Posts Tagged ‘Scaffolding Hire’

Scaffolding Regulations

Wednesday, September 23rd, 2009

Scaffold regulations apply to any work done at a height. There are various basic regulations that are to be adhered to and implemented for all types of scaffold towers and there are more specific ones which are relevant to only certain types of scaffolds such as mobile towers for example.

 

Mobile Scaffold Towers regulations

Regulations that apply to mobile scaffold towers specifically include common sense points like, for example, that all wheels must be locked and secured before workers are allowed to safely step onto the scaffold tower. This is to prevent the structure from moving. Also, obviously, all workers must descend from the structure before it is moved, this is to prevent injuries. While actually moving the scaffold tower an eye must be kept out for any wires, electric cables (or anything else of the sort) installed above the scaffold, as these could get in its way and cause complications.

 

Work at Height Regulations 2005

In the UK a complete set of regulations can be found in the “Requirements for All Working Platforms” section of “The Work at Height Regulations 2005”.. Possibly the most important regulation may be that every scaffold must be capable of holding at least four times the maximum intended amount and mass of people.
The Work at Height Regulations 2005 consolidated previous UK and European legislation on work at heights. The Regulations apply to any work at a height where there is a risk of a fall liable to cause injury. This includes work below ground level and at a low height. The Regulations place duties on employers, the self-employed, and any person that controls the work of others.

 

As part of the Regulations, duty holders must ensure:

  • work is planned and organised.
  • competent personnel
  • risks are assessed and appropriate work equipment used.
  • risks from fragile surfaces are properly controlled.
  • equipment is properly inspected and maintained.

 

The HSE has determined a simple hierarchy for managing and selecting equipment for work at height. In this, duty holders must:

  • avoid work at height where they can.
  • use work equipment or other measures to prevent falls where they cannot avoid working at height.
  • where they cannot eliminate the risk of a fall, use work equipment or other measures to minimise the distance and consequences of a fall should one occur.

 

According to the HSE, common factors resulting in falls from height include:

  • Failure to provide safe systems of work.
  • Failure to ensure that safe systems of work are followed.
  • Inadequate information, instruction, training or supervision provided.
  • Failure to use appropriate equipment.
  • Failure to provide safe plant/equipment.

 

The HSE’s key messages on preventing falls from height are:

  • Follow good practice for work at height.
  • Follow your risk assessment, plan and organise your work properly and make sure everyone involved is competent to their level or responsibility.
  • Try to avoid the need for work at height where you can. Where you can’t, take steps to prevent falls, where you cannot prevent a fall then you must mitigate the risk of injury should a fall occur.
  • Always select collective measures to prevent falls (such as guardrails and working platforms) before other measures which may only mitigate the distance and consequences of a fall or which may only provide personal protection from a fall.

 

For full details please visit:

http://www.opsi.gov.uk/si/si2005/20050735

and

http://www.opsi.gov.uk/si/si2007/uksi_20070114_en_1

 

 

European regulations

This European Standard specifies performance requirements and methods of structural and general design for access and working scaffolds. Requirements given are for scaffold structures that rely on the adjacent structures for stability. In general these requirements also apply to other types of working scaffolds.

 

The purpose of a working scaffold is to provide a safe place of work with safe access suitable for the work being done.

The European Standard includes rules for structural design, which are of particular relevance to scaffolds made of certain materials. It is to be used in conjunction with the Eurocodes for structural design.

 

Design and inspection issues

• Scaffold should be designed by calculation, by a competent person, to ensure it will have adequate strength and stability. Unless a scaffold is a basic configuration described in recognised guidance e.g. NASC Technical Guidance TG20 for tube and fitting scaffolds or manufacturers’ guidance for system scaffolds.
• All scaffolding should be erected, dismantled and altered in accordance with the manufacturers’ erection guide for system scaffolds or NASC guidance document SG4 for tube and fitting scaffolds.
• For scaffolds that fall outside the scope of ‘Basic Scaffolds’ as described in bullet point 1, the design information should describe the sequence and methods to be adopted when erecting, dismantling and altering the scaffold, if this is not covered by published guidance as detailed in bullet point 2.
• Any proposed modifications or alterations outside a generally recognised standard configuration should be designed by a competent person.
• Handover certificates should refer to relevant drawings, permitted working platform loadings and any specific restrictions on use.
• All scaffolding inspection should be carried out by a person whose training and competence reflects the type and complexity of the scaffold they are inspecting.  Examples of competency include the Construction Industry Scaffolders Registration Scheme (CISRS) or an industry experienced individual who has received training under a recognised manufacturer/supplier scheme e.g. Safe Access-Fall Elimination (SA-FE) for the specific configuration he is inspecting.
• A non-scaffolder who has attended a suitable scaffold inspection course and has the necessary background experience would be considered competent to inspect a basic scaffold (ie a site manager).
• The scaffold inspection report should note any defects and corrective actions taken, even when those actions are taken promptly as this assists with the identification of any recurring problems.
• To prevent use by unauthorised persons of incomplete scaffolds, relevant warning signs identifying the areas where access is not permitted should be displayed at the access points to these areas.  In addition, access to the incomplete areas should be prevented by suitable physical means.

