3.4.2 Codes of Practice Reference Title BS 5268: Part 2 Structural use of timber. Code of practice for permissible stress design, materials and workmanship Structural use of timber. Code of practice for the preservative treatment of structural timber Structural use of timber. Code of practice for timber frame walls. Buildings other than dwellings not exceeding four storeys Code of practice for preservation of timber Workmanship on building sites. Code of practice for carpentry, joinery and general fixings Code of practice for flooring of timber, timber products and wood based panel products Doors and windows including frames and linings. Wooden doors BS 5268: Part 5 BS 5268: Part 6.2 BS 5589 BS 8000: Part 5 BS 8201 CP 151: Part 1 3.4.3 Publications British Wood Preserving Association (BWPA), Premier House, Southampton Row, London, UK. 4. PART 4 APPENDICES 4.1 Appendix A: Glossary 4.1.1 Bonding with Radio Frequency (RF) Heating The use of radio frequency is merely a means of obtaining heat to cure glue lines in wood-to- wood joints. It can be considered a source of heat, like steam and electricity, and is measured in the same units of heat and the same units of temperature that are used for any other heat source. The means of generating heat with radio frequency does differ from other sources. The electrical impulses or energy that are generated in suitable equipment are transmitted at very high cycles or frequency. Their passage through any mass results in some development of frictional heat, the degree dependent upon the electrical properties of this mass. In the case of wood which is a reasonably good insulator, considerable heat is realized. Radio frequency current, however, causes a uniform heating of wood, so that the centre is heated as fast and to the same degree as the outer surfaces. This is in contrast to other heat sources like steam where the heat migrates slowly from the surfaces to the centre. The result is that RF current gives a very fast uniform temperature rise, and this phenomenon can be used to advantage for certain applications. The radio waves in RF heating range in frequency from 2 to 30 megacycles per second, which is slightly above the so-called "broadcast range" of 0.5 to 1.6 megacycles per second. In radio broadcasting, the waves are transmitted from a generator to an antenna where they are broadcast indiscriminately. However, in the case of gluing equipment the waves are transmitted or confined between plates or electrodes, and thus are put to use as a heat source when some mass like wood is inserted between these parts. Page 16