On-site wood fire protection treatment

2 24 2021 | Fire protection | Fire regulations | wood construction

Nordtreat develops high-quality fire protection of solid wood elements for on-site conditions

Fire protection treatment of massive wood elements, such as cross laminated timber (CLT), under on-site conditions and in accordance with the requirements of fire class B-s1, d0 requires special expertise. Nordtreat offers a fire protection treatment training system that enables creating a network of partners for the most important markets. These certified partners can specialise in on-site wood fire protection treatment. In Finland, the training has been piloted with Maalaamo MTW.

When the fire protection of wood products must be carried out at the construction site, it is not always certain that the required fire class criteria can be met. Adequate application and absorption of fire retardant requires precise management and documentation of both treatment conditions and the process itself.

Ultimately, it is a question of the safety of the building users. Carelessly implemented fire protection does not meet the required fire class, and therefore poses a significant safety risk. In such cases, in the event of a fire the responsibility may become very burdensome for the construction company that carried out the work.


Meeting the B-s1, d0 fire class requirements is often required for surfaces such as wooden facades, interior cladding, balconies and terrace structures. Similarly, CLT elements and other visible solid wood structures must also be properly fire-protected. If products are chosen for the job that do not meet the fire protection requirements, the fire protection treatment is carried out on structures when they have already been installed. In some cases, fire protection treatment is carried out on items such as panels on-site before installation.

According to technical manager Pekka Hurri of Nordtreat, fire protection of wooden surfaces is a demanding task in which the care and professionalism of those carrying out the work is put to the test. “The end result must function well in terms of the required fire-technical criteria. The even appearance of the treated surfaces is also important. Differences in tone or run-off marks must be avoided. Both of these requirements are influenced by factors such as humidity and temperature conditions, the amount of fire retardant applied in one go, the number of applications, the time required for drying, and the treatment method.”

When fire protection treatment is diligently scheduled and carried out in accordance with the instructions of the manufacturer and all the work phases are properly documented, it is easy for the fire authority to check the conformity of the treatment with the regulations. This also simplifies the processes and liability issues of the construction company responsible for the work. In doing so, construction contractors, developers and the authorities can be sure the fire protection is compliant with all the requirements.



Nordtreat aims to create a partner network of painting and surface treatment providers. This will enable construction companies operating in different countries to offer trained and authorised professionals for the use of NT DECO fire retardant to carry out the fire protection treatment on construction sites that meets fire class B-s1, d0.

“The demand for wood fire protection is constantly growing, so this is a great way for surface treatment companies and professionals to specialise and be competitive”, Hurri says.

For example, municipal wood construction projects such as daycare centres, schools and nursing homes are sites for which fire inspectors require a well-documented demonstration of fire safety. And when it comes to safety, construction companies must choose a reliable partner that specialises in demanding fire protection. This facilitates and speeds up both the implementation of the fire protection treatment and the approval procedures.


Maalaamo MTW, a painting specialist mainly operating in southern Finland, has been a Nordtreat partner for several years. The company specialises in wood and steel fire protection treatment and acoustic coatings for ceilings.

MTW has specialists in wood fire protection. They are trained by Nordtreat and usually work as a working couple. In this way, humidity, temperature and application volume measurements can be taken care of and precisely documented during processing. Among the fire treatment projects carried out by Maalaamo MTW is the treatment of the solid log structures of the Kanava school in Lempäälä, which were treated with NT DECO.

There has been no need to market the service, as news of it has spread rapidly by word of mouth. Trained fire treatment professionals are justifiably proud of their expertise, which directly contributes to the safety of people, properties and their contents.

In Norway, a similar service is provided by Firesafe, a member of Nordtreat’s partner network that is one of Norway’s leading fire prevention and fire consulting companies.


Keep on track about fire safety of wood products. Our newsletter provides you with the latest ideas and solutions.