 

Competence and supervision issues

• All employees should be competent (or in the case of trainees, supervised by a competent person) for the type of scaffolding work they are undertaking and should have received appropriate training relevant to the type and form of scaffolding they are working on.
• Employers must provide appropriate levels of supervision taking into account the complexity of the work and the levels of training and competence of the scaffolders involved. 
• As a minimum requirement, every scaffold gang should contain an appropriately qualified scaffolder for the type and complexity of the scaffold to be erected, altered or dismantled.  This may be an individual who has received training under an industry recognised training scheme, e.g. CISRS, and has been awarded the scaffolder card or someone who has received training under a recognised manufacturer/supplier scheme, e.g. SA-FE, to the limit of the configuration(s) involved.   
• Trainee scaffolders should always work under the direct supervision of a qualified scaffolder (i.e. a working foreman).  Scaffolders are classed as ‘trainees’ until they have completed the approved training and assessment required to be deemed qualified.
• Erection, alteration and dismantling of complex designed scaffolding (e.g. suspended scaffolds, shoring, temporary roofs etc) should be done under the direct supervision of a competent person.  This may be a qualified Advanced scaffolder, a design engineer providing they possess the necessary industry experience or alternatively an individual who has received training under a recognised manufacturer/supplier scheme to the limit of the configuration(s) involved.

 

Scaffold structures that need to be designed

1. Dead Shores
2. Flying shores
3. Raking shores
4. Cantilevered scaffolds
5. Truss-out Scaffolds
6. Access Birdcages
7. Façade retention
8. Access scaffolds with more than the 2 working lifts allowed with TG20 ‘Basic Scaffolds’
9. Buttressed free-standing scaffolds
10. Temporary roofs and temporary buildings
11. Support scaffolds
12. Loading Bays founded on the ground
13. Mobile and static towers outside base/height limitations
14. Free standing scaffolds outside base/height Limitations
15. Temporary ramps and elevated roadways
16. Staircases and fire escapes
17. Spectator Terraces and Seating Stands         
18. Bridge scaffolds
19. Towers requiring guys or ground anchors
20. Offshore scaffolds outside Offshore Contractors Association (OCA) handbook
21. Pedestrian footbridges or walkways
22. Slung and Suspended scaffolds
23. Protection fans, Nets and Pavement Frames
24. Marine scaffolds
25. Boiler scaffolds
26. Power line crossings
27. Lifting gantries and towers
28. Steeple scaffolds
29. System scaffolds outside users guide parameters
30. Sign board supports
31. Sealing end structures
32. Temporary Storage on Site
33. Masts, Lighting Towers and Transmission Towers
34. Advertising hoardings/banners
35. Any scaffold structure subject to:
• Vibration
• High Loading
• Long term duration
• High risk areas
• Loading from passenger/goods hoists

 

Note: The above list is not exhaustive and any scaffold that does not comply with manufacturers guidelines as published in handbooks will require a specific design produced by a competent person.

System Scaffold

Wednesday, September 23rd, 2009

The two main types of scaffolding systems sold and used in the UK are Kwikstage and Scaf-lok (similar system to “Cuplok”, designed by S.G.B., one of the world’s leading suppliers of access and formwork products).

 

Cuplok, or Scaf-lok, is a galvanised system that uses a “cup” and “blade” type to lock the various ledgers and standards together.

 

Kwikstage is the most commonly used system. The main difference to a Scaf-lok is that it comes painted in yellow and uses a “wedge” and “V-pressing” to locate and lock all components together.

Conventional Scaffold

Wednesday, September 23rd, 2009

 

 

The main types are:

  1. Independent scaffold
  2. Single pole or putlog scaffold
  3. Suspended (swingstage) scaffold
  4. Special scaffold

 

 

 

1. Independent scaffold

Independent Scaffolding

Independent Scaffolding

Independent scaffolds are ‘free standing’ but follow the same principal as putlog scaffolds. Putlogs are replaced with 5ft tubes and a row of standards and ledgers are erected on the inside as well as the outside to provide support, in addition diagonal braces are fitted between standards to give stability. The inside standards should be placed close to the building if the scaffold is for access to a work level.

