TRADStair User Guide

TRAD Stair Tower User Guide

Page 1

HIRE & SALES LTD

TRAD STAIR TOWER USER GUIDE Providing quality products and services at a competitive price


©Trad Hire and Sales Limited 2010

Page 2

Table of Contents

About TRAD Hire & Sales 3

About TRAD Stair Tower 4

TRAD Stair Tower & Safety 5

Manual Handling 6

Safety on Site 7

General Rules for Safety 8

Components 9

Erection Guidance 17

Basic Erection Sequence 18

Basic Dismantling Procedure 29

Anchorage and Tying 31

Loading 31

Personnel Capacities 32

Safe Working Heights 33

Please Note

• You should read and ensure you understand this manual in its entirety prior to commencing work.

• Only trained and competent operatives should erect, dismantle or modify TRAD Stair Tower systems at any time.

Guidance Note

This manual is valid only for the use of Genuine TRAD Stair Tower manufactured and supplied by TRAD Hire and Sales Limited.


Page 3

About TRAD Hire and Sales Ltd

TRAD Hire & Sales is one of the UK’s market leaders for the supply of system scaffolding, scaffold tube, fittings, boards, stair towers, temporary roofing systems and associated equipment. All the products we stock are of the highest quality and comply fully with all relevant British or European Standards. In addition, with our commitment to exceeding all safety standards, all our products, whether sourced internationally or within the UK are subject to thorough testing by qualified external UK testing bodies. From the smallest requirement to complete hire or sale packages – our UK‐wide network of depots have the resources and capabilities to meet the demands from the smallest to the largest projects. TRAD Hire & Sales Ltd. is a full non‐contracting member of the National Access and Scaffolding Confederation (NASC) and is a fully accredited ISO 9001 company.



Page 4

About TRAD Stair Tower

TRAD Stair Tower is an independent access stair system designed to provide safe an efficient access to on‐site work locations. The TRAD Stair Tower is comprised of high quality manufactured prefabricated components. The Stair Tower is assembled from Steel Standards, Ledger Beams, Purlin Rails / Frames, Stair Flights, Landings, Guardrails and Handrails. The TRAD Stair Tower is a flexible and versatile system designed for use as an independent structure or for integration into other Scaffolding Systems or Stagings.

All components are manufactured from quality galvanised steel conforming to current British and European standards. All components are marked with TRAD identification and month / year of manufacture to provide full traceability. Components are subject to regular testing by independent and approved UK testing facilities.

This guide sets out, for the user, the basic system components and configuration. The Stair Tower system is flexible and versatile in use. For further information on TRAD Stair Tower components and applications please contact your nearest TRAD Hire & Sales branch (locations are detailed on the rear cover of this guide)

TRAD Stair Tower offers many benefits including:

Strength ‐ TRAD Stair Tower design makes it extremely robust with permissible loads (personnel) exceeding those of alternative Stair Systems.

Speed: The system design makes the TRAD Stair Tower faster and simpler to build then

alternative Stair Systems. Flexibility: TRAD Stair Tower can be used as an independent stair or in conjunction with

traditional Tube and Fitting Scaffolding or System Scaffolding. Cost Savings: The TRAD Stair Tower is easy to assemble and is designed to maximise

productivity and improve efficiency on site TRAD Stair Tower is manufactured to the highest possible standards thereby ensuring the quality of each item. TRAD Stair Tower is tested and designed in line with the ISO 9001 series of quality management systems. Furthermore, TRAD Stair Tower and it’s associated products offer compliance with the following: ‐ BSEN 12810 Part 1:2003 Façade scaffolds made of prefabricated components: Product

Specifications BSEN 12810 Part 2:2003 Façade Scaffolds Made of Prefabricated Components: Particular

