Pikku-Paavali 日护中心

The design of the Pikku-Paavali children’s day-care centre is based on local building history, the urban fabric and the need for healthy construction.

The client wanted a wooden building with good indoor air, which was later specified more precisely as a log-con­struction building. From a technical point of view, the functionality of this massive, wide-span log building was ensured by careful design and a com­mitment to annual maintenance.

The day-care centre, which is in the centre of Pudasjärvi, is bounded by Pu­istokatu and the pedestrian and cycle­way running at right angles to it. The courtyard is divided into separate areas for children of different ages by wooden fences and the children’s entrances are from the courtyard.

The main entrance opens via a lob­by into a lofty assembly room used for shared events, physical exercise and cel­ebrations. The orange roof, panelled in fibreboard, looks rather like a tent.

The plan is made up of close-cut, rec­tangular log frames which together form a labyrinthine structure. The building contains nooks and crannies which the children can take over as exciting out­posts that then become their own fa­vourite places.

External walls and partitions on the ground floor are all in log-construction. The quiet room also has internal clad­ding to guarantee the necessary sound insulation. Wooden surfaces are finished with wax or with a whitish wood-pro­tective treatment. The assembly hall and lobby are finished with white Saima hardwood flooring.

Office and auxiliary spaces on the up­per floor are built into the roof construc­tion above the top layer of logs. Circula­tion to the upper floor is via a stairwell clad in coniferous plywood.

Externally, the logs are treated with a translucent red finish. The solid-wood window and door frames are installed in the log construction without using cover fillets, the detail first having been tried out with a specimen installation and wa­ter-penetration tests. In terms of ener­gy-efficiency, the log-construction build­ing without separate insulation is in the low-energy class.

The pitched roof, clad in patterned felt, protects the building and the porch­es over the entrance doors. The architec­ture has been inspired by the brick archi­tecture of Pudasjärvi Town Hall and the local summer cowsheds built in wood.

Construction

External walls are built of 275-mm lam­inated logs, while load-bearing parti­tions are 275 or 135 mm. The structur­al frame is the same height throughout. The grain runs in the same direction in all laminations in the same log. External corners arew close-cut in the Tyrolean style. Partitions are connected to the ex­ternal walls using dovetail joints.

One of the problems of log construc­tion is the differential vertical compres­sion between external walls and parti­tions, which leads to differential drying and shrinkage. The log manufacture re­solved the problem by using extra glu-lam beams on top of the load-bearing partitions. The beams are supported on steel tubes, which can be adjusted for height and which are housed into the load-bearing walls.

The computerised robots on the log-manufacturer’s assembly line made it possible to cut the housings needed for the steel tubes into the logs at the factory. This eliminated problems caused in the roof structure by differential shrinkage between external walls and partitions.

The walls on the upper floor are in studwork and horizontal parts of the intermediate floor are in LVL. The en­trance canopy, which is made up of LVL frames, is independent of the log con­struction. The load-bearing roof struc­ture consists of more than one hundred prefabricated gang-nail trusses.