 

The scaffold should be tied into the building at approx every other lift and every 20ft if at all possible, double couplers should be used for connecting ties, if no suitable reveals etc are available then Hilti Rings can be used.

Types of Independent Scaffold are:

 

Birdcage scaffold

A birdcage scaffold is an independent scaffold that consists of more than two rows of standards in both directions and is connected by ledgers and transoms. It is mainly used for work that is to be carried out on a single level, such as ceilings.

 

Tower scaffold

A tower scaffold is an independent scaffold consisting of four vertical members connected longitudinally and transversely

 

Mobile Scaffold

A mobile scaffold is an independent scaffold that is freestanding and mounted on castors

 

Hung scaffold

A hung scaffold is an independent scaffold that hangs from another structure, but is not capable of being raised or lowered when in use.

 

 

 

2. Single pole scaffold (Putlog Scaffold)

Putlog Scaffolding

Putlog Scaffolding

A single pole scaffold consists of a single row of standards connected by ledgers. Putlogs are fixed to the ledgers and built into the wall of the building or structure making it completely dependant upon the structure against which it is placed for support.

 

As well as putlog couplers there are also putlog tubes. These have a flattened end or have been fitted with a blade. This feature allows the end of the tube to be within or rest upon the brickwork of the structure. They can be called a bricklayer’s scaffold and as such consist only of a single row of standards with a single ledger, the putlogs are transoms – attached to the ledger at one end but integrated into the bricks at the other. Spacing is as general purpose scaffold and ties are still required

A slot is left between two bricks and the putlogs are located in this. The bricklayer will have left putlog holes every 4 – 5 ft, there should also be double holes left to allow for board joints say every 13 ft. Once the scaffold is dismantled the holes should be made good with mortar.

The advantage of a Putlog Scaffold is that less materials are used as there are no inside standards or ledgers. The disadvantage is that if the ground dries out and shrinks slightly, or a heavy load is placed on the scaffold then as the standards and ledgers drop they lever the brickwork apart!

 

 

 

3. Suspended (swingstage) scaffold

A suspended scaffold incorporates a suspended platform that is capable of being raised or lowered when in use. An example of a suspended scaffold is a swingstage scaffold. These types of scaffolds are commonly associated with the types window washers

 

 

 

4. Special scaffolds

Cantilever scaffold

 

A cantilever scaffold is a scaffold that is supported by cantilevered load-bearing members.

 

Hanging bracket scaffold

 

Other hanging bracket scaffold systems may include horizontal members that are supported by floors of buildings or other structures. An engineer should design the hanging bracket scaffold and its means of support. A safe means of access and exit should be provided for persons installing a hanging bracket scaffold.

 

Spur scaffold

 

A spur scaffold is a scaffold that is supported by inclined load-bearing 

members.

 

Scaffolding Glossary

Wednesday, September 23rd, 2009

Scaffolding Glossary of Terms

 

A

ACCESS PLATFORM: A platform that gives access to and from places of work to persons, materials and equipment.

 

ACCESSORY: A fitting that is able to be attached to a structural member of a scaffold, or to join a structural member to something else.

 

ADVANCED SCAFFOLDER – a person who performs:

(a) the work of an intermediate scaffolder; and

(b) scaffolding work associated with:

 

i. hung scaffolds, including scaffolds hanging from tubes, wire ropes and

chains; or

ii. suspended scaffolds.

 

 

B

BARROW HOIST: Modular transportable lifting device used to handle light loads.

 

BAY LENGTH: The horizontal distance between any two longitudinally-adjacent standards in an independent scaffold or a single-pole scaffold, or the horizontal distance between any two longitudinally-adjacent support points on the cradle of a suspended scaffold.

 

BACK SPLICE: A splice in the end of a fibre rope to prevent it from unlaying.

 

BALD EYE: An eye in a rope which is not protected by a thimble. It is also called a ’soft eye’.

 

BATTEN: These wood boards are placed between the horizontal poles or transoms of the scaffolding to create a working platform.

 

BASIC SCAFFOLDER – a person who performs scaffolding work associated with:

(a) prefabricated scaffolds;

(b) cantilevered materials hoists with a maximum working load of 500 kg;

(c) ropes;

(d) gin wheels;

(e) safety nets and static lines; or

(f) bracket scaffolds.

