Exo-thermic permeation. Fancy words! How effluent is your English?
One of those things I have picked up along the way is a way to tell if there has been abuse of cast iron drain lines. When it happens it is usually when people have septic systems. I learned it from a client who was a water-treatment expert. He worked in the field!
What is exo-thermic permeation? When septic systems back up an old clean-out technique, which my client called an "old wive's tale," is to pour hydrochloric acid into the system. But too much acid has the effect of causing cast iron to heat up.
Cast iron joints were sealed together by melting lead and pouring it into the joint. It would be drawn in, much like sweating a copper plumbing joint, harden and last forever! A tamping tool would situate and smooth it out.
According to my client, if there are back ups in the system, and that acid sits in the pipes, they heat up and sweat. That sweat permeates through the cast iron, and the lead, and looks like leaking. But touching it nothing is wet. It feels like it is oozing and dripping grease.
The drips can be cleaned up, but the more the acid is used the more the pipes will sweat.
UNTIL THIS INSPECTION I HAD NEVER SEEN WHAT I SUSPECTED TO BE "EXO-THERMIC PERMEATION!"
Not long ago, during a home inspection, I noticed three things:
1. The drains in this house were all slow. Everywhere in the house. Water would drain, but slowly. And the toilets were lazy, for lack of a better word.
2. The basement room where the drains all met had a freshly painted floor.
3. There were four cast iron joints and they all looked like this:
Thinking (but not really knowing!) this might be exo-thermic permeation I suggested that to my client. I also said that the septic tank needs to be pumped to see if the system is functioning, and/or the connections to or from the tank are bad.
My report also said that since this was a three-bedroom house the tank would be 1200 to 1500 gallons. If it wasn't working properly, and the water very acidic, the effluent would be floating on the top. The only way to tell if the tubes are all intact is to pump the tank and find the distribution box, EVEN IF MY CLIENT HAD TO PAY FOR THAT HIMSELF!
The seller was "offended" that I would suggest any problem with the system, that it worked fine and yadda, yadda. And that there was no reason to paint that floor under the connections except "to make it look nicer."
Yesterday the realtor and my client spent most of the day trying to find the box and distribution system and dig it up to see what's up. He called me to tell me that I should see this before they pump it out! I rushed over!
Obviously this little puppy isn't working! What you see on the left is floating effluent. The tank has not treated it to convert solids into a liquid for system percolation. You can see that the "T" has been broken for some time.
The photo on the right is the connection between the tank and the distribution box. By the time I got there the distribution box had been replaced, but the connection to it is broken and has not worked for some time.
Standing there with everybody I said it looks like there really was exo-thermic permeation and too much acid in the water. The tank isn't working because there is too much acid.
The septic tank guy, impressed, looked at me like I was a Martian, saying, "You know about that?"
Now the entire system needs to be tested by a specialist to see if the field percolates effluent! I bet it doesn't!
My very happy client was saved thousands of dollars. And maybe more to come if the field doesn't distribute effluent properly!
My recommendation: in an older house with cast iron pipes, look for exo-thermic permeation! Just suggesting the word will make you look really smart! And what you say likely won't be bull effluent!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560