Page 79 - The City and Guilds Textbook: Plumbing Book 1 for the Level 3 Apprenticeship (9189), Level 2 Technical Certificate (8202) and Level 2 Diploma (6035)

Chapter 1 Health and safety practices and systems

Static tower scaffolds
This type of scaffold is constructed from individual Guardrail
tubular scaffold components using standard scaffolding
Working platform
clips, and strengthened by braces and ledgers (horizontal
scaffold tubes that the boards rest on). Access to the Vertical standard
tower via a ladder may be from the inside or outside Toe board
of the tower, but care must be taken to ensure that
Load-bearing couplings
the tower is not destabilised by leaning ladders on the
outside. Access ladder lashed
to scaffold
Scaffold towers should be designed to carry a load of
150 kg/m² spread over the whole working platform, in
Diagonal bracing
addition to their own weight. A special design will be
required for any tower that may be subject to extra Horizontal ledger
loadings from wind or materials on the working platform.
Horizontal transom
Proprietary static tower scaffolds
These towers are constructed with steel interlocking
sections that simply slot together. The sections are pre-
formed H-shaped welded units to give strength. These
scaffolds are easy to erect but are often expensive and
not as versatile as other static towers. Base plate
Sole plate
Foot ties
Static tower scaffold requirements Plan bracing
● Tubes must be straight. p Figure 1.45 A correctly erected static tower scaffold
● Tubes and fittings must be undamaged and free from
corrosion.
● The ground that the tower is to be erected on must be firm and even.
● Base plates must be used. Adjustable base plates can be used on ground that
has different levels.
● Sole plates must be used to provide even weight distribution if the tower is
to be used on soft ground.
● Any couplers must be load bearing.
● Horizontal members must be fixed to uprights, with the exception of
transoms (diagonal strengthening tubes) under the working platform.
● Towers must have diagonal and plan bracing built in.
● Foot ties or plan bracing must be fitted as low as possible.
● Working platforms must be close boarded.
● Overhang boards must not exceed four times the thickness of the boards and
must not be less than 50 mm past the support.
● Working platforms above 2 m high must have toe boards fitted at least
150 mm high.
● Working platforms above 2 m high must have guardrails between 920 mm
and 1150 mm high.
● Access ladders must be lashed vertically, preferably on the inside of the tower.
● The minimum base measurement for any tower is 1.25 m.
● When erected indoors, the height of any tower must not be greater than
three and a half times its smallest base measurement.

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