Vertical frame
The welded frame of two uprights and a top transom that carries every lift of a frame scaffold and sets platform width and lift height.
Also called: scaffold frame, facade frame, standing frame, steel frame, aluminium frame
On a frame scaffold most of what you see from the street are vertical frames. They stand at right angles to the wall, one at each end of every bay, and form the skeleton. Each frame takes the load from decks, materials and people straight down into the base jacks and the ground. It also fixes two dimensions: the width of the working platform and the height from one lift to the next.
How a frame is made
Two uprights of 48.3 mm (1.9 in) tube are joined at the top by a transom. On most systems that transom is a profile into which the claws of the decks hook. A short intermediate member or a corner gusset keeps the frame square. A spigot is pressed into the top of each upright so the next frame simply slides over it. The outer upright carries the fittings for guard rails, toe boards and the vertical diagonal – drop-lock pins, bolts or wedge pockets, depending on the system. Some frames also have fittings on the inner upright, which allows an inside guard rail where the gap to the wall becomes too wide.
Sizes and variants
- Height: 2.00 m (about 6 ft 7 in) is standard and gives the usual lift height.
- Width: narrow frames of 0.70 or 0.73 m take two decks side by side and suit painters and renderers. Bricklaying scaffolds are 1.00 or 1.09 m deep with three decks, so blocks and mortar tubs fit next to the workplace. The exact figure depends on the manufacturer.
- Material: galvanised steel as the robust standard; aluminium is lighter to pass up but dents more easily.
- Special frames: compensation frames for level differences, passage frames for pedestrians, eaves and parapet frames, and reducers from wide to narrow.
What to check on used frames
Sight along both uprights. A slight bow – typically left by a forklift or a lorry – reduces the load capacity considerably, and such a frame belongs on the scrap pile. The spigot must neither wobble nor turn. Pins and bolts should move freely; seized fittings tempt crews to lay guard rails on loosely. Look for cracked welds at uprights and transom and for a deck profile that has been bent open. The embossed mark with manufacturer and year shows which system you are buying. White rust on the zinc is mostly cosmetic, deep rust at the foot of an upright or at a weld is not.
Typical mistakes
- Mixing frames of different systems in one scaffold. What may be combined is stated only in the system's instructions for assembly and use.
- Leaving out the diagonal in the first bay, so the starting frames stand unbraced.
- Fixing ties far away from the node instead of on the upright close to the transom.
Used frames in complete packages are listed under frame scaffolding. Contractors moving to modular material can trade frames in through the scaffolding exchange, where one frame counts against one standard.