Урок 4.7

Текст A

TRADA OFFICES, HIGH WYCOMBE, ENGLAND

There is office accommodation of up to three storeys in this building. The top two storeys are of timber construction and have stressed skin panel external walls, made of ply on softwood studs but, inside, have a timber framework using hardwood columns and joists. There is a basement storey below this which is of brick construction.

As the site slopes towards the north-east, the basement storey occupies only that part of the plan area on the north-east side. The timber ground floor above this occupies the full plan area and is supported by 200 x 100 mm exposed hardwood beams on the long south-west and north-east sides and by a reinforced concrete retaining wall which provides a line support in the middle. The hardwood beams, at the back rest on concrete filled pipe sections and at the front, on the basement brick walls. The hardwood joists of the first floor and roof are supported by 600 or 750 mm deep beams at window head level on the long sides of the building and by a line of hardwood posts and beams in the middle. The panel beams are nailed on to the wall panels below and covered on the outside by a horizontal band of wood boards. All panels use ply, only 9.5 mm thick, nailed and glued to 50 x 75 mm softwood studs. The joints between the wall panels are covered on the outside by softwood vertical strips. Ventilation ducts and other services run in a suspended ceiling in the corridor. Because of the difficulty of providing a flat ceiling soffit with long span beams, softwood battens are nailed to the underneath and provide a fixing for the ceiling boards as well as space for wiring. A polythene vapour barrier is provided on the inside of the wall to prevent condensation within the wall which would reduce the insulation value and could lead to high moisture content in the timber.

The post and beam construction on the middle line takes gravity loads but no wind loads so that only simple beam-to-column connections are required. The wall panels take the remaining gravity load and all wind loads. This arrangement provides clear space inside and is a good strategy against fire as well; the post and beam frame is of thick section and protected by charring of their surface while the more vulnerable but less heavily loaded panel walls still have their ply sheets and studs protected by mineral wool insulation and the internal lining board.

Notes:

beam-to-column connection балочно-стоечное сопряжение

char v. обжигать

condensation n. конденсация

insulation value коэффициент изоляции

lining board обшивка, облицовочная плита

mineral wool минеральная вата

ply n. зд. фанера

polythene n. полиэтилен