 

BASEPLATE – a metal plate that is able to distribute the load from a standard to

a supporting structure and is an integral part of scaffolding.

 

BIRDCAGE SCAFFOLD: An independent scaffold consisting of more than two rows of standards connected by ledgers and transoms.

 

BLOCK AND TACKLE: A sheave block or blocks used with fibre rope.

 

BOATSWAIN’S CHAIR: A suspended scaffold where the platform is a chair or similar device, suitable for use by one person.

 

BODY BELT: A safety belt designed to be worn around the waist and which does not have shoulder straps or leg straps.

 

BOOM-TYPE ELEVATING WORK PLATFORM: A powered – telescoping device, hinged device or articulated device or any combination of these used to support a platform on which personnel, equipment and materials may be elevated to perform work. Also known as “cherry pickers”.

 

BRACKET SCAFFOLD: A scaffold that has a platform carried on frames attached to or supported by a permanent or temporary construction.

 

BRICKGUARD: A meshed panel secured between a guardrail and toeboard, and sometimes incorporating a kickplate.

 

BRICKLAYER’S SCAFFOLD: A single-pole scaffold.

 

BUSH ROLLER CHAIN: Chain constructed with parallel flat links and cylindrical rollers, such as bicycle and motorcycle drive chains.

 

 

BUTT – a tube fixed to a scaffold and butting to an adjacent structure, to

prevent horizontal movement of the scaffold in the direction of the structure.

 

BUTTRESS – a support to the side of a scaffold which provides for an effective

increase in the on-ground base width, allowing a greater freestanding height.

 

 

C

CANTILEVER: A beam, structural member or similar which is anchored at one end and which is free at the other end.

 

CANTILEVER BUILDERS’ HOIST: A builders’ hoist where the car, bucket or platform is cantilevered from, and travels up and down externally to a face of, the support structure.

 

CANTILEVER PLATFORM MATERIALS HOIST: A powered builder’s hoist which has the lift platform cantilevered from the hoist tower. It moves materials only, up and down the face of a building or structure. Also called a ‘barrow hoist’.

 

CANTILEVER SCAFFOLD: A scaffold that is supported by cantilevered load-bearing members.

 

CANTILEVERED CRANE LOADING PLATFORM: A temporary loading bay cantilevered from the face of a building or structure to land or lift crane handled loads.

 

CAR: Load carrying carriage on a materials and personnel hoist.

 

CASTOR: A swivelling wheel attached to a scaffold, to contain falling debris.

 

CATCH PLATFORM – a platform attached to the lower end of a scaffold, to contain falling objects.

 

CHERRY PICKER: Boom type elevating work platform.

 

CLIMBING FRAME: An internal or external frame used to lift the crane from the tower sections of a tower crane for climbing up or down.

 

COMPETENT PERSON: A person suitably qualified, adequately trained and appropriately experienced for the particular class or kind of work described.

 

COUNTERWEIGHT: A weight or series of weights that counterbalance a scaffold against overturning.

 

COUPLER: right angle and putlog couplers connect the main horizontal poles (ledgers and transoms) of the scaffolding to the vertical poles (the standards or uprights).

 

CRADLE – the suspended platform part of a suspended scaffold.

 

CROSS BRACES: fitted to the main vertical scaffolding poles, these play an important part in making the structure more stable.

 

 

D

DEBRIS NET: A fine mesh net usually laid over an industrial safety net in order to catch small light items of falling debris.

 

DERRICK CRANE: A slewing strut-boom crane with the boom pivoted at the base of a mast which is either guyed (guy derrick) or held by backstays (stiff-leg derrick). Can luff under load.

 

DOUBLE ROPE SUSPENDED SCAFFOLD: A scaffold where the cradle is suspended using two hoists and two suspension ropes at each support point.

 

DRAGLINE: A crane fitted with a bucket or scoop which is thrown outwards and retrieved by a drag cable arrangement.

 

DROP SCAFFOLD: A hung scaffold.

 

DUAL COVERAGE: Work which can be performed by someone who holds either the appropriate class of rigging certificate or the appropriate class of scaffolding certificate, because the work is within the scope of both types of certificate.

 

 

E

EOHTC: Electric overhead travelling crane – an electric powered bridge or gantry crane.

 

EWP: Elevating work platform.

 

ELEVATING WORK PLATFORM: A telescoping device, scissor device or articulating device used to support a working platform.

 

EXTENSION LADDER: A non self supporting portable ladder that is adjustable in length and consists of two or more sections with guides or brackets to permit length adjustment.

