The main types of scaffold used in construction

Independent tied scaffold

The most common scaffold in the UK. Two parallel rows of standards carry the working platforms — one row next to the building, one outboard — with the whole structure tied into the building for stability. It stands on its own legs rather than relying on the wall to carry load.

Independent scaffold is what you see on almost every re-roof, render, window replacement and facade repair. It suits any building that can take ties, and it is the default unless something about the site rules it out.

• Used for: roofing, rendering, brickwork, painting, window and fascia replacement
• Needs: reasonable ground bearing at the base and the ability to tie into the structure
• Watch for: conservatories, extensions and bay windows, which need bridging or beaming

Putlog (bricklayer's) scaffold

A single row of standards with the inner end of each transom built into the wall itself, resting in a joint left open by the bricklayer. It is a traditional new-build masonry scaffold and uses less material than an independent, but it depends on the wall being strong enough to carry it and is used far less than it once was.

• Used for: new masonry construction as the wall rises
• Needs: a wall able to carry the putlog ends, and holes made good afterwards
• Rarely appropriate for: refurbishment or any wall of unknown condition

Birdcage scaffold

A grid of standards and ledgers supporting one large working platform, usually built inside a building so trades can work across an entire ceiling, soffit or atrium at once. Rather than moving a tower around, everyone works from a single continuous deck.

Birdcages come into their own in churches, halls, warehouses, retail units, plant rooms and any space with a high ceiling that needs plastering, painting, mechanical or electrical work.

• Used for: ceilings, soffits, atria, internal M&E and decoration
• Needs: a floor able to carry the loads, and careful planning around anything staying in use below
• Advantage: a whole trade team works simultaneously instead of queuing for a tower

Suspended scaffold

A platform hung from above on wire ropes, cradles or needles from the roof structure, rather than built up from the ground. It is the answer when the ground beneath simply cannot be used — over water, over a live road, over an atrium, or on a tower block where a ground-up scaffold would be absurd.

• Used for: high-rise facade work, cleaning, glazing, repointing and inspection
• Needs: a designed suspension arrangement and a structure capable of carrying it
• Always: a designed scaffold with calculations, never a standard configuration

Cantilever and truss-out scaffold

Where the base of a building cannot be obstructed — a busy pavement, a shopfront that must stay open, a river frontage — the scaffold can be cantilevered out from the building on needles passed through openings, or supported on a beam spanning the obstruction.

This is one of the most common reasons a job needs a designed scaffold. The loads are concentrated into a small number of points, so the structure taking them has to be checked.

• Used for: high streets, shopfronts, restricted ground, over-water frontages
• Needs: design, calculations and often the agreement of a structural engineer

Temporary roofs, edge protection and staircase towers

Several scaffold types exist to protect people and the building rather than to provide working access.

• Temporary roofs — self-supporting pitched structures over a building so re-roofing and structural repair can continue in any weather.
• Edge protection — guardrails and barriers to open edges, slabs, leading edges and roof perimeters, protecting people rather than giving access.
• Staircase towers — proper stair access into a scaffold or a building under construction, replacing ladders for large teams and materials.
• Loading bays, hoists and rubbish chutes — material handling built into the scaffold rather than bolted on afterwards.
• Pedestrian walkways and fans — protecting the public where the scaffold meets a footpath.

Shoring and back-propping

Shoring is structural, not access. Props, needles and frames take load from a building temporarily while something beneath it is removed, opened up or rebuilt — a steel going in, a wall coming out, a basement being dug, a floor being replaced.

Back-propping does the same job in reverse on new build, spreading load from a freshly poured slab down through the floors below until the concrete has gained strength.

Both are temporary works in the formal sense: they are designed, they carry calculated loads, and they are installed and removed in a specific sequence agreed in advance.

If anyone offers to prop a structural opening without a design, stop. This is the category of scaffolding where getting it wrong damages the building rather than just delaying the programme.

Which type does your job need?

You do not have to know the answer before you call — but this is roughly how the decision goes.