The problem of mold infesting buildings is bad and, it’s going to get worse. The reason why has been, for the most part either missed or overlooked by those who should know better.
In 2000, a black mold was discovered growing within numerous houses in the rainy part of the United States’, so called Sun-Belt.
The culprit is the ubiquitous dry-wall used in almost all buildings today.
Dry wall’s a sandwich formed of layers. The core of gypsum, is laid down as a dense hard chalk-like substrate. Glued onto the gypsum is a layer of ground-up paper (similar to but different from cardboard) forming an outer surface that makes the board easy to use, it has a finish paper laid on which is smooth. Gypsum board is cheap and as building material, it’s ready to be painted, plastered, &c., so has been readily accepted by the trades.
However, ever-present mold once it establishes a foothold in a temperate climate where high moisture is the rule, is almost impossible to get rid of. As an example, look at the number of products on the market designed to remove mold from bathrooms and such.
So inside the walls, moisture is trapped and humidity levels are high. Paper although not a perfect growth media, contains enough nutrients for the mold to grow on and as the mold develops it becomes self-perpetuating.
Providing a mold inhibitor is a temporary fix. And, improving air circulation will only spread the mold. One solution is to get rid of plaster board (dry wall if you like) and replace it with something else, as example, paneling. This is an expensive and time consuming process and a lot of houses built in the period 1950 to date will probably be torn down rather than try to remedy the situation.
Listen closely and you can hear lawyers gnashing their teeth as they plan their assault on the dry wall manufacturers, the after market and their insurers. FHA, Fanny and Freddie had better run for cover. This will make asbestos seem a minor issue by comparison.
Here’s a bit of background.
W. R. Grace had a major investment in ammonia and urea plants that took advantage of Trinidad’s abundant natural gas (if not used would it was flared.) Grace built the plants with the assurance of the Trinidad government that they would be given preferential treatment in gas pricing which of course went straight to Grace’s bottom line.
Under this environment, when Trinidad’s Prime Minister gave J. Peter Grace a call and said the island had a problem with mold at a Government owned particleboard plant; Mr. Grace volunteered to help. In his usual manner, JPG told the Vice Presidents in different divisions that he expected an answer within a week (but in this case he was a bit more generous and gave two weeks to sort it all out.) Accordingly, since the Agricultural Division in Memphis was the marketer of ammonia and urea it fell on L. L. Jaquier’s shoulders to get an answer. ( LLJ was a Vice President of Grace and member of the Grace Board of Directors.)
LLJ put together a task force headed by a New York Vice President, reflecting Grace’s commitment to the problem. The working group included a chemical engineer from the New York office, an accountant from Memphis’s Ag Division and a biochemist/chemist from Ag Division's Research and Long Range Planning.
Members were assembled in New York with little time for investigative research of the problem. However, a visit was made to a particleboard plant in Arkansas where Singer (of sewing machine fame) made particleboard for their cabinets. Singer’s particleboard was made with pine chips, mixed with glue and set into a dense stable “board” under high heat and pressure. Unlike wood, the board has certain advantages, as each piece is just like all the rest and lends itself to mass production. Still it’s not a perfect product.
In New York, JPG (having done his homework as usual, had three by five cards on each of the task force members) greeted each member of the task force by name, emphasized how much he appreciated dedication to the task at hand (perhaps with a hint that jobs might hang on the outcome), said what was expected, and then he was off to some other pot to stir. Members of the task force were left wondering who the masked executioner would be, should they fail.
In the grand scope of things, Trinidad, basking in the riches of oil and gas revenues had decide that the standard of living of its citizens should be improved and new modern housing was just the trick. But how to do this quickly and economically on an island that had very few resources. Eureka! Trinidad had bagasse, the residue from sugar cane processing, and since wood was in short supply on the island, why not make particleboard and use the board to construct housing for the people. What a grand idea -- and it worked.
