Allas Sea Pool

1 14 2019 | Fire protection

Ready-to-install fire protected cladding boards speed up construction projects

The demand for fire protected external cladding panels is growing because more and more multi-storey buildings are being built using timber. In addition to following the fire regulations, the designers and builders strive for a natural appearance as well as a smooth and cost-effective building process. Ready-to-install cladding products treated with a translucent fire retardant meet these requirements.



The wood product industry believes that the volume of timber construction will grow in the coming years. This trend can be seen, in addition to Finland, in many other European countries and North America. The growing demand is speeding up the development and availability of more complete timber construction products. 

Apartment building Puukuokka. Fire protected: Facade (Siparila Oy)

The use of wood is increasing most rapidly in public construction. Timber is used, in particular, for building schools, day care centres and nursing homes. More and more multi-storey timber buildings are also being built for residential and commercial use. Wood is also often used on the external and internal surfaces of buildings with frames made of other materials.


The fire classification system for buildings and construction products as well as fire safety requirements are constantly being developed. There are also national and municipal differences in the requirements. Awareness of fire safety among construction professionals has improved considerably, but they constantly have to absorb and apply new knowledge in terms of both planning and building.

Therefore, collaboration between different parties as well as advisory services are important. Sales Director Niko Eiserbeck from Siparila Oy, a company specialised in cladding panels, says that there is need for a manufacturer’s site-specific instructions. When the entire chain – from the fire retardant manufacturer to those treating the wood products as well as building designers, fire consultants and builders – knows what to do, the fire safety level of a building will remain at its highest.

Apartment building Tuomarinkulma. Fire protected: Facade (Siparila Oy)

Nordtreat advises designers and builders on the selection of fire protected products and, on request, provides samples of products treated with different tones. The certified manufacturers of fire protected wood products usually have the product design and tone approved in connection with the order.


Construction companies streamline their processes by demanding more and more complete products. The cladding boards manufactured at the Siparila factory have hidden nails in them and are easy to install. As the products are industrially treated with Nordtreat’s translucent fire retardant, no time needs to be reserved for further surface treatments at the construction site. Only the ends of the boards are treated at the site with the same non-toxic fire retardant that is provided together with the products.

Siparila’s cladding products are primarily made of spruce and they have a CE marking. For example, the treatment of cladding panels with Nordtreat’s translucent fire retardants meets the requirements of fire class B-s1,d0 and is done using a certified vacuum method. Delivery of standard cladding products usually takes places 4 to 5 weeks after placing the order.

allas2Allas Sea Pool. Fire protected: All wooden surfaces (Siparila Oy)

The fire protection treatment on each product type requires a separate certification and therefore the fire protection of different batten solutions, for example, has to be tested separately for each structure. Close collaboration with the manufacturer also speeds up the process here.


According to Niko Eiserbeck, natural translucent tones are preferred on cladding panels, fascia and barge boards as well as on wooden batten structures used to liven up facades. Customers wish to show the vibrant wooden surface, so light, yellowish and brown tones are the most popular.

Ready-to-install fire protected products speed up the construction process, but the manufacturing thereof requires competence. Wood is a living material that absorbs a varying amount of fire retardant during the several treatments required for a finished product. In order to meet the fire protection requirements and to achieve the desired translucent tone throughout the product batch, the products are, for example,
weighed between treatments. The level of fire protection is the most important
requirement, but also the tones occasionally have to be adjusted during the production process.

Apartment building Koukkurannankatu. Fire protected: Facade studs

Siparila has supplied wood products treated with Nortreat’s fire retardants to various schools and nursing homes and, for example, to Allas Sea Pool in downtown Helsinki as well as for the balcony walls and ceilings of apartment buildings in the Ranta-Tampella area in Tampere, Finland.


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