Fungal damages in Norwegian massive timber elements – a case study

ABSTRACT

Massive timber elements are new in Norway, but their use is increasing. More knowledge is needed regarding the moisture performance of massive timber elements. There is uncertainty regarding the need for vapour barriers or retarders, and construction tents are rarely used despite the elements’ sensitivity to moisture. Twelve massive timber cases from the Mycoteam database, evenly distributed between the construction phase and use phase, have been studied. The types and causes of damage are compared, and remedial measures studied. Examination was challenging, and long electrodes in pre-drilled holes were found as a feasible method for moisture measurements. Drying took place from one week to several months, depending on wetting and drying conditions. The main cause of moisture intrusion was insufficient protection from precipitation, either during construction or due to constructional errors. Fungal growth was observed in all but three cases, while decay was found in six cases. High moisture content within elements did not cause fungal growth if the surfaces were dry. Decay in outdoor exposed elements was mainly caused by Gloeophyllum sepiarium, whereas Antrodia sp. was most common in elements not exposed outdoors. More research is needed regarding fungal damage in massive timber elements in combination with other materials.

KEYWORDS:

• Massive timber
• CLT
• moisture damage
• decay damage
• mould growth
• moisture measurements

Disclosure statement

No potential conflict of interest was reported by the author(s).