engleski

THE INFLUENCE OF TYPE AND COLOUR OF COAT ON THE DURABILITY OF EXTERIOR FIR WOOD JOINERY

The L-joints which were made of home-grown silver fir sapwood and prepared according to EN 330, were used to establish the influence of coat type and colour on the durability of exterior fir wood joinery. The L-joint's surfaces were treated with two types of coats, and exposed for 36 months in Zagreb. The first type of coat was alkyd paint and the second was stain, both in three different colours; white, brown and black. The L-joints described in this article were not treated with chemical preservatives and were examined after 1, 2, 3, 4, 6, 12 and 36 months of exposure. The influence of coat type was decisive on the moisture contents, and permeability during exposure. Regardless of the period of exposure the L-joints coated with stain always had lower average moisture contents and a lower increase in permeability than those coated with the alkyd paint. It happened due to the well known stain vapour difusivity. The influence of the colours of the coats wasn't so expressed as the influence of coat type, but it was evident during almost all the exposure. Darker surfaces, particularly during sunny periods absorbed much more heat rays which caused accelerated seasoning, lower moisture contents and a lower increase of permeability. In this article only the moisture contents and permeability of the untreated L-joints are presented, and the complete results of the research are being prepared for publishing.

fir-wood (Abies alba Mill.); L-joints; exterior joinery; moisture content; permeability

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