chinese drywall 13

[smwpe]

You may not be involved in this problem but it will attract some attention soon. If your firm does work in Forida then my advice is to be careful. This is not a simple lead based paint problem. To give you a perspective, the leading engineering university in florida recently conducted a seminar where the speaker was -----.

We have a commercial client who wants our advice.

Appreciate any comments.

 

[concretemasonry]

smwoe -

Are you a registered engineer (forensic or similar)or an "ambulance chaser"?

More detailed, "uncloaked" information would give more responses and specific replies.

Dick

 

[smwpe]

Dick;

I understand. This is a big potential problem which has hit the media yet.

Yes, we are licensed as a professional engineer in the State Of Florida.

If you have access to this web site service, then you know they screen everyone.

Let me know how we can help.

But now we are looking for some registered engineers to give some advice on how to procede wih advising our client.

All the best.

Sam

 

[concretemasonry]

The reason I questioned the interest is that not all "Chinese" drywall can be put into one category and it has to be identified and related specifically to the project. It is all not the same just because it came from the same country. China supposedly buys more Buicks than the U.S.

China makes the most violins in the world, the cheapest (imported wood from the U.S. and Russia) and also the finest (from native native Chinese spruce), so anything is possible and shotgun approaches always scare me even if I make money testifying.

It all goes to the specific product, the importer/marketer and the specifications of the product. Documentation is critical.

If your commercial client is a developer/builder or drywall contractor, get what information was collected in the purchasing/installation process. If none is available, the only choice is to tear out areas to see if there is identification. Trying to test for the air quality in a completed structure will not provide any accurate information because there are many other factors.

There are always errors in manufacture/distribution, but usually the back of the sheet gives clues. Some people build by the unit cost or availability and do not care about anything else. Any product with no information is a "tip-off" to possible intention to remain unidentified. Certainly builders do not do much testing or verification except for the rash of problems with buildings built during the lack of availability a few years ago.

Good luck.

Dick

 

[hokie66]

A status report on investigations conducted by the Consumer Products Safety Commission.

http://www.cpsc.gov/info/drywall/jul2009status.pdf

 

[Ron]

smwpe...we are doing a couple of "chinese drywall" investigations in South Florida right now. While there is a potential problem, much of the issue is fueled by ignorance and panic.

An example...I recently read a report by an IAQ "expert". He indicated that they had the drywall analyzed and found copious sulfur/sulfates. Well imagine that! Gypsum is calcium sulfate. One astute consultant stated that looking for sulfur in drywall is like looking for hay in a haystack!

There are no established criteria for chemistry. There are no protocols for testing. There are no objective methods of establishing criteria for rejection....the only thing we can do definitively at this point is look at the labeling on the drywall and see if it comes from China.

There might be some true issues with the drywall. If sufficient sulfides are given off as a result of the drywall, then some of the common manifestations are practical...blackened copper wiring, corrosion of metal features, damage to HVAC systems, and irritation to human sensitivity. There are other things that can cause these as well.

For instance, in Florida, it is common to find H2S in the water. In some cases, it is very high. I have seen corrosion of piping and peripheral items resulting from the "sulfur water" in Florida. This has to be ruled out as a cause before blaming the drywall.

Lots more unknowns currently with "chinese drywall" than knowns. Need to establish investigation protocols, chemical testing, physical exposure testing and air testing.

 

[dik]

You even have to be careful about the certification. We had a batch of bad pipe (1/10 the strength it should have been) that was certified as compliant to A53... and was supposed to have been hydrostatically tested... but the longitudinal weld failed at slightly over 100 psi... and some portions weren't welded at all...

Dik

 

[stanford94]

smwpe,

i am a florida PE. this has been in the media here for over a year now...

 

[bimr]

Another report:

http://senate.legis.state.la.us/Quinn/Topics/2009/KnaufTianjinDrywall.pdf

 

[GoldDredger]

60 Minutes did an expose on it last year I think.

 

[smwpe]

Thanks to all who took the time to respond.

This is the reason we support eng-tips.com.

One of the briefings we recently attended was a presentation of a testing device developed by DRYWALL SCIENCE, LLC, by Jack M Frost who is located in Ft. Myers, Florida.

There must be others who are working on this problem.

