Copper plumbing question

[Chocaholic]

Will keep brief. Considering purchase of a house that is spotless. Owned by an affluent elderly couple who appear to be very meticulous.

But…I went into the crawl space which is fully encapsulated (heavy, white plastic). There was a dehumidifier in there that I don’t think works. Here’s why…

The copper and PVC plumbing seems to be coated with a brown wet substance. I assume it’s from humidity (S. Carolina) although it was not humid in there currently. Here’s my concern, much of the copper piping was turning green. In an outer room (with HVAC) the copper looked perfect and no brown liquid coating to be found.

I’ll have a plumber take a look, but wonder if the oxidation will result in leaks, etc. Appreciate any ideas.

[Bill Douglas]

The green doesn't corrode much off. I live on the beachfront and copper pipe has turned green decades ago and hasn't leaked.

What fun looking at a new house!!!

[Chocaholic]

Thanks Bill…here’s a picture the realtor took. Not sure what the brown goo is either:

[id10t]

Originally Posted by Bill Douglas

The green doesn't corrode much off. I live on the beachfront and copper pipe has turned green decades ago and hasn't leaked.

What fun looking at a new house!!!

On the other hand my copper pipes arent green but I had undiscovered pin holes, until ine morning we woke up to water in the dining room. Mold, water damage etc. 110k+ the rehab/remodel it triggered and we still need to do bedrooms

[Bill Douglas]

I think the brown goo is some sort anti corrosion stuff. Sort of like what you spray inside car doors etc.

[A930Rocket]

I’ve been building on the coast of South Carolina for 25 years, but have not used copper. Of course, everybody uses PVC piping for the waste lines. I’ve never seen brown goo on any PVC and never heard of spraying pipes.

If the rest of the copper looks good, maybe get an estimate when the plumber takes a look, to replace the copper. If the copper is sweating, and you replace it, maybe insulate it.

Edit. I see the brown goo on the Romex also. Strange.

[Alan A]

It’s on the wiring too. Was there a leak at some point?
Pull the insulation and check for mold.

Edit: Mold remediation is very expensive. Trust me on this.

[look 171]

I don't like the brown goo whatever it is? Nothing should be moist in there. Trouble starts with moisture usually. Looks like something is sweating and the run offs are only on the plastic parts where the lumber jsut sucked it all up?

[A930Rocket]

A few more thoughts…

Have somebody check the wood with a moisture meter.

Verify any wood in contact with masonry/concrete/block/etc. has a barrier or pressure-treated material between it and the wood.

I don’t know if it’s still applies, but it used to be anything within 18 inches of the ground, had to be pressure treated as well.

I see joist hangers. Check the condition of the nails see if they are rusty.

[Tidybuoy]

Originally Posted by Chocaholic

I may be wrong (and I'm not a plumber) but that sanitary T looks to be upside down.

[Chocaholic]

Appreciate all the comments. We backed out of the deal. Upon questioning, the seller admitted they had a mold problem “some time ago” but were sure it was resolved. Too many questions all the way around. Pass.

[john70t]

https://www.airmccoy.com/blog/2020/9/1/the-differences-between-copper-pipe-types-explained

There are different wall thicknesses K,L,M for pipe.