Methods of Structural Design BSEN 12811 Part 1:2003 Scaffolds ‐ Performance Requirements & General Design BSEN 12811 Part 2:2003 Information on Materials BSEN 12811 Part 3:2003 Temporary Works Equipment ‐ Load Testing BSEN 39 Part 1:2009 Metal Scaffolding, Couplers and specials Couplers in Steel BSEN 74: 2007 Couplers for use in scaffolding


Page 5

TRAD Stair Tower and Safety

Competence of Erectors

Competence of individuals working at height is now a direct requirement of the current Work at Height Regulations. Consequently, employers have a duty to ensure that all individuals involved in the erection, modification or dismantling of any scaffolding equipment have received the necessary training to enable them to execute their work in a safe manner. This User Guide and availability of specific and dedicated training courses for TRAD Stair Tower system (via our nationally accredited training partners) ensures that all users have access to achieve the requisite level of competence. For further information please contact your local TRAD Hire & Sales Ltd. Depot, details of which can be found on the rear cover of this guide. Work at Height/Fall Prevention

The current edition of the Work at Height Regulations places a duty on employers to protect individuals from harm. Scaffolding inevitably carries a risk of falls from height and consequently, it is of paramount importance that a safe system of work be adopted during any scaffold activity. It is therefore strongly recommended that the procedures outlined in the NASC’s guidance note SG4 – ‘Preventing Falls in Scaffolding and Falsework’ are followed. SG4 describes several safe methods of work, including the use of collective fall protection systems such as the advanced guardrail and the scaffolder’s step.

Harness and Lanyard Anchor Points

To ensure the safety of TRAD Stair Tower erectors, it is important that fall protection equipment is only attached to those components that are capable of withstanding any likely imposed loads. This section details the key components and their ability to take attachment (in preferential order). Please note that all scaffolds must be erected in accordance with this guide to be deemed as acceptable for attachment. Attachment can be made to the following components! TRAD Stair Tower Ledger Beam –

highest available point and secured at both ends

TRAD Stair Tower Purlin Frame / Purlin Rail (highest available point) and secured at both ends Attachment must not be made to : - Ledger Beams or Purlin Frames /

Purlin Rails not secured at both ends.

- Standards



Page 6

Rescue of Suspended Casualties

While the current Work at Height Regulations requires that work at height be carried out safely, they also require that contingency plans be made for any eventuality, this extends to making plans to rescue personnel suspended by fall arrest equipment. Provision should be made to ensure that personnel are fully trained to use any equipment that may be required to execute a rescue of any suspended casualties. Note: Always refer to NASC guidance notes SG4 & SG19 (SG19 – ‘A Guide to Formulating Rescue Plans’).

Manual Handling

The following basic rules should be adhered to when manually handling the TRAD Stair Tower system and associated components. Plan lay down/storage areas in advance to reduce the distance materials have to be manually handled. Always check the transit route before manual handling to ensure that it is suitable and free from obstructions and any tripping hazards. When handling long materials beware of damage to property, overhead electric lines, other people and moving vehicles. Only tackle loads that can be reasonably handled by the individuals involved – i.e. consider personal physical capabilities. Manual handling operations should be eliminated where possible by using mechanical handling equipment and manual handling aids whenever possible. These include light‐lines, gin wheel, forklifts and cranes etc. Use the correct knots and hitches if using rope to lift equipment. Always use the correct kinetic handling technique: ‐

• Feet on a firm level base a comfortable distance apart. (Approx. 300mm) • Use your legs and not your back to bend. • Raise your head slightly and tuck in your chin to keep your spine straight. • Avoid twisting with the trunk of the body.



Page 7 of 36

As is the case with any scaffold erection, dismantling or modification, consideration must always be given to those that may be affected by the works being carried out. To ensure that the highest standards of safety performance are maintained, consideration should be given to the following: ‐ 1. If the scaffold is on rough or uneven

ground, ensure that it is erected on adequate timber sole boards that are properly levelled and bedded and that the ground is capable of withstanding proposed loadings.

