2009 年 58 巻 4 号 p. 304-309
It is necessary to properly control humidity in crawl spaces using humidity control materials such as charcoal, sepiolite, zeolite, etc., because the spaces tend to become damp, especially for high airtight and high insulation houses. Furthermore, wood components in crawl spaces are often infested by the subterranean termites (Coptotermes formosanus Shiraki and Reticulitermes speratus (Kolbe)). Recently the more attention is paid to the less- or non-chemical methods for termite control, and as a non-chemical treatment, physical barriers using particulate materials have been practically used in a few countries. In this study, in order to examine the feasibility of pelletized zeolites for a physical termite barrier with the ability to control humidity, moisture adsorption and desorption properties of pelletized zeolites and their penetrability by termites of C. formosanus were investigated. It was found that pelletized zeolites of 1.00 to 4.00mm in diameter showed the same changes in moisture content during adsorption and desorption processes as those for crushed zeolites, which were about four times as large as that for pelletized stones used as a physical termite barrier. In the penetration test of termites, the layer of pelletized zeolites with 1.40 to 3.35mm in diameter prevented termites from penetrating. These findings suggest that it is feasible to use pelletized zeolites as a humidity control material for crawl spaces and a physical termite barrier.