Unformatted text preview: 4. Span rating is determined in lab tests. A board with a span rating of 32/16 may be used as roof sheeting over rafters spaced 32 inches apart or as sub flooring over joists 16 inches apart. Plywood, composite, and OSB are rated this way. 5. Preservative woods are specified so that the purchaser will know that is in the wood. It might mean that the wood has additives to help decrease its susceptibility to fire and attach by insects. 6. The most widely used types of insect resistant woods are redwood, bald cypress, red cedars, and white cedars. 7. Nails are the main choice for installing wood because they are fast, cheap, and inexpensive. Nails also require no pre drilling....
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- Spring '08
- span rating, widely used types, insect resistant woods