Roof Truss Installation

Timber roof trusses are prefabricated triangulated frames that form the roof structure of most modern houses and buildings.
Individual trusses are lightweight but become unstable until braced — they can topple like dominoes if one falls.
The truss erection method statement must define the sequence, temporary bracing, and fall protection for the installation.
Trusses must be lifted by crane and guided into position — manual handling of trusses at height creates extreme fall risk.
Temporary bracing must be installed immediately as each truss is positioned to prevent lateral instability and chain collapse.
Permanent bracing, binders, and diagonal braces must be fixed at the specified locations before releasing temporary restraints.
Workers positioning trusses at height must use harness systems or safety nets as fall protection throughout installation.
Wind is a critical hazard — trusses act as sails and can blow over during erection, particularly before bracing is complete.
Fire risk is extreme during timber truss installation — no hot works and strict housekeeping prevent ignition of exposed timber.
Only competent persons with experience in truss erection should lead the installation team and sequence the work.

Chain collapse	An unbraced truss falling sideways pushes every adjacent truss over — the entire roof structure collapses in seconds.
Fall from height	Workers positioning trusses at roof level face continuous fall risk until permanent barriers are installed.
Wind vulnerability	Unbraced trusses topple in moderate winds — erection must stop and temporary bracing must be secure before wind arrives.

Do

Don't

Follow the truss erection method statement and designed bracing sequence exactly.
Lift trusses by crane — do not carry them manually up ladders or scaffolding.
Install temporary bracing immediately after each truss is set in position.
Fix permanent binders and diagonal braces at specified locations before removing temporary supports.
Use harness systems or safety nets for all workers at roof truss level.
Monitor wind conditions and stop erection when winds make truss handling unsafe.
Enforce strict no hot works and fire prevention around exposed timber trusses.
Brief the installation team on the sequence, bracing plan, and roles each morning.
Check truss dimensions and identifiers against the layout drawing before lifting.
Ensure the wall plate or bearing surface is level and secure before truss placement.

DON'T deviate from the designed erection sequence or bracing layout.
DON'T manually handle trusses at height — use a crane for every lift.
DON'T leave trusses standing without temporary bracing, even for a few minutes.
DON'T remove temporary bracing before permanent bracing is fully fixed and checked.
DON'T work at truss level without fall protection — harness or nets are mandatory.
DON'T erect trusses in wind speeds that make them difficult to control.
DON'T allow hot works, smoking, or naked flames near exposed timber trusses.
DON'T start the day without briefing the team on the installation plan.
DON'T install the wrong truss in the wrong position — check every identifier.
DON'T load trusses onto walls that are not strong enough to support them.

See also: Timber Frame Erection Safety | Working at Height Hierarchy of Control

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