Incredible Fire Resistance Values

The first serious issue that Dr. Erwin Thoma came across in Germany was fire protection. In the 1970s and 1980s, wood houses were not allowed to be built with more than one floor. It was believed to be too dangerous because timber would burn quickly. Dr. Thoma decided to attain a fire safety certificate at the IBS Institute. It is one of the best known institutes of its kind in Europe, and it has the largest furnace for fire testing in Europe.

A manager of the institute said, “It is a wooden wall, so let’s try to run the F30 test and see how it does.” This test examines whether a wall can withstand a flame of 1000 degrees on one side for 30 minutes. Dr. Thoma had initially claimed that although made of wood, Holz100 was a completely different structure and asked for them to examine how long the wall would last beyond F30.

In response, the manager looked at Dr. Thoma as if he were an idiot and replied, “I said F30”. Dr. Thoma insisted, and the manager replied, irritated: “Listen, I have been working at the Institute for many years, and I have tested everything one could test in the timber industry. You should be glad if it can even withstand the F30 test. It will definitely not last any longer.” Finally, Dr. Thoma offered to pay for every minute of the test and the manager agreed, shook his head, and started the test. After 122 minutes, there was a strange sound. It turned out that the tank ran out of oil.

Following this incident, the institute carried out the test at its own expense and in the end, Dr. Thoma received a F180 certificate. It turned out that after three hours of treating a Holz100 wall with a 1000 ° flame, the temperature on its other side rose only by 1.8° C. The same treatment of a reinforced concrete wall would have caused the temperature on the opposing side rise to 600° even after 20-30 minutes and everything would start to burn. Because of the heat, the concrete begins to crack in layers and release the rebar rods which then melt.

​It may seem unbelievable, but even a thick tree trunk thrown into the fire will often remain unburned, while the fire eventually fades and dies out. Only some of its surface will be charred as a result. When the source of fire disappears, the trunk stops burning as well. For wood to burn well, it must be cut into small pieces and surrounded by air. Today, Dr. Thoma's firm builds certified firewalls made of wood for industrial needs.