikl5FE7Asf_1Wov

 

[maple1]

If my inspector didn't know what that was, I think I would be having reservations about their competence.

 

[Frank roche]

Pretty simple, standard practice was to run the line from the bottom outlet of the oil tank to the oil burner so that it flowed via gravity to the pump integrated with the burner. The concern was that the copper line would get in the way on top of the floor so the line was poured into the floor to "protect it" Unfortunately, damp concrete over the years will corrode the copper and the oil could find its way under the floor. In many cases it was slow process that the homeowner did not notice and the line may leak for years or in other cases the homeowner would fill their tank in the fall and it would be out of fuel in few days. That heating oil under the slab would leak into the ground under the house and its a major environmental issue that can cost tens of thousands of dollars to mitigate.

Code now requires at a minimum that the line under the floor is replaced with a line coated with vinyl (usually orange) that is run above the floor. In other areas they require the tank to be changed out with double contained tank (Roth is the most well known brand, that is a plastic tank surrounded by galvanized secondary containment tank with a pop up alarm if the plastic tank leaks). In some case new steel oil tanks have a "double bottom" with a cavity and plug on the side that can be used to test if the bottom is leaking. Fuel oil is pulled out of the Roth type tank through the top and then run under the floor rafters to the oil boiler. In some cases there was return line from the oil boiler to purge air out of the piping but in most installs there is device call a Tiger Loop that can deal with air in the line. Those overhead installations without the TIger loop can be PITA to deal with if the homeowner lets the tank run dry.

In rare cases in older homes, the homeowners just ignored or did not know about leaks under the slab and some future homeowner gets a surprise as once an oil leak is discovered its got to be cleaned up. Some states put a surcharge on heating oil and have a clean up fund to subsidize the clean up of these leaks. In the majority of cases the oil system was replaced with natural gas and the copper was just cut off at the floor and plugged or in some cases just left there or tiled over. In some cases homes had buried steel tanks outside the basement and banks usually will not write mortgages unless the tanks are removed and the soil around them tested and cleaned. During the tight real estate market many homes were being sold "as is" and inspections were being skipped, no doubt some folks ended up with past oil leaks under the slab or in the yard.

When I built my house in 1987 they were still pouring lines in the floor. I ended up having a rigid PVC pipe poured into the floor and used that to pull the copper pipe through when I got around to installing a boiler.

For other readers who may still have heating oil,

Different states have different laws that may prevent the oil company from delivering oil unless the tanks and fuel lines have been upgraded. In others, heating oil tanks need to be replaced prior to a certain age. My parents dodged a bullet on their home, my mom mentioned she had smelled oil and found a few drops under the tank and had put a pan under it. It was a weekend so I told my parents to call the oil dealer first thing Monday morning. They sent a tech first thing and by noon they had brought a truck to pump the tank out and replace it. I did not see it taken out, but the tank looked perfectly good. When they removed it my dad was there and one of the techs took a screwdriver and stuck it in through the bottom of the tank without a lot of effort. In most cases if it leaks, everything in the basement has to be thrown away, any interior partitions/wall will need need to removed and if any oil got under the slab, a portion of the slab may need to be removed and any contaminated soil removed. In a friend's case, the state had to put in collection wells around a parent's house and pump and treat ground water collected from the wells and then treat it for over ten year until it tested clean.

Water collects in the bottom of the tanks over the years and rots them from the inside out. I have seen attempts to measure the tank bottom thickness but in my experience with industrial tanks, it is hard to find a thin spot as the corrosion is not uniform, it forms blisters at random locations and eats its way down. My tanks are getting old and I currently have a used Roth tank waiting for me to install. BTW the Roth type tanks take up less space than the standard 275 gallon steel tanks, they sit directly on the floor and are rectangular and sit taller.

Thank you so much for this thoughtful and thorough response. I appreciate this very much.

 

[peakbagger]

Glad I could help.

I agree that heating oil tank leaks/failures can be a big issue in older homes but I think it is pretty rare but when it happens it is really bad. Sad to say some folks use it as hype to get some business. The heating oil and propane dealers in Maine are always going at it to get market share and on occasion the oil dealers hype houses blowing up from propane or gas while the propane or gas suppliers bring up leaking oil tanks to sway home owners to one fuel or the other.

 

[brenndatomu]

I'd rather deal with the possibility of an oil leak (not that hard to prevent if things are updated) than have a gas bill and the possibility of the house blowing clean off the map (along with half the neighborhood most of the time) like seems to be happening more n more in recent years...

 

[salecker]

Cleaning up a diesel oil spill is actually simple and cheap...
The goberments make it expensive and complicated.
Here if the contaminated soil stays on the property you don't need any permits to "farm" it.
All you need to do to "farm" it is get it spread out and in the sunshine.The sun evaporates the diesel or gas and after that the soil is good to go again.
Propane when it leaks,inside a home it's usually a huge explosion.
There was a house in Whitehorse that blew up,neighbor was killed.
Ya sure propane is safe