 

 

F

FABRICATED HUNG SCAFFOLD: A pre-assembled scaffold hung from another structure but which is not capable of being raised or lowered when in use. It is sometimes used for large steel erection projects.

 

FINIAL COUPLER: A coupler that joins two scaffold tubes in the same plane.

 

FITTING BINS: often designed to stack together, these are used to hold the various parts required to build the scaffolding 

 

FIXED CRADLE: A cradle that does not traverse horizontally, but is capable of being raised and lowered.

 

FRAME SCAFFOLD: A scaffold assembled from prefabricated frames, braces and accessories.

 

FRAME TRESTLE SCAFFOLD: A scaffold, other than a trestle ladder, consisting of self supporting stands that support scaffold planks.

 

FREESTANDING SCAFFOLD: A scaffold that is not attached to any other structure and is stable against overturning, on its own account or if necessary assisted by stabilisers, outriggers, counterweights or backup bays.

 

FRICTION CLAMPS: used to erect scaffolding onto or around tubular structures, such as pipes. They are secured using a high-tension chain.

 

.

 

G

GANTRY: A structure, constructed from structural steel, scaffolding or structural timber, that is primarily intended to support a protection deck or portable buildings such as amenity sheds.

 

GANTRY CRANE: A powered crane with one or more bridge beams. The beams are supported at each end by legs mounted on travelling end carriages. They have a crab with one or more hoisting units that are able to travel across the bridge beam or beams. Used where there is no supporting building for the crane.

 

GUARDRAIL – a horizontal structural member to prevent persons from falling off

any platform, walkway, stairway or landing.

 

GUY ROPE – a rope used to help stabilise a vertical member

 

H

HAMMERHEAD CRANE: A tower crane with a counterweighted horizontal boom which supports a traversing crab for hoisting.

 

HAZARD: An object or situation likely to cause an incident leading to injury or death.

 

HEAD BLOCK: The top block in a purchase, tackle or block at the head of a crane boom or hoist.

 

HEADACHE BALL: A spherical overhauling weight.

 

 

HEAVY DUTY WORKING PLATFORM: A scaffold platform with a duty live load capacity of 675 kg per bay. This is three times the capacity of a light duty platform.

 

HEIGHT OF A SCAFFOLD: The vertical distance from the supporting structure to the highest working platform of the scaffold.

 

HOIST: An appliance used to raise or lower a load with no horizontal movement.

 

HOISTS: Machines designed to lift materials and personnel.

 

HOISTING: Raising or lowering a load.

 

HOOK BLOCK: The lower block on a crane which incorporates a hook for slinging loads.

 

HUNG SCAFFOLD: An independent scaffold that is hung from another structure but is not capable of being raised or lowered when is use.

 

HYDRAULIC BOOM CRANE: A crane which has a boom which luffs using hydraulic power and usually also telescopes using hydraulic power.

 

 

I

INDEPENDENT SCAFFOLD: A scaffold consisting of two or more tows of standards connected together longitudinally and transversely.

 

INDIVIDUAL CRADLE: A cradle of one bay length.

 

INTERNAL PERIMETER SCAFFOLD: A scaffold erected alongside the inside perimeter of a penetration or shaft in a building or other structure.

 

INTERMEDIATE SCAFFOLDER – a person who performs:

(a) the work of a basic scaffolder; and

(b) scaffolding work associated with:

 

i. cantilevered crane loading platforms;

ii. cantilevered and spurred scaffolds;

iii. barrow ramps and sloping platforms;

iv. perimeter safety screens and shutters;

v. mast climbers; or

vi. tube and coupler scaffolds, including tube and coupler covered ways

and gantries.

 

K

Kwikstage (kwikform)): one of the two most commonly used scaffolding systems in the UK. The other is Scaf-lok, which is more expensive, mainly because it’s galvanised and doesn’t rust.

 

L

LADDER BRACKET SCAFFOLD: A bracket scaffold consisting of two or more single ladders or extension ladders that support planks by means of brackets, to provide a working platform.

 

LEDGERS: a key element of the scaffolding structure, these horizontal tubes fit between the main vertical poles.

 

LIFE / LIFT HEIGHT – the vertical distance from the supporting surface to the lowest ledge of a scaffold or level at which a platform can be constructed. Also, the vertical

distance between adjacent ledgers or levels of a scaffold at which a platform can be constructed.

 

LIGHT DUTY WORKING PLATFORM: A platform on a scaffold with a duty live load capacity of 225 kg per bay.

