Under proper conditions wood constructions can last for centuries. However, wood can be seriously damaged by bio-deterioration, if conditions exist that permit the development of wood-degrading organisms. The main organisms that can degrade wood are fungi and insects. Although wood-degrading organisms may be environmentally necessary in order to "recycle" wood in nature and thus help to maintain a healthy lifecycle in our forests, wood-degradation by organisms poses a serious threat to timber construction.
In general, Laminated Timber is manufactured from spruce. Unfortunately, spruce is not very resistant against bio-deterioration and protective measures as for example moisture control and protection against wood-degrading organisms are very important. Microorganisms such as fungi need organic material to live and wood offers the proper food supply for these organisms. As the growth of fungal decay depends primarily on moisture and oxygen, and fungal decay needs wood with a moisture content of at least 25%, moisture control can considerably improve the durability of wood. The durability of dry or dehumidified wood can last for centuries.
Unfortunately, preservative treatment may not be very helpful for spruce because the impregnation can not permeate very deep into the wood and the interior of the cross-section is not protected. In this case surface coatings may only make sense as a temporary protection, if the wood is subject to wetting during construction.