Skip to content
ScaFix
Norsk

Short answer

Independent vs putlog scaffold: what is the difference?

Both are classic UK tube-and-fitting scaffolds, and both are tied to the building. The difference is what carries the inside of the platform: a second row of standards, or the wall being built.

· How the numbers are computed ·

Kwikstage scaffolding around a house of 11.4 × 5.3 m with a gabled roof (eaves 4.5 m, ridge 6 m), drawn by the ScaFix 3D model
Kwikstage around the example house, as ScaFix draws it in 3D.

What is the difference between an independent and a putlog scaffold?

An independent scaffold stands on two rows of standards, inner and outer, joined by ledgers and transoms, so it carries its own load and is only tied to the building (Scaffmag). A putlog scaffold has one outer row; the inner ends of its putlogs rest in the brickwork as the wall rises, so it suits new masonry only.

Before you rely on this guide

This guide summarises published rules to help you plan and is not legal advice. It has not been reviewed by a qualified scaffold designer or engineer. ScaFix is a planning aid, not structural approval: the manufacturer's instructions, the scaffold design and a competent person's inspection decide what is built and used on site.

How do the two scaffolds compare?

The independent scaffold is the general choice for existing buildings, and the putlog scaffold a bricklayer's scaffold for new walls. Both still need ties and bracing, both follow TG20:21 or a design in the UK, and both can carry a platform four or five boards wide. The table sets out the differences.

Independent tied scaffoldPutlog scaffold
StandardsTwo rows, parallel to the buildingOne row, parallel to the building
Inside of the platformCarried by the inner standards and transomsPutlog blade bearing on the brickwork
Typical useExisting facades, refurbishment, painting, cladding workNew brick or block walls as they rise
Distance to the wallInner row as close as practicable; about 300 mm leaves room for one board insideStandards set out for a platform four or five boards wide
TiesTied at the recommended frequencyThe same number of ties as an independent scaffold; reveal ties not recommended
BracingLedger bracing on alternate pairs of standards, sway bracing at least every 30 mSway bracing at least every 30 m; no ledger bracing in the finished scaffold

The rows follow Scaffmag's tube-and-fitting guidance on independent tied and putlog scaffolds.

When is a putlog scaffold used?

On new masonry, while the wall is being built. The blade end of each putlog is laid flat on the brickwork with as much bearing as possible, so the bricklayer builds the wall around it. Over an opening there is nothing to bear on, so a bridle tube spanning the neighbouring putlogs carries the inner end instead.

That dependence on the wall is the putlog's main limit. It cannot go up against an existing facade without holes being cut into it, the brickwork must be strong enough to take the bearing, and the scaffold is only as stable as its ties allow. Reveal ties, which wedge a tube into a window opening, are not recommended on a putlog scaffold.

SGB CUPLOK scaffolding around a house of 11.4 × 5.3 m with a gabled roof (eaves 4.5 m, ridge 6 m), drawn by the ScaFix 3D model
SGB CUPLOK around the example house, as ScaFix draws it in 3D.

When is an independent scaffold the better choice?

Almost always on an existing building. Because both rows of standards stand on the ground, nothing bears on the facade, which is why render, stone, glazing and painted surfaces are scaffolded this way. It is also the type the system scaffolds share: modular and frame systems are all built with an inner and an outer row.

TG20:21 added tied independent scaffolds with up to three inside boards, so part of the platform can run between the inner standards and the wall when the work needs it close. A wider gap to the wall is a fall risk of its own, covered in how far a scaffold can be from the wall.

Does either one need a design?

Not if it is built within TG20:21 or the manufacturer's instructions, but sheeting or loading can push either one outside. HSE lists the scaffolds that normally need a bespoke design, among them cantilevered scaffolds and system scaffolds outside the maker's guidance, and NASC warns that cladding acts like a sail, raising the forces on the ties.

The rules are set out in when a scaffold needs a design in the UK, and the counts behind a tube-and-fitting job in the tube and fitting quantities guide.

How does ScaFix model them?

ScaFix plans independent scaffolds only. Every system in its catalogue, tube and fitting included, stands on an inner and an outer row of standards, and the parts list counts both rows, the transoms and the ties. A putlog scaffold, with its bearing in the brickwork, is outside what the engine models.

Planning information, not structural approval. In Great Britain a scaffold is built to TG20:21, the manufacturer's instructions or a bespoke design, and a competent person inspects it before use and at least every 7 days.

Frequently asked questions

Is a putlog scaffold safe on an old building?

Usually it is the wrong choice. The putlogs need bearing in the brickwork, so on an existing facade they mean cutting holes; an independent scaffold stands clear of the wall and is only tied to it.

Does a putlog scaffold need ties?

Yes. Scaffmag's guidance gives it the same number of ties as an independent tied scaffold and advises against reveal ties.

Why is it called an independent scaffold?

Because it carries its own weight and load on two rows of standards instead of bearing on the building. It is still tied to the building for stability.

How wide is a putlog scaffold?

Its standards are set out for a platform four or five boards wide, which with 225 mm boards is about 0.9 to 1.1 m of deck.

Sources

Primary sources used for this article, with the date each was read.

Try one week – €0.98See the demo house in 3DSee ScaFix

First week €0.98, then €9.98/week. Full Pro. Cancel anytime.