 

LOADING BAY: A platform on a scaffold for the storage of materials and equipment.

 

LOCOMOTIVE CRANE: A crane designed and intended for use on railway tracks.

 

LOWER BLOCK: The bottom block in a tackle or purchase from which the load is suspended.

 

 

 

M

MSDS: Material safety data sheet.

 

MAST CLIMBING WORK PLATFORM: A work platform used for temporary purposes to raise personnel and materials to a working position by means such as a rack and pinion drive mounted on an extendible mast, which may be tied to a building.

 

MATERIALS HOIST: A builder’s hoist used for raising and lowering materials (not personnel) including a cantilevered platform materials hoist.

 

MATERIAL SAFETY DATA SHEET: Manufacturer’s or supplier’s information about a substance, including any hazards associated with its transportation, storage and use.

 

MEDIUM DUTY WORKING PLATFORM: A platform on a scaffold with a duty live load capacity of 450 kg per bay. This is twice the capacity of a light duty platform.

 

MEMBER – anything that forms part of the scaffold assembly.

 

MOBILE CRANE: A crane which can travel over a supporting surface without the need for fixed runways or railway tracks and which relies on gravity for stability.

 

MOBILE SCAFFOLD: An independent free standing scaffold mounted on castors.

 

MODULAR SCAFFOLD: A scaffold assembled from prefabricated individual components, braces and accessories.

 

N

Needle – a cantilevered structural member that forms part of the scaffold

assembly.

 

O

OH&S: Occupational health and safety.

 

Outrigger: The structural member of a supported scaffold used to increase the base width of a scaffold in order to provide support for and increased stability of the scaffold.

 

 

P

PARAPETS – a vertical element usually located at the edge of a balcony, roof,

bridge or similar structure.

 

PERIMETER SCAFFOLD: A scaffold erected alongside the external face of a building or other structure.

 

PREFABRICATED PLATFORM: A framed assembly of one bay length, incorporating a walking surface, that is capable of connecting to its support structure in such a way as not be inadvertently dislodged. (One or more prefabricated platform units can be used side by side and end to end to form a working platform.)

 

PREFABRICATED SCAFFOLD: A scaffold assembled from prefabricated components and manufactured so that the geometry of the scaffolding is predetermined.

 

PUTLOG SCAFFOLD: A single pole scaffold.

 

PUTLOG TRESTLE SCAFFOLD: A scaffold consisting of scaffold planks that are supported at one end by non self supporting stands and at the other end by a wall.

 

 

R

RETURN: A part of a scaffold set up around the corner of a building or structure.

 

RIGGING: The use of mechanical loadshifting equipment and associated gear to move, place or secure a load including plant, equipment or members of a building or structure and to ensure the stability of those members, and for the setting up and dismantling of cranes and hoists, other than the setting up of a crane or hoist which only requires the positioning of integral outriggers or stabilisers.

 

ROUGH TERRAIN CRANE: A mobile crane designed to operate on unimproved natural terrain and disturbed terrain of construction sites.

 

S

SAFE WORKING LOAD: The maximum load which may be applied to a crane, hoist, rope, chain or sling for particular conditions of use.

 

SCAFFOLD: A temporary structure for supporting access platforms or working platforms. (See also the definitions for birdcage scaffold, boatswain’s chair, cantilever scaffold, freestanding scaffold, hung scaffold, independent scaffold, mobile scaffold, putlog scaffold, single-pole scaffold, spur scaffold, suspended scaffold and tower scaffold.)

 

SCAFFOLDER: A person engaged in erecting, altering or dismantling scaffolding.

 

SCAFFOLDING EQUIPMENT: Any component, assembly or machine used or intended to be used for the construction of scaffolding.

 

SHUTTER BRACKET SCAFFOLD: A bracket scaffold where the brackets are attached to formwork shutters.

 

SINGLE POLE SCAFFOLD: A scaffold consisting of a single row of standards that are connected together by ledgers and putlogs fixed to ledgers and built into the wall of a building or structure.

 

SINGLE ROPE SUSPENSION SYSTEM: A method of suspending a cradle using one hoist and a single suspension rope at each support point.

 

SLEWING CRANE: A crane with a boom or jib which has slewing capability.

 

SLEWING MOBILE CRANE: A powered mobile slewing crane. It does not refer to a front end loader, backhoe, excavator or similar equipment when configured for crane operation.

 

SLUNG SCAFFOLD: A hung scaffold.

 

SOLEBOARD – a board that is able to distribute the load from a load-bearing member to a supporting surface and is intended for use underneath baseplates.