2. All Stage Landings and Stair Flights must be free from obstructions, trip hazards or projections. Where there are risks of items falling from Stage Landings the TRAD Stair Tower Toe Board should be considered for use.

3. Do not load Stage Landings with

materials. All materials are to be stored on scaffolds or loading towers.

4. All scaffolds require adequate bracing and ties. Neither should be removed without giving consideration to firstly installing alternative bracing or ties, to ensure the continued safety of the scaffold.

5. All scaffolds must be erected in strict

accordance with this user guide any

configurations out with this guide including sheeting, netting or other similar wind sails should be referred to a person competent in the design of TRAD Stair Towers.

6. Any unauthorised interference should be

immediately reported to site management with any incomplete or unsafe parts of the scaffold being clearly marked and access restricted.

7. All TRAD Stair Tower components require

visual inspection before use. No damaged equipment should be used within the scaffold structure. Any equipment found damaged should be immediately set aside in a quarantined area, clearly marked and senior management informed. Maintenance and repair procedures should only be carried out by qualified / approved personnel.

8. Always wear appropriate PPE with Hi‐Vis

where required.

Safety on Site



Page 8

Always

Always ensure all risk assessments and

method statements have been carried out, communicated to those concerned and understood.

Always ensure that there is adequate

storage for the materials.

Always ensure that there is clear access to the work area and that the ground is level and suitable to accept the scaffold.

Always ensure all who erect, adapt and dismantle the scaffold are trained and competent to do so.

Always work to current SG4 guidelines.

Always ensure that there are adequate

tying points. Always ensure that Stair Flights and

Stage Landings are free from obstructions or trip hazards.

Always ensure scaffold inspections are

carried out and recorded as per current legal requirements.

Always ensure that all defects are

notified to the site management immediately.

Never

Never remove guardrails or toe

boards.

Never remove ties without prior approval.

Never remove restrictions or warning signs from the scaffold structure.

Never undermine the scaffold by

digging trenches under or near to the base.

Never add sheeting or netting without

prior approval.

Never let untrained persons erect, modify or dismantle the scaffold.

Never use damaged materials.

Never allow unqualified / unapproved

personnel to repair damaged equipment

Never load directly on to the access scaffold’s working platform (always use a loading tower).

Never load equipment directly onto

the Stair Tower system.

General Rules for Safety

REMEMBER

SAFETY IS NO ACCIDENT DON’T RISK IT IF IN DOUBT – ASK!

The information given in this TRAD Stair Tower user guide relates solely to TRAD Stair Tower equipment supplied by TRAD Hire & Sales Limited.


Page 9

TRAD Stair Tower Components

Standards These form the vertical members of the Stair Tower. 3.0m and 2.0m are the common sizes. Each standard has connection / node points (lugs) every 500mm Code Length Weight 159502 3.0m 18.8 kg 159503 2.0m 12.45 kg .

Beams The TRAD Stair Tower is built using 3.0m and 1.6m ledger beams at platform / landing level. The 3.0m beam acts as the transom beam and the 1.6m beam acts as the ledger beam. The landings are fitted to the ledger beams prior to installation of the flights. Code Length Weight 159516 3.0m 17.2 kg 159519 1.6m 9.66 kg



Page 10

Purlin Rails These provide a single guardrail function and are available in 3.0m, 2.16m and 1.6m sizes. Code Length Weight 149109 3.0m 9.77 kg 159544 2.16m 7.95 kg 149111 1.6m 5.7 kg .

Purlin Frames Provide double handrail functionality for stair flights and at the stage landing level. Available in 3.0m and 1.6m sizes. Code Length Weight 159530 3.0m 13.6 kg 159532 1.6m 9.68 kg


Page 11

Entrance Steps Provides initial step access to first level stage landing. Code Length Weight 159554 1.6m 16.32 kg .

