WORK METHODOLOGY
1.0 Delivery, Storage And Handling
1.1 Exercise care to avoid damage during unloading and
storing.
1.2 If trusses will be stored on the site for an
extended period of the time before use, adequate provision should be made to
protect trusses against the effects of the weather. Protect trusses and
accessories from corrosion, deformation and damage while stored at site.
1.3 When lifting trusses, care must be taken to avoid
any damage of truss members and joints.
1.4 In general, lifting trusses is depending on its
length and shape. Sling truss from the top chord and sling should locate at
equal distance from the truss centreline.
2.0
Fabrication
2.1 Site
measurement should be done prior to fabrication.
2.2 All trusses
will produce by using same material.
2.3 All
the joints are connected with self-drilling screws. Truss members are fastened
by electrical drill without any pre punched holes in order to ensure good
quality of finish trusses.
2.4 The screws are self-drilling, self-locking
and coated to resists rust and corrosion.
2.5
Connection
shall comply with BS 5950 : Part 5 : 1987.
1.
Sizes
of the screws, diameter, d : should be 3mm<d<8mm.
2.
In
load carrying connections, at least 3 Nos. of fasteners should be used.
3.
The
distance between centers of fasteners should be not less than 3d.
4.
The
distance from the center of the fasteners to the edge should be not less than
3d. If the connection is subjected to force in one direction only which is such
as to cause shear of the fasteners, the minimum edge distance may be reduced to
1.5d or 10mm, whichever is smaller, in a direction normal to the force.
3.0
Installation
3.1
Erection
of trusses, including proper handling, safety precaution, temporary, bracing
and other safeguards or procedures are the responsibility of the contractor or
contractor’s installer.
3.2
Unless
noted otherwise, trusses shall be supported on external load bearing wall or
beam.
3.3
Truss
design assumes the supporting structure can resists the horizontal and vertical
load.
3.4
Exercise
cares and provides erection bracing required to prevent toppling or domino’s
effect of trusses during erection.
3.5
Erect
trusses with plane of truss webs vertical and parallel to each other’s, locate
at design spacing as indicated in the construction design documents.
3.6
Trusses
shall be anchored by L shape steel plate at the specify location. L shape steel
plate should be attached to the reinforced concrete beam by expansion bolt.
3.7
Purlin/batten
should attach to the trusses according to the spacing provided.
3.8
Trusses
should be placed in accordance with the truss layout plan. No amendment is
allowed without the notification of the Design Engineer.
3.9
Building
Material like bricks, concrete tiles etc should not under any circumstances be
stacked on the trusses.
3.10
Installer
should strictly follow the instruction, roof truss layout plan and shop
drawings given by Design Engineer.
3.11
Provide
proper lifting equipment suited to sizes and types of trusses required, applied
at lift point recommended by truss fabricator. Exercise care to avoid damage to
truss members during erection and keep horizontal bending of the truss to
minimum.
3.12
Erection
Tolerances : Space individual trusses no more than plus or minus 4 inch or
100mm from plan location.
3.13
Bracing
is to apply sufficient to the plane of the truss to hold every truss member in
the position.
3.14
Temporary
bracing is used during erection to hold the trusses until permanent bracing,
sheathing and ceiling are in place.
3.15
Permanent
bracing shall comply with AS 4440-1997 section 4-bracing.
3.16
Erections
of trusses, including proper handling, safety precaution, temporary bracing and
other safeguards or procedures are the responsibility of the contractor or
contractor’s installer.
