MOISTURE CONTROL
Wood is a 1) _____ material, which means it naturally absorbs and releases water to balance its internal moisture content with the surrounding environment. The moisture content of wood is measured by the 2) _____ of water as a percentage of the oven-dry weight of the wood fiber. The key to controlling decay is to control moisture. Once decay fungi are established, the minimum moisture content for decay to propagate is 22 to 24 percent, so building experts 3) _____ 19 percent as the maximum safe moisture content for untreated wood in service. Water by itself does not 4) _____ the wood, but rather, wood with consistently high moisture content enables fungal organisms to grow. The 5) _____ objective when addressing moisture loads is 6)_____ water from entering the building envelope in the first place, and to balance the moisture content within the building itself. Moisture control by means of accepted design and construction details is a simple and practical method of 7) _____ a wood-frame building against decay. Finally, for applications with a high risk of staying 8) _____, designers should specify durable materials such as naturally decay-resistant species or wood that’s been treated with preservatives. Cladding, shingles, sill plates and exposed timbers or 9) _____ beams are examples of potential 10) _____ for treated wood.
10 Fill in the gaps with derivatives of the words in capitals:
11 Fill in the gaps in the following passage with a suitable preposition given below:
Under microscopic investigation, softwoods show only one type 1) _____ cell which varies 2) _____ size 3) _____ the rapid growth 4) _____ spring and early summer (early wood) and the slow growth 5) _____ the late summer and autumn (late wood). These cells perform the food- and water-conducting functions and give strength 6) _____ the tree. Hardwoods, however, have a more complex cell structure 7) _____ large cells 8) _____ the conducting functions and smaller cells providing the mechanical support. They can be divided 9) _____ two distinct groups: diffuse-porous hardwoods and ring-porous hardwoods.
12 Puzzle out the crossword:
1. Деревянные части здания. 2. Рельеф. 3. Кирпич. 4. Электророзетка. 5. Выключатель. 6. Водопроводчик. 7. Оконная рама. 8. Сосна. 9. Герметичный. 10. Желобок. 11. Петля дверная, оконная. 12. Ручка дверная, оконная. 13 Look at the text, separate the words to make sense:
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