Scaffolds are rarely independent structures. Ties are generally fixed to the adjacent building / fabric / steelwork to provide stability for the structure.

General practice is to attach a tie every 4m on alternate lifts (traditional scaffolding). Prefabricated System scaffolds, however, require structural connections at all frames – ie. 2-3m centres.  The ties are coupled to the scaffold as close to the junction of standard and ledger (node point) as possible. Due to recent regulation changes, scaffolding ties must support +/- loads (tie/butt loads) and lateral (shear) loads.

Due to the different nature of structures there are a variety of different ties to cover all potential eventualities.

Through ties are put through structure openings such as doors and windows. A vertical inside tube crossing the opening is attached to the scaffold by a transom and a crossing horizontal tube on the outside called a bridle tube. The gaps between the tubes and the structure surfaces are packed or wedged with timber sections to ensure a solid fit.

Scaffold Anchor Tie

Box ties are used to attach the scaffold to suitable pillars or comparable features. Two additional transoms are put across from the lift on each side of the feature and are joined on both sides with shorter tubes called tie tubes. When a complete box tie is impossible a l-shaped lip tie can be used to hook the scaffold to the structure, to limit inward movement an additional transom, a butt transom, is place hard against the outside face of the structure.

Sometimes it is possible to use anchor ties (also called bolt ties), these are ties fitted into holes drilled in the structure. A common type is a ring bolt with an expanding wedge which is then tied to a node point.

Scaffolding Reveal Tie

The least ‘invasive’ tie is a scaffolding reveal tie which use an opening in the structure but use a tube wedged horizontally in the opening. The reveal tube is usually held in place by a reveal screw pin and protective packing at either end. A transom tie tube links the reveal tube to the scaffold. As reveal ties rely wholly on friction and require regular checking they are not well regarded so it is not recommended that more than half of all ties be reveal ties.

Raker

Rakers are used if it is not possible to use a safe number of scaffolding ties. These are single tubes attached to a ledger extending out from the scaffold at an angle of less than 75° and securely founded. A transom at the base then completes a triangle back to the base of the main scaffold.