Stair Flights Provide interconnecting stair access to each lift of the Stair Tower. Access and egress to the stair flight via connected stage landing. Available in 2.0m, 1.5m and 1.0m sizes. Code Length Weight 159546 2.0m 53.66 kg 159547 1.5m 39.06 kg 159548 1.0m 39.21 kg



Page 12

Stair Handrails Provides double handrail for all stair flight sizes. Available in 2.0m, 1.5m and 1.0m sizes. Code Length Weight 159549 2.0m 10.73 kg 159550 1.5m 9.90 kg 159551 1.0m 10.27 kg .

Stage Landings Fitted to the ledger beams to provide connection points for stair flights. Provide access and egress points at working lifts. Code Length Weight 159552 1.6m 28.2 kg .


Page 13

Handrail Posts Fitted to stage landing to provide connection points for stair handrails. Code Length Weight 159553 1.0m 6.18 kg . .

Clip On Posts Fitted to ledger beam and connected to 2.16m guardrails when providing access or egress at side of tower. Code Length Weight 159542 1.0m 7.40 kg



Page 14

Folding Guard Frame Provides double handrail on stage landing at entrance to Stair Tower. Code Length Weight 159556 N/A 9.61 kg .

Base Jack Base jack incorporating base plate provides levelling foundation for the standards of the TRAD Stair Tower. Provides means of vertical adjustment of the standards to ensure that the ledger beams are level. Code Length Weight 127005 650mm 3.4 kg .


Page 15

Guardrail Frame Fitted to stage landing on final lift of Stair Tower. Completes double handrail on top stage landing. Code Length Weight 159555 N/A 8.5 kg .

Stair End Toe Board Stair Side Toe Board



Page 16

Stair Top Toe Board

Toe Boards Fitted to edge of Stage Landing to prevent materials or operatives’ falling or slipping off the platform.

Code Weight Stair End Toe Board 159625 6.5kg Stair Side Toe Board 159630 2.9kg Stair Top Toe Board 159635 2.2kg

Additional Components Additional Components outside the standard component set for the TRAD Stair Tower System may be required to enable use in accordance with this user guide. These components will normally constitute loose Scaffold Tube compliant to EN39 standard and Scaffold Couplers compliant to EN74 standard.


Page 17

Erection Guidance

Introduction

This section describes the basic erection and dismantling procedures for the TRAD Stair Tower.

As with all scaffolding, only trained, competent operatives should erect, dismantle or modify the TRAD Stair Tower at any time.

TRAD Hire & Sales Ltd. recommends, that as a minimum, the working practices for all scaffold activities set out in the NASC’s document SG4 – ‘Preventing Falls in Scaffolding & Falsework’, are applied at all times.

Prior to commencing work, make sure all method statements, risk assessments and permits are in place and that suitable tie points are available.

Ensure that the ground is level, firm and capable of taking the imposed load of the completed stair tower. Where required, use sole boards / spreader plates of a suitable size to spread the load over the ground.

Ensure that the structure against which the tower is erected and upon which it relies for it’s stability is a sound and inherently stable structure.

Set out the Stair Tower according to the ground levels and working platform heights required. Start constructing the tower from the most convenient point and, where practicable, at the highest ground level.

It is recommended that work to erect and dismantle the Stair Tower be carried out by a minimum of two operatives.

If using an advance guardrail or scaffolder’s step information relating to the use of these products should be obtained from the original supplier.

Ensure that the recommended harness and lanyard guidance notes are observed at all times (See section TRAD Stair Tower and Safety).



Page 18

Basic Erection Sequence

1

For base jacks as shown, set out sole plates at position of standards, ledger beams and transom

beams. Place base jacks onto sole plates, adjust to estimated final height.

2

Place standard on base jacks, ensure that pockets are running in direction as shown (low pocket,

1.65m direction, high pocket 3.05m position).


Page 19

3

Connect 3.05m ledger beam to higher level pockets. Connect 1.65m ledger beams to lower level

pockets.

