During assessment of the ground contact stakes in the Norwegian test field, we have found that very often the first visual rot attack is in the zone of the stakes were the stakes have been in contact with each other during the fixation. These parts are usually light green, caused by the lack of light during fixation, compared to the rest of the stake surface, which has a darker colour. To investigate if light on the stakes during fixation can affect the durability of the treated wood, we started a test five years ago. CCA and ACQ treated stakes were tested according to EN 252. The stakes were treated with two retention of each salt, one for the Nordic Class A (HC 4) and one for the Nordic Class AB (HC 3). Before exposure they were fixed in 7 different climates: 1) "Normal" fixation (60% RH and 25°C), light day, dark night for 7 days 2) "Normal" fixation without light for 7 days, 3) "Normal" fixation with UV-Iight 24 hours for 7 days, 4) "Stem" fixation 95% RH and 90°C, for 2 hours, 5) "Cold" fixation 50% RH and 10°C, for 30 days, 6) "Dry"fixation 10% RH and 50°C, for 24 hours, 7) "Wrapped" fixation, i.e. each stake packed in plastic foil, 50°C and no light for 24 hours. The colour of the stakes varied from light green to black, depending on the fixation climates. The rate of decay after 5 years in field test shows no big differentiation based on the fixation in different climates, even for the lowest retention.

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