 

SPECIAL DUTY WORKING PLATFORM: A platform on a scaffold designed for live loads greater than 675 kg per bay.

 

SPUR SCAFFOLD: A scaffold that is partially supported by inclined load bearing members.

 

STANDARD – a vertical structural member that transmits a load to a supporting

structure. They rest on square base plates, which help to spread the load.

 

STRUT – a member that supports a comprehensive force.

 

STUD BRACKET SCAFFOLD: A bracket scaffold of which the brackets are attached to studs of a timber frame building or other structure.

 

SUSPENDED SCAFFOLD: A scaffold incorporating a suspended platform which can be raised and lowered in normal use, including a boatswain’s chair.

 

 

SUSPENSION RIG: The portion of a suspended scaffold (including a trolley track) which is mounted at a higher level than the cradle and which supports and positions the cradle. Sometimes called a ‘roof rig’.

 

SUSPENSION MOUNTED HOIST: A scaffolding hoist that is mounted on a suspension rig or trolley track, with one end of the rope attached to the cradle.

 

SWING STAGE: A suspended scaffold with a single row of suspension ropes

 

 

 

T

TANK BRACKET SCAFFOLD: A bracket scaffold of which the brackets are able to be attached to the face of a metal tank, duct, boiler, structural beam or similar.

 

TIE – a member or assembly of members used to tie a scaffold to a

supporting structure. Every inside vertical pole must be tied at intervals to help it carry the weight of the scaffolding structure. There are a number of different ways of doing this, including the reveal or friction tie, ring tie, anchor tie, box tie and lip tie.

 

TRANSOM – a horizontal structural member transversely spanning an

independent scaffold between standards. A key element of the scaffolding’s structure, these rest on the main horizontal tubes or ledgers and support the boards of the platforms.

 

TOE BOARDS: for safety purposes, these planks are slotted into brackets around each platform. They also prevent items rolling off the edge.

 

TOWER CRANE: A boom or jib crane mounted on a tower structure.

 

TOWER FRAME SCAFFOLD: A prefabricated scaffold consisting of fabricated units and only able to be erected in the form of a tower.

 

TOWER SCAFFOLD: A scaffold of one bay.

 

TRACK MOUNTED CRANE: A mobile crane mounted on a crawler track base. It is not usually fitted with outriggers.

 

TRAVELLING CRADLE: A cradle capable of being moved horizontally.

 

TRAVERSING CRADLE: A travelling cradle.

 

TRESTLE LADDER SCAFFOLD: A scaffold consisting of trestle ladders supporting scaffold planks.

 

TRESTLE SCAFFOLD: A scaffold consisting of trestles and planks.

 

TUBE AND COUPLER SCAFFOLDING: A scaffold of which the standards, ledgers, braces and ties are circular tubes that are joined together by means of purpose designed couplers.

 

TUBECLAMPS: with names such as Short Tee, 3 Way Through Corner and 90 Degree Elbow, these are an essential part of the scaffolding structure. The scaffold poles or tubes simply slot into them, no nuts and bolts required.

 

TUBES: the term used for the steel or aluminium scaffolding poles.

 

V

‘V’ PRESSING: a connection point that secures the vertical poles to the horizontal.

 

VEHICLE LOADING CRANE: A powered slewing crane mounted on a vehicle for the principal purpose of loading and unloading the vehicle.

 

 

W

WINCH: An appliance which provides a means of hoisting or hauling a load.

 

WORK CAGE: A suspended scaffold cradle supported by a single suspension rope. Usually designed for one person.

 

WORKING LOAD LIMIT – the maximum working load that may be applied to any

component or system.

 

WORKING PLATFORM: A platform that is intended to support persons, materials and equipment.

 

Scaffolding Couplers

Wednesday, September 23rd, 2009

 

Scaffolding Couplers

Scaffolding Couplers

 

Scaffolding Couplers are the fittings which hold the tubes together. There are three basic types: scaffolding right-angle couplers, scaffolding putlog couplers and scaffolding swivel couplers. To join tubes end-to-end scaffolding joint pins (also called spigots) or sleeve couplers are used, or both together. Only right angle couplers and swivel couplers can be used to fix tube in a ‘load bearing connection’. Single couplers are not load bearing couplers and have no design capacity.

Other common materials include base plates, ladders, ropes, anchor ties, reveal ties, gin wheels, sheeting, etc.

 Despite the metric measurements given many scaffolders measure tubes and boards in imperial units. With tubes from 21 feet down and boards from 13 ft down.

