Air seasoning is a common method of moisture management in utility poles and is done de facto during pole storage prior to treatment. However, extended air drying prior to treatment encourages fungal attack and can facilitate establishment of decay fungi in poles before a protective preservative barrier is applied. This problem can be mitigated by proper air-seasoning methods coupled with heat sterilization of the pole before or during treatment. Limiting fungal attack during air-seasoning and eliminating colonization at some point during subsequent preservative treatment seems to be a recurring problem. This paper reviews prior research on air-seasoning of large timbers and poles, and uses recent data to discuss the issue. Recent examinations of in-service Scots pine utility poles in a European electrical distribution network found that a high proportion of pole cores (37%) harbored decay fungi. Subsequent investigations revealed that prolonged air-seasoning coupled with inadequate sterilization in the treatment process were the likely cause of the problem. These results along with follow-up investigations on the effects of sterilization via more post-treatment sampling confirm that pole sterilization is an effective method of reducing the prevalence of decay fungi and improving pole performance.

Download document (415 kb)
free for the members of IRG. Available if purchased.

Purchase this document