[in Japanese]

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Preservative effectiveness of candidate fungicides for glue-line treatment was investigated using 4.0-and 5.6 thick lauan plywoods glued with melamin-urea formaldehyde resin. Non-weathered ply-woods treated with the following three fungicides were able to inhibit effectively the decay by a brown rot fungus Tyromyces palustris Murr. at active ingredient retentions shown in the parentheses : 4-chlorophenyl-3'-iodopropagylformal (0.6kg/m³ ), 3-ethoxycarbonyloxy-1-bromo-1, 2-diiodopro-pene (1.0kg/m³), and mixture of tributyltinphthalate and potassium iodide (0.24kg/m³+0.48kg/m³). Higher retentions of these fungicides were necessary to inhibit the decay by a white rot fungus Coriolus versicolor Quél. The enhancement of preservative effectiveness was recognized oftenly in any fungicide-treated plywoods after 3-month exposure to 60°C, followed by its decent after longer term exposure. Such a enhancement was found more oftenly in case of 90 repetitions of wet (6 hrs water soaking) and dry (60°C for 18 hrs) cycling than in 30 repetitions. It was probable that the amount of fungicides diffusing into veneer wood from resin adhesive was more than that of fungicide losses by liberating or leaching during a limited term exposure to 60°C.
From the results with preservative effectiveness after several weathering treatments, the first and second organic iodo compounds described above are considered to be the most promissing fungicide for glue-line treatment and the third organic tin compound is the next. However, improvement of curing condition should be necessary to enlarge the fungicide distribution into veneer wood of treated plywood.

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The decay factors in wooden windowframes of four schoolhouses, set in about 30 years ago, were examined. Average percentages of decayed volume in the underframes, verticalframes and overframes were 1.51, 0.60 and 0.19%. Some factors influenced on decay of windows were analyzed by a statistical analysis "Quantification 1". Five items of decay factors : aspect of window face, projecting length of eave, wethered slope of underframe, distance between the window face and the crown of garden tree, good or bad at opening and shutting were taken up for the analysis. The criterion variables were percentages of decayed volume. According to the "Quantification 1", one of the most influential decay factors in windowframes was the distance between the window and the garden tree. Contribution ratio of the five decay factors was 48.3%.
To examine the relation among some deteriorative phenomena of wood, the multiple regression anlysis among rating of paint peeling, cracking size, and decayed volume was carried out. High correlation between cracks and decay was recognized. Contribution ratio of cracks to decay was 51.4 %.
For preventing wooden windowframe members from decay, it is recomended to have a distance at least 1m away between window face and crown of garden tree, and to prevent surface cracks on wood.

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