SMART Compliance

Summary of the Module

The Tied tower scaffolding compliance check module checks tube and fitting tied towers for compliance with TG20:21.

The tied tower compliance check is similar to the Independent scaffolding compliance check module but is limited to scaffolds of one or two bays along the length of the elevation.

The software produces a compliance report that states the site location, scaffold configuration and dimensions, whether the scaffold is TG20:21 compliant and, where applicable, the compliance criteria that must be observed.

If the scaffold is not compliant, the software can suggest options that may achieve compliance and avoid a bespoke design where possible.

Tied Tower Scaffolding Compliance Check Module

The Tied tower scaffolding compliance check module checks a tube and fitting tied tower for compliance with TG20:21.

All permitted TG20:21 compliant tied towers can be checked, with the scaffold drawing, dimensions, configuration and TG20 compliance criteria summarised in a report.

The checks are generally the same as those performed by the Independent scaffolding compliance check module, subject to the specific requirements and limitations for tied towers.

Scaffolding Supported:

  • Tied towers of one or two bays along the length of the elevation.
  • Scaffolding founded on the ground or on a permanent structure.
  • Supported TG20:21 load classes, platform widths and lift arrangements.
  • Brick guards, debris netting and sheeting.
  • Tying to an impermeable solid façade or a façade with significant openings, with the option to specify the tie capacity of the permanent structure where known.
  • TG20 compliant prefabricated structural transom units, including a check to determine whether ledger bracing can be omitted.
  • TG20 compliant Type 4 galvanised steel tubes, cold formed S355 galvanised steel tubes or hot formed S355 galvanised steel tubes.
  • Double standards, including an automatic check to determine whether they are required and, if so, the height to which they must extend.
  • A TG20:21 compliant pavement lift using one of the permitted stabilisation arrangements.
  • A light-duty cantilever fan fitted to a specified lift.
  • Inner edge protection options.

Current Limitations:

  • The tied tower is limited to one or two bays along the length of the elevation.
  • A bridge cannot be added because of the limited length of the tied tower scaffold.
  • Inner cantilever platforms are not presently permitted in the TG20 compliance check for a tied tower.
  • Rakers are not presently permitted in the TG20 compliance check for a tied tower.
Display Panel Options

The display panel options are the same as those available for the Independent scaffolding compliance check module.

Map

The module begins with a map view where you can select the site location. The site location is used to determine the potential wind loading on the scaffold.

The address can be selected using the map search or by moving the site marker. The site address is then populated automatically and can be manually overwritten if required.

3D Model

The 3D model provides a preview of the tied tower and updates dynamically as the scaffold inputs are changed.

You can rotate, zoom and pan the model to inspect the scaffold configuration.

2D View

The 2D view displays the scaffold without perspective and includes front, plan and side views. The drawings update automatically as the scaffold inputs are changed.

Site

The Site options are the same as those provided for the Independent scaffolding compliance check module and define the scaffold location and conditions used to calculate the wind exposure.

Site Details

  • Site details: The site address is populated automatically once the site location has been selected on the map. The address may be manually overwritten without changing the position selected on the map.
  • Consider sheltering from nearby buildings: Reduces the wind exposure by considering the sheltering effect of nearby buildings where the relevant wind sectors are within town terrain.
  • Design life: Select whether the scaffold is a temporary structure of up to two years or a long-standing/permanent structure.
  • Standing during: Select the spring and summer option to reduce the wind exposure for temporary scaffolds standing only between April and September. This option is available when the design life is set to two years or less.
Scaffolding

Select the Scaffolding tab to enter the tied tower dimensions and configuration. The display automatically switches to the 3D model, which updates as the inputs are changed.

Most of the scaffold inputs are the same as those provided for the Independent scaffolding compliance check module, with specific requirements for the tower length and tie arrangement.

Loading and Dimensions

  • Load class: Specifies the maximum permitted loading on the scaffold. Changing the load class automatically sets appropriate default values for the maximum bay length and platform width, which can then be modified where permitted.
  • Inside board load class: Specifies the loading applied to the inside boards in accordance with TG20:21.
  • Tower length: Specifies the length of the scaffold tower in bays. A tied tower is limited to one or two bays along the length of the elevation.
  • Maximum bay length: Specifies the maximum bay length permitted for the scaffold configuration.
  • Scaffold base level: Specifies the vertical distance between ground level and the base of the scaffold when the scaffold is supported on a building or other permanent structure.
  • Lift height: Specifies the maximum scaffold lift height.
  • Main boards: Specifies the maximum width of the main scaffold platform in boards.
  • Inside boards: Specifies the maximum number of inside boards.

