Archive for the ‘rottenegg odor’ Category

Taking a Look at Issues With Drywall from China by Michael D. Conley

ASHI Certified Inspector

Published March 2009 Issues with drywall and drywall mud from China have been around since the late 1990s. More recently, drywall from China is being linked to health and safety issues, with the critical focus on drywall imported and used during the time period from 2004 to 2006. This time period coincides with the height of the Florida construction boom, in tandem with a shortage of drywall manufactured in this country.

The jury still is out on whether or not Chinese drywall creates a health issue. It seems to some it does to the degree that they have to move out of their homes. To others, it’s an expensive nuisance that is affecting components in their homes.

While some involved in this fray claim the defective drywall does not pose health or safety problems, many homeowners are complaining about health problems that seem to occur only when they are in their homes. Preliminary investigation by the Florida Department of Health concluded that current emission levels from drywall testing pose “no immediate health threat.”

Nevertheless, homeowners who are exposed to the problem say otherwise. Health concerns and health problems reported include an array of respiratory problems, nosebleeds, irritated eyes and headaches. Of concern is the possibility that the Chinese drywall is emitting excessive amounts of hydrogen sulfide fumes and ammonia gas, which can cause extreme irritation, unconsciousness and even death.

One inspector I spoke with said the drywall smelled like spent firecrackers. What do firecrackers have within their mix? Sulphur and ammonia.

Knauf, a German company manufacturing in China, produced some of the Chinese drywall in question. Knauf Plasterboard, Tianjin Co. Ltd. of China maintains that its Chinese drywall is safe and homeowner problems must be from some other source. But I spoke with a local consulting firm that stated the Knauf plasterboard is, in fact, defective. Also stated was that the ASTM standard (ASTM C36) used for the product was out of date and no longer recognized.

The American Society for Testing and Materials (ASTM) explained that the C36 standard was replaced more than four years ago with “ASTM C1396.” The C36 drywall was produced in March 2006, two years after that standard was changed.

Standard 1/2″ and 5/8″ fire-rated sheets are the culprits and they are not properly rated for fire resistance. My market area appears to be at the epicenter of the drywall-from-China quandary. Port Manatee is where millions of board-feet of this drywall was delivered and distributed throughout Florida and other parts of the southeast.

One homeowner reported that her jewelry was tarnishing quickly. Another homeowner complained that his A/C coil was corroding after only a year or two. Other indicators of a problem include black copper wiring in the main service panel and doorstops that turn black or look tarnished. Television sets, computers, microwaves and refrigerators all have been mentioned as susceptible.

Until we learn more, home inspectors can look for the following:

Drywall installed from 2004-2006. This appears to be the time period during which most of the drywall in questions was installed, but inspectors should allow leeway on both sides of those dates.

To identify the drywall, find a place where the backside is exposed (e.g., in the garage or attic where there is no insulation). –

Look for the words “CHINA” in red ink or “KNAUF” in black ink. – Look for C36 stamped on the back or edge tape, if available.

Use your nose or listen to any complaints from the homeowner. Sample a number of electrical receptacles and look at the copper wiring as well as the A/C coil.

Currently, there are about 80 complaints pertaining to this drywall, and it appears there will be more in the future. Lawsuits are pending with homebuilders and the manufacturer. As to the final outcome, who knows? All we can do is wait and see.


I recently performed a home inspection on a home that has been vacant for some time now. Shortly after turning on the hot water faucets the odor became offensive. Rotten eggs and other descriptions would fit this well. This particular home is supplied with municipal water. This smells like a fairly common problem and is called hydrogen sulfide. If the smell is only from the hot water faucet the problem is likely to be in the water heater.
How is this hydrogen sulfide gas produced in a water heater?
A water heater can provide an ideal breeding ground for the conversion of sulfate to hydrogen sulfide gas. The water heater can produce hydrogen sulfide gas in two ways – creating a warm environment where sulfur bacteria can live, and sustaining a reaction between sulfate in the water and the water heater anode. A water heater usually contains a metal rod (sometimes plastic) called an “anode,” which is installed to reduce corrosion of the water heater tank. The anode is usually made of magnesium metal, which can supply electrons that aid in the conversion of sulfate to hydrogen sulfide gas. The anode is 1/2 to 3/4 inches in diameter and 30 to 40 inches long depending on the heater design.
Is there a cure?
1) Disinfect and flush the water heater with a chlorine bleach solution and sometimes hydrogen peroxide. This can kill sulfur bacteria, if done properly. If all bacteria are not destroyed the problem may return within a few weeks.
2) Increase the water heater temperature to 160 degrees for several hours. This will destroy the sulfur bacteria. Flushing to remove the dead bacteria after treatment might control the odor problem.
CAUTION: Increasing the water heater temperature can be dangerous.
Before proceeding, consult with the manufacturer or dealer regarding an
operable pressure relief valve, and for other recommendations.
3) Replace or remove the magnesium anode. Many water heaters have a magnesium anode tube, which is attached to a plug located on top of the water heater. It can be removed. Removal of the anode, however, may significantly decrease the life of the water heater. You should consult with a water heater dealer to determine if a replacement anode made of a different material, such as aluminum or zinc, can be installed.