Chinese Drywall

I inspected a home today that was built in the 2004/2005 time frame. The AC evaporator coil had typical rust/corrosion; however the thin copper tubing on the evaporator coil had the black corrosion associated with tainted drywall. (see attachment). I have either seen all or none and that is the main reason for posting.

Ground wires on 5 sample outlets through out the home and metal parts, i.e. faucets, spigots, door hardware etc had no visible corrosion.

Unfortunately the refrigerator was brand new and the coils were clean.

Ceiling drywall markings over two livable areas of the home were National Gypsum which is not a Chinese drywall manufacture.

According to the latest guidance from the CPSC (March 2011), for homes built or renovated in the 2001-2009 time frame the Threshold Inspection is positive if there is Blackening of copper electrical
wiring and/or air conditioning evaporator coil and Mean ground wire corrosion
rating >2

Based on the CPSC guidance, this home meets the requirements for suspect tainted drywall and therefore meets the prerequisite for Step 2, “Corroborating Evidence”

Would you agree?

Hello Richard. First, those capillary tubes sure show a lot of
“patina” customarily associated with copper. There are areas that do appear to be blackening but, it’s very small and may be caused by something else and not necessarily tainted drywall. Also, I do believe that you’d be very lucky to find tainted drywall on the ceilings as from the information I remember at a meeting I attended last year, the drywall used on the walls and not the size used in ceilings have been found to be contaminated. I may be wrong and maybe someone will chime in and correct me. Neighborhood information is also helpful in determining. Are there other homes within the community known to be contaminated? Just a few things to think about. I would be very careful to draw any positive conclusions based on the little evidence you have provided here in this picture. That’s just me though. Thanks for posting and hopefully some others will contribute as well.


Thanks for the response Humberto. I believe you maybe thinking of the 5/8" sheet rock used in garage ceilings which has not been associated with Chinese Drywall.

You may be right. For some reason I thought I heard someone say they hadn’t found it in 1/2" only in 3/8" drywall? maybe I was mistaken.


The coils have some patina but I don’t think that is an issue.
Here are a set of 16 year old coils.

I agree with Bert. That’s a pretty big statement to go on the pic youv’e shown.

The 1/2" inch drywall imported from China was not rated for use on cielings on 24" centers. On 24" centers it must be a 1/2" made for that application or 5/8" drywall. That is why looking for it on cielings is a waste of time. Side walls adjacent to vaulted areas in the attic might help though.

Any idea how old that evap coil is? Don’t forget that high sulpur content water can off gas chemicals that can cause this too. Is there a well pump in the garage?

Err on the side of caution and be carefull how you word the report.

I some experience with this. I was threatened and a complaint filed on me by a person I did NOT do an inspection for. She relied on my report and then thought the home had contaminated drywall. My report specifically stated no visible contaminated drywall was visible at the time of the inspection.

She threatened, filed complaints on all of my licenses. DBPR sent out an investigator, found no evidence of contaminated drywall and dropped the complaints. They asked that I respond to her, even though she was not my client and I had never even talked with her.

We had Joe Ferry send her a letter and she went away(hopefully to get mental help). You can not be too careful.

John did your client (not the crazy lady) specifically ask you to., pay you for an inspection for contaminated drywall leading to that statement regarding it that you put in the report? I am asking because I generally disclaim this stuff.

Yes it was a drywall inspection, the house was thought to have it before I went in. I did not know but the listing said, “Chinese Drywall.”

After my report the new listing said, “No Chinese Drywall.”

When the Realtor realized she may be sued, she called me and asked me to defend her. I told her that I would not, but stood behind my report. No visible contaminated drywall.

They had a well with high sulfur content.

I thought as much. This is a catch 22 situation for us, while the photo provided did not exhibit what most of us would consider a classic case scenario, once we start down the path of considering it a possibility we owe it to ourselves to point it out. The costs to repair are so high and the stigma of missing it are buisiness killers.

On the other hand, labelling a property as having it without proof could be equally as bad. With consequences including liability to the current owner.

Report writing regarding this issue is critically important to protect the interests of all concerned.

People suck!

The 5/8" ceiling drywall, made in the USA may be contaminated, so it is NOT a waste of time to check it. I have found this on many occassions.
Also, you need to check more than 5 outlets. If you have reason to believe there is contaminated drywall, i.e. black coils, you should check one on each wall (minimum) until you find black ground wire. I have found it in one room on one wall.
You cannot only rely on black copper coils, especially if it is not conclusive.

Bruce Meyer
Florida Home Inspections
Ft. Myers, Fl. area

That is the problem, nothing is conclusive. You can only state with testing that there is elevated levels of contaminates. You can advise your client to do further testing. Some american drywall is thought to be problematic also, possibly from recycled drywall.

I find many inspectors call it out and they are wrong. The best step is identifying the drywall. I do like when I am asked to do the inspection and the drywall is labeled made in china. I does make life easy.

Well yeah, you can test it but you are not going to know by looking at it, I was referring to simply inspecting for the chinese stuff if it is on the cieling on 24" centers than it should be replaced anyway.

I know of NO American made drywall that is corrosive. There have been accusations, but I can tell you with certainty that they are not true. There ARE homes with American made drywall that have exactly the same type of corrosion, but it’s from high levels of sulfide in well water and aearators that don’t remove the sulfide.

I can also tell you with certainty that there are Chinese brands of drywall that are not corrosive. You can look this up on the CPSC web site and see which Chinese brands are known to be corrosive and which are not.

You may want to skip checking the receptacles altogether and go right to the easiest place to find the proof.
The pictures below are all from the same townhouse.

Going by the electric, you probably wouldn’t think the Chinese drywall was present. By the a/c coils, maybe. By the ceiling and wall drywall, definitely.

Until someone gives me proof, nothing is certain. Even drywall from Palatka Fl is listed as unknown the last time I checked. Are saying that no drywall has been recycled?

Eric, there is a Dragon brand drywall that is not included in the suspect list. I think it is listed by the year. 2006 I believe. I say that because I remember looking at the list from the CPSC website. I also found this particular drywall with no other “redflags” in a home I recently inspected.


If you look on the CPSC web site, you’ll find that Dragon brand is not corrosive. Your photos demonstate that it’s not.

Personally, I’ve observed more than one home with Dragon brand drywall that’s not corrosive.