COSP Tube & Clamp


Tube & Clamp Scaffold

The following are some common sense rules designed to promote safety in the construction of scaffolding. These guidelines do not purport to be all-inclusive or replace other additional safety and precautionary measures. They are not intended to supersede the requirements of any provincial regulations, codes and ordinances. The user shall be responsible to comply with all recognized provisions. Where possible, post the Code of Safe Practice in a conspicuous place and ensure that all persons who erect, dismantle or use scaffolding are aware of these. It is recommended that these instructions are the subject of tool box meetings.


Workers  must  be  properly  trained  or  instructed  before  they  use  equipment.  Only competent workers may construct scaffolds.


Inspect all equipment before using. Never use any equipment that is damaged or defective in any way.


When possible, always survey the job site to identify any potential hazard condition. Complete jobsite hazard evaluation and amend your standard fall protection plan with site-specific requirements.


Never construct a scaffold on unprepared foundations. Where necessary, provide adequate continuous wood sills and ensure that they are not less than 50mm x 250mm (2” x 10”) and cover two frame legs in length. Footings, sills or supports must be capable of supporting at least 2 times the maximum load to which they are subjected without settlement. Any part of a building or structure that is used to support the scaffold shall be capable of supporting the maximum intended load to be applied, and must be verified by a professional engineer.


Always use base plates and ensure that these are cantered and spiked to the wood sill.


The spacing of standards is dependent upon the loading to be imposed on the scaffoldAlways check loading requirements and, if necessary, seek approved engineered drawings. Ensure that standards are located securely on base plates and are plumb.  Joints in stan- dards should be made with End -to- End or internal spigot clamps, and where possible, should be staggered so that they do not occur in  the same level.


Connect the ledgers to the standards with right angle clamps and ensure that they are level. Joints in ledgers should be made with End-to-End clamps only, and should occur as close to the standard as possible, and should be staggered in alternate bays.  The vertical spacing or lift height between ledgers should not exceed 1.98metres  (6’-6”).


The transoms should be connected across the ledgers with right angle clamps, preferably at the standards, or within 300mm (12”) of the standards and should not extend more than 225mm (9”) beyond each ledger.  Special design consideration should be given to any tran- som that is longer than 1.52m (5’-0”) and is supporting a load.

BRACING – Internal (a)

Install internal or standard-to-standard bracing every 6m (20’-0”) in length, and ensure that they are connected to the standards as close as possible to the node point (where ledger meets standard) by swivel clamps. If bracing is connected to the ledger, right angle clamps must be used.  Internal bracing must extend to the full height of the scaffold.

BRACING – Sway (b)

Sway or façade bracing should be installed on the outside face of the scaffold to full height, and can be either in one single bay or extended across multiple bays. If single-bay bracing is selected it must be in both end bays and at least every 15m (50’-0”) longitudinally.  In the multiple-bay configuration, the desired angle is 45° to the horizontal, close to the node point, and this should be continuous to full height, and in many cases will be designed by an engineer.

BRACING – Plan (c)

Plan bracing (horizontal diagonal) is recommended and is often required. As a minimum, it should be installed at the base and on the same level as the scaffold ties.


Where the scaffold height exceeds three times the smallest base dimension (3:1 ratio), scaffolds must be tied at least every 4.57m (15’-0”) intervals vertically and 6.0m (20’-0”) horizontally. Where possible, push/pull ties should be used, ensuring that the tie tube is con- nected to both standards (or both ledgers near the standard) with right angle clamps.  Tie tubes should be installed on the same bay as the internal bracing.  If it is not possible to tie the scaffold to a structure, a professional engineer must provide special design considera- tions.


The work platform provides the worker with a safe environment from which to work.  The work platform must consist of a fully planked/decked surface and shall have guardrails consisting of top rails, midrails and toeboards installed on all open sides. Toeboards shall be installed at the edge of all work platforms and should be a minimum 100mm (4”) high.


Guardrails must be installed on all open sides of the scaffold where a person can fall a distance of 2.4m (8’-0”) or more, and shall be not less than 0.92m (3’-0”) nor more than 1.07m (3’-6”) above the platform, and should be positively connected to the standards. Midrails  shall  be  installed  equal  distant  between  the  guardrail  and  the  platform.


Always use select structural wood plank, LVL (laminated veneer lumber) or equivalent approved 50mm x 250mm (2”x10”) lumber, of uniform thickness.  Ensure that wood plank extends a minimum 150mm (6”) and no more than 300mm (12”) beyond the centre of supports and should be cleated at one end to prevent lateral movement. Wood planks should not span a length greater than 2.13m (7’-0”) unless engineered otherwise.


Most steel planks have a supporting hook and wind lock to prevent uplift. Ensure that the steel plank has a nonskid surface and that the load capacity rated by the manufacturer is not exceeded.    Always    ensure    that    the    wind    lock    is    in    the    closed    position.


These are normally constructed from aluminum side frames with a plywood or metal decking and are secured to the scaffold by supporting hooks with wind locks that prevent uplift.  The load capacity of these decks is rated by the manufacturer and should be clearly identified on the deck and must not be exceeded. Always ensure that the wind lock is in the closed position.


Ladders are used to gain access to the working platforms. Ladders, ladder cages and rest platforms, when installed on scaffolds, must conform to all applicable codes, and must extend approximately 1m (3’-0”) above the landing area and be secured. Always maintain 3- point contact at all times when climbing.


Manufactured modular stairways are used to gain access to working platforms and must be installed in accordance with the manufacturer’s instructions.


Cantilever platforms, except fabricated sidebrackets, must be designed by a professional engineer and shall be installed in accordance with sup-plier’s/manufacturer’s instructions.


The load on any scaffold must never exceed the safe working load that it was designed for. Most scaffolds are required to support at least four times the intended load, however this varies in different jurisdictions and must be checked. When any unusual loading conditions apply, or when the load exceeds 3.6 KN/m (75psf) the scaffold must be designed by a professional engineer.


If the scaffold has tarpaulins or any enclosure system attached, this imposes additional wind loading and the scaffold must be designed by a professional engineer.


It is dangerous to construct a scaffold close to power lines. Always consult the power company for specific guidelines and conform to all applicable codes.


In certain jurisdictions, unless a safety net or travel restraint system is being used, workers shall wear fall arrest systems if the workers may fall a distance of more than 3 m (10’-0”). NOTE: You must refer to the General Guidelines for additional information relating to this product group.