4

Engage all locking catches as you proceed.



Page 20

5

Check distance from structure.

6 Level first lift following clockwise direction. Level by adjusting base jacks as necessary.

7

Check base lift is square using a tape measure.


Page 21

8

Place first landing (A), on ledger beams as shown. Place stage landing (B), at opposite end of bay

(foot lift).

Install second level of ledger beams. Next landing (C), is located by working off stage landing (B). The

landing on this lift, and all further lifts, are initially positioned on ledger beams approximately 0.5m

from end of bay.

9

Fit entrance step to tower.



Page 22

10

The stair tower must be anchored to the structures at each platform level on both ends (inner and

outer standards) using scaffold tube and couplers.

A


Page 23

B

C

D



Page 24

E

11

Stair flight is positioned vertically and located into pockets of lower landing (11A & 11B). Flight is

then lowered onto landing above (11C) and pushed along (11D) until top of stair flight is fully located

into pockets of upper landing (11E).

Note: At this stage check top and bottom of stair is fully engaged into both landing pockets.

Stairflights should be erected for a clockwise ascent.

12

Fit guardrail frames and guardrails to the outside face of the stair flight.


Page 25

13

Uppermost erector clips to mid point of ledger beam. Both erectors then fix stair handrail post into

top and lower landings. Then, stair handrail is located into pockets of posts and locking catch

engaged.

14

Fit folding guard frame into handrail post and standard at entrance of stair.

15

Re‐position stage landing onto next lift directly above lower landing.



Page 26

16

Erector 1 proceeds up stair flight and fits temporary clip‐on post to ledger beam close to stage

landing. Erector 1 then hooks to ledger, and, using clip‐on post for support, he climbs onto stage

landing.

Note: Clip‐on post is only used to facilitate climbing to exposed landing.

17

Erector 2 proceeds up stair flight onto landing, hooks onto ledger beam close to standard.

18

Next standards are added to all four legs. Temporary clip‐on post may now be removed to a safe

place until it is required again (e.g. end 1.65m ledger beam).


Page 27

19

Fit guardrail frames to face and end of tower as shown. Fit ledger beams to next lift required (1.5m

or 2.0m). Re‐hook to upper ledger near standards.

20 Ties should be fitted to structure and tower at each level before erecting next lift.

21 For further lifts repeat procedures 8, 11‐13, 15‐20 until reaching final exit level or mid exit points.



Page 28

22

Entrance/exit at top of tower. Erector 1 is safely standing on landing and hooked on to 1.65m ledger

beam, fits 3.0m guardrail frame with erector 2 safely standing on stage landing at opposite end of

tower, hooked onto 1.65m ledger beam. Erector 1 then fits top guard frame into handrail post and

landing as shown.

23

FOR SIDE EXIT ‐ Erector 1 is safely standing on landing and fits clip‐on post to inside ledger beam.

Erector 2 standing on stage landing at opposite end of tower hooked onto 1.65m ledger beam. Both

erectors then fit 2.16m guardrails or 2.16m guardrail frame into clip‐on post and standard ensuring

locking catches are engaged. Means of access/egress at side of tower is then complete.


Page 29

24

FOR END EXIT ‐ Erector 1 is safely standing on landing. Erector 2 standing on stage landing at opposite end of tower hooked onto 1.65m ledger beam. Both erectors fit 3.0m guardrail frame at

each side of tower. Remove 1.6m guard from landing position. Means of access/egress at end of

tower is then complete. For construction of the TRAD Stair Tower with the 3.0m face parallel to the

structure or scaffold (side exits). Using tube and couplers, the tower should be tied to the structure

below each lift position (except first lift) through both inside and outside standards.

ACCESS POINTS ‐ It is only possible to have a side access point (3.05m) in a 2.0m lift. Access

to/from end of tower (1.655m) is not restricted, but 1.65m ledger beam

May have to be raised to create headroom when access lift is less than 2.0m.