 

Scaffolding Foundations

Wednesday, September 23rd, 2009

Often scaffold frameworks will require more than simple base plates to safely carry and spread the load and only on concrete or similar hard surfaces could one do without. Base plates are necessary for surfaces like pavements or tarmac. For heavier duty scaffold much more substantial baulks set in concrete can be required. For softer or more doubtful surfaces sole boards must be used, beneath a single standard a sole board should be at least 1,000 cm² with no dimension less than 220 mm.

 

A working platform requires certain other elements to be safe. They must be close-boarded, have double guard rails and toe and stop boards. Safe and secure access must also be provided.

Scaffolding Ties

Tuesday, September 22nd, 2009

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

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

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

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.

How Scaffolding works

Tuesday, September 22nd, 2009

The main elements of a scaffold are poles called scaffolding standards, scaffolding ledgers and scaffolding transoms.

 

Scaffolding Standards

Scaffolding Standards

 

Scaffolding Standards, also called uprights, are the vertical tubes that transfer the entire mass of the structure to the ground where they rest on a square scaffolding base plate to spread the load. At the centre of the base plate is a shank to hold the tube which is sometimes pinned to a scaffolding sole board to help distribute the weight.

 

Ledgers are horizontal tubes which connect between the standards stabilising the structure.

 

 

Scaffolding Transom

Scaffolding Transom

 

 Transoms rest upon the ledgers at right angles forming a much more rigid structure. Main scaffolding transoms are placed next to the standards, they hold the standards in place and provide support for boards; intermediate scaffolding transoms are those placed between the main scaffolding transoms to provide extra support for scaffolding boards.

 

 

Scaffolding Cross Braces

Scaffolding Cross Braces

 

Scaffolding cross braces are a further brace fitted to the scaffolding standards to increase rigidity, these are placed diagonally from ledger to ledger. If the scaffolding braces are fitted to the scaffolding ledgers they are called gin wheels. To limit sway a facade brace is fitted to the face of the scaffold every 30 metres or so at an angle of 35°-55° running right from the base to the top of the scaffold and fixed at every level.

 

Right angle coupler

Right angle coupler

 

Right-angle couplers join ledgers or transoms to standards, putlog or single couplers join board bearing transoms to ledgers – Non-board bearing transoms should be fixed using a right-angle coupler. To connect tubes at any other angle scaffolding swivel couplers are used. The actual joints are staggered to avoid occurring at the same level in neighbouring standards.

 

The spacing of the basic elements in the scaffold is fairly standard. For a general purpose scaffold the maximum bay length is 2.1 m, for heavier work, where the structure has to carry a greater load, the bay size is reduced to 2 or even 1.8 m while for inspection a bay width of up to 2.7 m is allowed.

 

Transom spacing is determined by the thickness of the boards supported, 38 mm boards require a transom spacing of no more than 1.2 m while a 50 mm board can stand a transom spacing of 2.6 m and 63 mm boards can have a maximum span of 3.25 m. The minimum overhang for all boards is 50 mm and the maximum overhang is no more than 4x the thickness of the board.

Scaffolding Tubes

Tuesday, September 22nd, 2009
Scaffolding Tubes

Scaffolding Tubes

Scaffolding Tubes are made of either aluminum or steel. Generally if they are steel they are painted either ‘black’ or they are galvanised. The scaffold tubes come in a variety of lengths and a standard diameter of 48.3 mm. (1.5 NPS pipe). Scaffolding tubes are generally bought in 6.3 m lengths and can then be cut down to certain typical sizes.

The main difference between the two types of scaffolding tubes is the lower weight of aluminum scaffolding tubes (1.7 kg/m as opposed to 4.4 kg/m) and also a greater flexibility. Which means the advantage of steel over aluminum is its greater resistance to force.

Scaffolding

Tuesday, September 22nd, 2009

 

Restoration... Hagia Sophia scaffolding

Restoration... Hagia Sophia scaffolding

 

Scaffolding is a temporary frame used to support people and material in the construction or repair of buildings and other large structures.  The American National Standards Institute describes scaffolding as “a temporary elevated or suspended work unit and its supporting structure used for supporting worker(s) or materials, or both,”

 

Usually this is a modular system of metal pipes (termed tubes in the UK). These are known as tube and fitting scaffolds. The process of building the scaffold, erection and dismantling is called striking. In other countries alternative materials have been used, Asia still uses Bamboo for example.  If you need scaffolding the best place to start is www.tuxebo.co.uk.  Tuxebo helps you get scaffolding quotes fast and cheaper.