A German engineered plant when up on schedule, turned out a beautiful product and the housing trade jumped at the opportunity to build with it. Happy people moved into their new or remodeled homes and Prime Minister was assured of continuing in his political role, but dark clouds (should I say moldy) appeared on the horizon.
Trinidad and the neighboring islands each year are in the path of tropical storms and each year substantial damage is done, however in the maiden year of the particle board venture, the area was spared damage. But something worse than physical damage was lurking. Houses built of particle board began to mold; walls and ceiling first spotted with small green or black splotches were soon overgrown and it spread! No one could live under these conditions.
At the same time, at the particle board plant, a new problem appeared. In typical German fashion, the plant was running at one hundred and ten percent of rated capacity and while initial demand kept inventory low, suddenly the storage building was full of beautiful product and over production meant that board had to be stored outside. When demand for the board didn’t improve it became obvious that the plant would have to be shut down with little hope for restarting. The plant manager, faced with this prospect, committed suicide.
Bringing in new management didn’t solve the problem. The first thing done was to burn all the board on site, and restart the plant. Soon the buildings and yards were full again. Trinidad’s Prime Minister was faced with three problems: angry homeowners, a plant that produced a product no one wanted, and unemployment of workers. He called J. Peter Grace for help as the new plant manager seemed unable to solve the problem.
Was the problem or problems, financial mismanagement, faulty production methods or was it the board itself? The task force accountant, poured over the books; all the numbers added up, not a single bit of chicanery was discovered The engineer discovered no specific problems; granted bagasse offers special handling problems but the Germans had addressed and solved them. Exquisite is the only way to describe the plant where stainless steel, electronic and hydraulic controls, and over-engineered equipment were the rule. Something must be wrong with the board.
A visit to local houses, now vacant, affirmed the problem. The only solution was to tear them down, since painting over the problem or massive doses of bleach didn’t work. (Replacement with more particleboard only delayed reappearance. But, why such a problem? It had never occurred in Europe or the United States or elsewhere for that matter.)
The solution actually was quite easy.
Regardless of how effective the sugar processing plant is in removing sugar residues (which after all, is what their business is), some traces remained. Then there was the matter of the pith which is the open cellular material within the cane. Pith is a finely divided material that lends itself to being used as a finish material to cover the board in the final processing. (Particleboard is made up in layers carefully built up. A coarse inner core has applied successive layers until the finish coat is applied. Each having been previously mixed with glue which hold the whole mass together. So residual sugars and easily broken down pith appeared to be a potential problem
Next addressed was the ever-present mold. While the mold could be identified and certainly there were mold retardants and other chemicals that could be used this probably would only be a short term solution (The plant manager had already prescribed a hefty inclusion of such a product in the board but because of the heat and pressure or perhaps for some other reason, it didn’t appear to be the solution.) The board manufacturer was just going to have to live with mold as everyone on the island already did.
Which brings us to the final ingredient; the glue used in the board. After an extensive discussion with the plant manager, it was found that the urea formaldehyde glue used was the problem. It is assumed that when urea and formaldehyde are mixed to form a popular glue used extensively, that not ever molecule of urea is bound up in a form that makes it chemically unavailable. The glue is formed much like a bit of chicken wire with urea providing nitrogen, which reacts with the formaldehyde to form a complex structure. But, as it turns out, is not chemically inert!
What to do? Find another glue that doesn’t have the same properties. The best candidate, a phenolic resin was not favored because of its cost penalty over the urea formaldehyde. But considering the problem, it was a cheap and easy fix. The phenolic resin deprived mold of its source of nitrogen and starved it into submission.
So the task force bid the tropical paradise of Trinidad-Tobago farewell, returned to stateside employment, and wrote a brief report that was well received. Actually, Trinidad found a easier solution to their problem by selling the plant to an off shore company with dreams of selling board to the other islands (Never did learn how this turned out.) Grace continued to make good profits on the nitrogen products and the taskforce members kept their jobs. Not a bad ending, considering the alternatives.
****
Joe Wortham’s Home Page, About Joe Wortham, Directory of Web Pages
Questions? Comments? [email protected]