U-ledger and deck transom

A transverse ledger with an upward-facing U-profile into which deck claws hook; it carries the working platform of a modular scaffold.

Also called: U-transom, deck bearer, deck ledger, U-profile ledger, deck transom

Every scaffold deck needs two bearings at its ends. That job falls to deck transoms. In a modular scaffold they run across the scaffold between inner and outer standard at every working level. If the transom is an open U-profile, it is called a U-ledger. The deck claws drop into the channel and are held positively.

A transom too weak for the chosen load bends and, at worst, lets the decks drop out.

Design and variants

A U-ledger is a pressed steel channel with a wedge head at each end. The opening faces upwards and the flanges are sized so the claws sit snugly. The whole part is galvanised.

• Lengths: matched to the scaffold width, such as 0.73 m for a painting and rendering scaffold with two decks or 1.09 m for bricklaying with three, plus wider sizes for work platforms.
• Reinforced U-ledgers: with an additional bottom chord or truss for longer spans and higher load classes.
• Deck transom as a general term: a round tubular ledger is also a deck transom when decks lie on it. What counts is that deck and profile match.
• On frame scaffolds: the top transom of the frame is often a U-profile itself; separate U-ledgers are mainly needed for intermediate levels or at the base.

Fitting

1. Stand the standards and link the bay with longitudinal ledgers.
2. Slide the U-ledger across the scaffold with its wedge head over the rosette and push the wedge through the small hole. The open side must face up.
3. Drive the wedge with the 500 g hammer until it no longer gives.
4. Lay the decks and close the bay without gaps.
5. Lock the decks against uplift. With U-profiles this usually takes a separate part, the deck lock, fitted over the deck ends between the standards.

Dismantling runs the other way: release the lock, lift out the decks, remove the ledger last.

What to check

• A missing anti-lift device is the most frequent defect on U-profiles. Wind or a knock from below can lever unsecured decks out.
• Flanges must not be bent open or dented, otherwise the claws no longer seat properly.
• Use the reinforced version for heavy loads or wide bays. Which ledger achieves which load class under EN 12811-1 is stated in the instructions; see also load classes and width classes.
• Do not combine U-ledgers with decks made for round tube, even if it seems to fit at first glance.
• When buying used, look into the channel. Concrete, render lumps and rust pockets there signal poor care and stop decks from seating cleanly.

U-profile or round tube?

The U-profile is regarded as very robust and is common in industrial scaffolding, but needs the extra part against uplift. With round tube the lock is usually built into the deck. What matters is that a firm decides on one variant or keeps its stock strictly separate – mixed stock costs time and nerves on site. Used U-ledgers are listed under ledgers.