Lift Boarding

  • Alternate lifts boarded: Specifies whether the scaffold is boarded at alternate lifts from the top lift downward.
  • Number of lifts: Specifies the total number of scaffold lifts, whether boarded or unboarded.
  • Number of boarded lifts: Specifies the maximum number of boarded lifts when alternate lift boarding is not selected.
  • Number of unboarded lifts: Specifies the maximum number of lifts that are not boarded.
  • Ladder landings: Specifies whether ladder landing platforms will be provided at unboarded lifts.

Cladding and Edge Protection

  • Cladding: Select unclad scaffolding, unclad scaffolding with plastic or wire brick guards, high-permeability debris netting, or sheeting/low-permeability debris netting.
  • Inner guard rails: Specifies whether internal edge protection is provided at boarded and unboarded lifts.
  • Top lift guard rails: Specifies the edge protection provided at the top lift.
  • Inner toe boards: Specifies whether inner toe boards are provided at boarded lifts.

Tube Material and Bracing

  • Tube material: Select Type 4 galvanised steel tubes to BS EN 39, cold formed galvanised steel tubes to BS EN 10219-1 grade S355, or hot formed galvanised steel tubes to BS EN 10210-1 grade S355.
  • Use structural transom units: Specifies whether TG20 compliant prefabricated structural transoms will be used at every node point.
  • Provide ledger bracing: Specifies whether ledger bracing will be provided. Where structural transom units are used with un-sheeted scaffolding, the compliance check determines whether ledger bracing may be omitted.

Double Standards and Foot Lift

  • Double standards: Specifies whether the scaffold standards are doubled to increase their load capacity. If Automatic is selected, the software determines whether double standards are required during the TG20 compliance check.
  • Foot lift: Specifies whether a foot lift is provided. Where Automatic is selected, the requirement for a foot lift is determined by the TG20 compliance check.
  • Double standards height: Specifies the height of the secondary standards. When automatic double standards are selected, the required height is calculated automatically.

Ties and Façade

  • Tie pattern: Select from the tie layouts defined for tied towers in TG20:21. Tie pattern A provides ties at alternate lifts, while tie pattern D provides ties at every lift in an alternating pattern.
  • Tie pattern A: Ties are provided at alternate lifts. Tie pattern A should be used to tie a scaffold with lift heights greater than 2.0 m at every lift.
  • Tie pattern D: Ties are provided at every lift in an alternating pattern.
  • Top lift tied: Specifies whether the top lift is tied at alternate standards. This can increase the maximum permitted height of a TG20:21 compliant tied tower depending on its configuration and wind exposure.
  • Top lift tying with pattern A: If this option is selected with tie pattern A, additional ties are provided at the top lift where they are not already provided by the tie pattern.
  • Clad scaffolds: Tied towers with debris netting or sheeting should be tied at the top lift at the ledger-braced frames to be TG20 compliant.
  • Façade permeability: Specifies whether the façade is impermeable, with no significant openings, or permeable, with significant openings.
  • Tie capacity is known: Specifies whether the capacity of the building fabric, anchor and tie assembly is known.
  • Tie capacity: Specifies the maximum permitted tie duty for the building fabric, anchor and tie assembly where this has been determined.
Add-ons

The Add-ons available for a tied tower are similar to those for an independent scaffold, except that bridge and inner cantilever platform options are not available.

Pavement Lift

  • Pavement lift: Specifies whether the scaffold includes a TG20:21 compliant pavement lift to provide a pedestrian thoroughfare.
  • Stabilisation: Select the method used to stabilise the pavement lift.
  • The pavement lift may be tied at alternate ledger-braced standards.
  • The pavement lift may be plan braced in every bay and tied at a lift no more than 2.0 m above the pavement lift.
  • The height of the second lift may be reduced so that it is no more than 4.0 m from the ground, with that lift tied at alternate standards.
  • If the scaffold consists only of a pavement lift, the pavement lift must be stabilised using ties. The other stabilisation options require at least two lifts.

Cantilever Fan

  • Cantilever fan: Specifies whether a TG20:21 compliant light-duty cantilever protection fan is included.
  • Cantilever fan lift: Specifies the lift at which the fan is located, counting upwards from ground level zero.

Not Available for Tied Towers

  • Bridge beam assemblies cannot be added because of the limited length of a tied tower.
  • Inner cantilever platforms are not presently permitted.
  • Rakers are not presently permitted.
Options Following a Compliance Check

If the tied tower fails the TG20 compliance check and SMART Compliance identifies changes that could allow it to pass, the available options depend on the tower configuration and the reason for the failed check.

Suggested Changes May Include:

  • Reduce the bay length.
  • Change the tie arrangement where required.
  • Tie the top lift at alternate standards.
  • Double the standards to a specified height.
  • Provide a foot lift.
  • Provide ledger bracing where required for scaffolding fitted with TG20 compliant prefabricated structural transom units.

Where suggested changes are available, the TG20:21 check section of the compliance report provides further information about the compliance criteria.

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