We exclusively use mountain larch (bot. larix decidua) from the Alps. It grows at a height of 1000 to 1800 m above sea-level and originates from sustainable cultivation.
We love wood as a natural material.Julian Richter sen.
However, there are different kinds of larch. The larch which we use for our production grows in the mountains at a height from 1000 m above sea level. Therefore, it has considerably better physical properties (and thus should actually be called larix decidua montania). The advantages of larch grown in the mountains (therefore slowly) are significant: fewer resin pockets, less cracking, tighter growth rings and, above all, increased durability.
Our wood supplier has been certified according to PEFC ST 2003:2012 since October 2001. Since 2015 our production is also certified according to the current standard. The certificate confirms that processed and treated coniferous sawn timber and log wood comes from sustainably managed forests. According to an official assessment, larch is a moderately rot-resistant type of wood, considerably more durable than, for example spruce and fir, however less durable than oak or, in particular, robinia.
Our mountain larches are felled in winter so that the cut wood can dry before fertile fungus spores appear which can lead to early decomposition.
During the natural ageing process of the tree, core materials are deposited in the wood. This corning is responsible for the rot-resistance of the mountain larch. Our employees recognise good corning from the red colour of the wood. Wood with close year rings is more resistant to rot.
Wood intended for inserting into the ground and for horizontal beams needs particularly close rings. Our poles have at least eight year rings in the outer two centimetres. We ensure that poles inserted into the ground and horizontal beams, have centred rings so that close ring wood lies near the outer edge. We do not permit a pith eccentricity of more than three centimetres.
Since 1989 we have manufactured much of our wooden play equipment from unimpregnated mountain larch.
Our play equipment made of unimpregnated poles of mountain larch stands as a rule on steel feet. For short vertical pole lengths we are increasingly doing without steel feet constructions. The end-grained timber surfaces are given an angle cut covered with paraffin wax to avoid absorption of water.