Appreciate any comments, good or bad.

Sam

 

[davefitz]

I have not researched this to the full extent, but here is my take:

a) as far as indoor air quality goes , and its relation to consumer health and corrosion of copper alloys- perhaps the least costly fix is to install air recuperators ( air to air heat exchanger) with a large flow of fresh outdoor air to ensure the concentration of H2SO3 is below some allowable limit. The problem may be exacerbated by tightly sealed homes.

b) US style wallboard plants utilize clean natural gas to dry the wet gypsum boards, but this would be a very costly option in China which has limtied supplies of nat gas . Instead, I think the problem may be associated with the chinese use of coal fired plant hot fluegas to dry the wet gypsum boards, and this flue gas has high, unscrubbed levels of SO3 in it.

 

[bestmd]

So Sam,

Did you get the answers you were looking for?

I've been monitoring the remediation throughout S. W. Florida for nearly 6 months now.

Mike

 

[davefitz]

The US CPSC ( consumer product safety council) has a website with several recently completed studies on this issue. It appears the release of the corrosive agents is a function of relative humidity in the house and the rate of air replacement , and of course the mfr of the wallboard. The corrosive effects and the health conmplaints seem to be focused on Florida and Louisianna ; review of homes in drier climates with the same wallboard resulted in few complaints.

 

[bestmd]

When I said I was monitoring the remediation, I should have been a little more to the point.

I work for one of the companies gathering samples and evidence for litigation. As well as standing behind demo crews documenting the drywall removal.

Homes are torn down to the studs. Only thing not removed is the exterior walls, roof and tiled flooring.

It's a mess!

Mike

 

[hokie66]

Who is paying the bills for this work prior to litigation? Who is being sued?

 

[bestmd]

Good question, tricky answer. And I'm "handcuffed" by most of it.

Up front, some of the home builders are footing the bills.

That is those who are still around or haven't re-organized into another name to protect themselves. But I only hear rumors of that.

Some homeowners (very few I suspect) are spending their own money to get it done.

 

[hokie66]

Usually, the lawyers take the "shotgun" approach and sue everyone they can think of. Have the material suppliers been joined? Are there class actions?

 

[bestmd]

Well, there are to approaches. The builders and the lawyers.

The builders, as I said previously, mainly the large volume builders are trying to be a little pro-active about it and take care of it themselves.

If the homeowner can not find the builder or does not want to work with the builder, they get a lawyer.

And your right, a lawyer may want to go after everyone who had any part of importing Chinese drywall. The thing is, even the lawyers have few choices to pursue.

A lot of the suppliers have closed their doors due to the building bust and the importers have pretty much disappeared. So their only recourse is to try to pressure the builder and the Chinese companies and exporters themselves. Good luck with that.

I think they have a few other avenues they can follow but each is costly.

Class actions suits due occur, I've read, but it is mostly against the builder in a community to try to force them into remedying the situation.

There is a federal judge who has been assigned to this case in New Orleans. He will preside over all Chinese drywall cases in the US. Here is a link to a pre-trial order:

http://www.laed.uscourts.gov/Drywall/Orders/pto5A.pdf

 

[bimr]

Is anyone checking the pH of the drywall?

It is well known that hydrogen sulfide gas may be produced when landfilling or using gypsum as alternate daily landfill cover, particularly in a wet climate. Several conditions are required, including a moist, anaerobic environment and a low pH. Hydrogen sulfide gas is toxic at high concentrations (~1,000 parts per million) and has a foul, rotten-egg odor.

H2S is a weak acid, donating two hydrogen ions in neutralization reactions, forming HS- and S-2 ions. In water, the three sulfide species, H2S and HS- and S-2 ions, are in dynamic equilibrium with water and H+ and OH- ions. The percent distribution among the three sulfide species depends on pH. H2S is dominant at low pH, the HS- ion is dominant at mid-range pH and S2 ions dominate at high pH. In this equilibrium situation, sulfide ions revert to H2S if the pH falls.


In water, sulfide can exist in three forms; hydrogen sulfide (H2S), bisulfide (HS-), and sulfide S-2. The sulfide species present is dictated by the pH. At pH values less than 6, hydrogen sulfide (H2S) dominates.