Chinese Drywall Corrosion Testing
Welcome to Matco Services, Inc.
MATCO Services, Inc. is a leading independent consulting, engineering, and testing firm specializing in the fields of failure analysis, inspection, corrosion, metallurgical engineering, cathodic protection systems, materials selection, and coatings.
MATCO has investigated a wide range of complex corrosion issues for major US and foriegn companies. Some of these projects include identification of microbiologically induced corrosion, corrosion investigations of historic structures, identification of corrosion contaminants in lubricants, and a wide variety of other complex corrosion investigations for aerospace, manufacturing, electronic, medical, and utility companies.
MATCO has recently developed a standard test method to positively identify Chinese drywall that has been found to cause corrosion of copper, brass, and silver components inside residences and businesses in the United States.
Background of Chinese Drywall Corrosion Issue
In the timeframe of 2004 – 2006 American importers imported Chinese-made drywall which was used in construction of homes throughout the United States. Drywall or sheetrock is a product composed primarily of gypsum (calcium sulfate). Some of this drywall imported during this timeframe exhibits chemical compounds which release sulfur-containing gases.
Residents and building occupants with tainted drywall have reported corrosion or tarnishing of copper and brass components inside the buildings. This includes corrosion of appliances (air conditioners, washing machines, dryers, stoves, etc.) and electronics (televisions, computers, etc.). Some occupants have even reported health effects; however no specific health hazards have been identified as of March, 2009.
The exact causes and full extent of this problem are not yet known, but it has been found that potentially thousands of homes and business in Florida, Louisiana, Texas, and California may have been constructed using corrosive Chinese drywall.
Is My Home or Business Affected?
Some preliminary signs of corrosive Chinese-made drywall are as follows (note that not all Chinese or foreign-made drywalls are corrosive and that these early indicators may not accurately confirm presence or absence of potentially corrosive drywall):
Source & Timeframe – If your house or building was constructed in the 2004-2006 timeframe and it is known that foreign-made drywall was used in construction, there is a higher chance that your drywall is corrosive. Foreign-made drywall sometimes has markings that identify it as such.
Smell – Some of the affected drywalls have a noxious odor which has been described as smelling like rotten-egg, burnt matches, burnt motor oil, or welding flux. The corrosive gasses emitting from the tainted drywalls are known to contain sulfur. Carbon disulfide and carbonyl sulfide have been positively identified as two of these gasses and others are suspected.
Visible Corrosion & Appliance/Electronic Failures – If copper and brass components inside your house or building exhibit a dark gray or black coating this may indicate sulfur-induced corrosion. Also, if you have experienced early failure of appliances (particularly air conditioners) or electronics, failure may have been caused by sulfur-induced corrosion of copper and brass components.
You may follow the Florida Department of Health Identification Guide to help determine whether or not you may have affected drywall.
MATCO's Approach to Testing for Corrosive Chinese Drywall
The State of Florida has paid for a preliminary study to determine the factors that make the tainted Chinese-made drywall corrosive to copper, brass, and silver. The Unified Engineering report descibes the tests performed and the test results. The report can be viewed by clicking the link above (5.4 MB zipped PDF file).
Many physical and chemical differences were identified between the corrosive Chinese-made drywall and American-made drywall. However, testing was inconclusive as to whether or not these physical differences related to the presence or absence of corrosive compounds.
MATCO Services, Inc. has developed a standard test procedure which identifies whether or not a drywall sample is corrosive to copper and brass. The test procedure does not rely on identifying physical and chemical differences between American-made samples and test samples, but rather it identifies corrosion characteristics directly.
The test is performed by forcing outgassing of a drywall sample in a chamber by exposing it to heat and moisture. A copper test coupon with a completely oxide-free and contaminant-free surface is exposed to outgassing products. The sample is then evaluated for miniscule weight change, change in appearance, and presece of sulfur corrosion compounds by energy dispersive x-ray spectroscopy (EDS).
I Want to Test My Drywall for Corrosivity…What Do I Do Next?
Remove one or more 3”x3” drywall samples. Note it may be necessary to test multiple samples as both American-made drywall and Chinese-made drywall may be present inside one building. (Drywall Removal Guide
Place in a sealed storage bag, package, and send to MATCO’s Florida laboratory for standard corrosivity testing. (Matco Shipping Label
Include payment and payment form along with the samples. Acceptable forms of payment are cash, money order, personal check, cashiers check, or major credit card (Visa, MasterCard, American Express, or Discover). Make checks payable to "Matco Services, Inc." (Payment Form
Cost for removal of samples and shipping to MATCO must be covered by the customer. Excess samples will be retained for a period of 45 days after conclusion of testing unless other arrangements are requested. Cost for return of excess samples must be covered by the customer.
All testing will be performed by MATCO Services, Inc. and its employees. All results will be reviewed by NACE International Certified Corrosion professionals.
Testing to be used in conjunction with personal or class-action lawsuits may require onsite sample collection and testing or additional consulting services. If testing for the purpose of litigation, the customer should contact MATCO directly by phone or email.