Are the scaffold boards you’re using in a safe condition?
The Health and Safety Authority
is concerned with an increased detection rate of sub-standard scaffold boards
in use on construction sites and in an increase in the number of accidents
involving sub-standard boards.
As per the Code of Practice for
Access and Working Scaffolds all boards should comply with the BS 2482 standard
(standard updated in 2009).
Boards manufactured to the
standard can be identified by a marking on their end bands. BS2482 requires
that the end bands are marked with the following:
•
Number and year of British Standard;
•
Identification mark of the supplier;
•
The letter M or V (mechanically or visually graded);
•
The word “support”, followed by the target span in metres up to which the board
may be supported;
• Where appropriate, the
identification mark of a third-party certification body.
The end bands also have an
important role in protecting the vulnerable end grain of the boards. They
should extend around the edges of the board by at least 150mm for 38mm boards
and at least 100mm for 63mm boards. The bands should be secured with three
clout nails into the end of the board and two on each edge. BS2482 also permits
the use of teeth formed in the end band or special long staples to secure the
end bands. Damaged end bands can leave sharp edges which can cause cuts when
handled.
Any scaffolding equipment,
including scaffolding boards, particularly if they have been in storage for a
period of time, must not be used unless inspected by a competent person and
deemed fit for purpose. It is vital that all scaffold boards are checked
regularly thereafter for damage, rot or any other feature which may reduce the
strength of the board. It is a legal requirement that all equipment used for
working at heights in construction is inspected by a competent person at least
every seven days and records of these inspections kept. BS 2482 provides
guidance and limits on the acceptability of defects in scaffold boards. Any
board which fails one or more of the inspection criteria in BS2482 must be destroyed.
Boards must be cleaned prior to
storage and inspection. Check for surface contamination of the board such as
chemicals or cement. If you can’t clean it and inspect it properly, then the
board should be destroyed.
The following is a
non-exhaustive list of some of the common defects occurring in scaffold boards:
Fissures (shakes, checks and
splits)
BS2482 sets a limit for
fissures on the face of boards of 225mm length, and 12mm or more in depth.
Careful attention should be paid to splits in the ends of boards which can be
partially hidden by the end bands, but may pass through the full thickness of
the
board.
Wane
The standard permits a limited
amount of wane (a rounded edge caused by the curvature of the log from which a
board has been cut). The limits on wane are 25mm on the face of the board, and
12mm on the edge of the board.
Mechanical damage
If the board is damaged to an
extent that will reduce its strength, or is likely to cause unsafe footholding,
or an injury whilst handling the board, then it should be destroyed.
In normal use a board’s top
face on one job may become its bottom face on the next job. Mechanical damage
may occur on the first job but the failure may not happen until the board is
turned and loaded in the opposite direction. The user causing the damage may
not witness the failure and is unlikely to be aware of the consequences of
their actions.
Common examples of unacceptable
damage include:
•
Broken or damaged end bands;
• Wood
broken from the edge of the boards which significantly reduces the
cross-section of the board;
•
Loose or broken knots;
•
Damage caused by being struck by the forks of a forklift truck;
•
Excessive cuts in the faces of boards caused by hand saws, circular saws or
angle grinders;
• Transverse cracks caused by
overloading.
Distortion
As scaffold boards are exposed
to all types of weather, the wood is exposed to sunlight as well as cycles of
wetting and drying, which can cause boards to distort.
A distorted board is a
dangerous board, as it can move in service. The standard sets limits on cup,
bow, spring and twist. If any board exceeds these limits it should be
destroyed.
Insect attack
If a board contains wormholes
or wood wasp holes or if there is an infestation of the timber then the board
must be destroyed.
Fungal Decay
Boards must be free from any signs of fungal decay or rot. Fungal decay, usually wet rot, is common in poorly stored scaffold boards. Wood is vulnerable to attack when the moisture content is over 20%. It can be detected by discoloration of the wood, which also becomes softer. Rot often starts at cracks or around knots in wood because these areas are wetter as water is retained in the cracks. The boards will also often smell musty. A decayed board loses weight and so will feel lighter than an equivalent sound board. Below shows two examples of decay.
In
the early stages of decay there is a minor loss in bending strength or
stiffness, but there is considerable loss in resistance to impact loads, for
example, a worker jumping onto a board, or lifting a heavy sill etc. In the
later stages of decay large holes filled with soft decayed wood appear. The
rotted wood has transverse cracks in the wood fibres and the material crumbles
easily.
Decay in your boards can be
reduced by storing planks properly when not in use. This is particularly
relevant in these economic times when large quantities of scaffolding may be
stored for longer periods of time.
Boards should be stored
preferably under cover and clear of the ground. Spacers must be used between
each layer of stacked boards to allow an adequate flow of air
around the boards to dry them
out.
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