Page 30

25 Toe Boards‐ Toe Boards are optional and can be fitted on completion of the Installation of the stage landing and the upper and lower stair flights. Side toe boards are hooked over the ledger beams by the Erector and the End toe boards are fitted to the Stair Tower standards by Inserting the end hooks into the lugs. Top toe boards are fitted to by means of connecting the toe board hooks around the guard frame and into the lugs of the handrail post.


Page 31

Basic Dismantling Procedure

Step 1

Prior to commencing work, make sure all method statements, risk assessments and permits are in place. Step 2 Check that the Stair Tower is still in the properly erected condition. Make sure that all components and ties have not been interfered with and all platforms are clear of any loose material and debris prior to dismantling. Report any problems to site management immediately. Step 3 Decide on the safe lowering method by which the components shall be removed to the ground, for example hand to hand, crane, hoist, forklift truck or hand‐line. Under no circumstances should ‘bombing’ be used to lower equipment. Once the components are safely on the ground they should be stacked neatly ready for transportation. Step 4 All components fixed above the top platform’s guardrails should be removed. Components should then be lowered to ground level. Step 5 The top working platform can now be dismantled paying particular attention to the current NASC guidance note SG4‐‘Preventing Falls in Scaffolding and Falsework’. If using an advance guardrail or scaffolder’s step information relating to the use of these products should be obtained from the original supplier. Step 6 Remove any toeboards and associated brackets and again transfer to the ground. Step 7 Removing all guardrails and any ‘topped out’ standards as you go, move progressively towards the stair flight. Components should then be lowered to ground level.



Page 32

Step 8 Remove handrail posts and handrail simultaneously (two erectors) and lower to ground level. Step 9 Unhook the stair flight, remove and lower to ground level. Step 10 From Erection Platform / Stage landing remove the upper level stage landing and lower to ground level. Step 11 Unsecure the thumblocks of the ledger beams. Remove all four ledger beams progressively and lower to ground level. Step 12 Repeat steps 5 to 12 dismantling and lowering the components in the sequence described. Note: Ties should only be removed when they prevent further dismantling. Step 13 At ground level, work progressively towards the final stage landing and entrance step. Remove ledger beams and purlin rails / purlin frames whilst holding standards so that they do not become unstable. Remove the standards from the base jacks when they are no longer attached. Step 14 If any element of this dismantling sequence cannot be complied with please seek advice.


Page 33

Anchorage & Tying‐In

The TRAD Stair Tower must be anchored to the adjacent structure.

The Tower should be tied to this structure at each lift (i.e. 2m vertical centres) using horizontal ties at each side that securely fix to the existing structure and to the inner and outer standards.

Where the shorter 1.6m face of the Tower is constructed parallel to the existing structure, additional ties are required. These ties should be applied at each lift from the outer standards at 45 degrees back to the existing structure. These additional ties are to be securely fixed to the existing structure and this fixing is assumed to be capable of resisting horizontal forces both parallel and perpendicular to the plane of the wall.

All access scaffolds will impose forces upon the structure to which they are fixed through their ties. There should be an initial assessment with regards to the ability of the structure to sustain the loads either globally, due to its own instability, or locally as a result of defective finishes. Loadings from the ties into the supporting structure are dependant upon the live loading to the working platforms, the height of the scaffold and, in the majority of cases, the wind loading imposed upon the scaffold and its cladding status. For guidance with regards to the design of ties into building facades we would refer you to Section 5 of TG20:08 or to the TRAD Hire & Sales Ltd Technical Services Department or a competent temporary works designer.

Tie Connections

Standard tube and fittings are used to form the tie connection in conjunction with a proprietary tie system. Appropriate length tubes are to be fitted to both the standards of the TRAD Stair Tower structure.

In addition to masonry anchors, box ties, through ties or girder may also be used to ensure the stability of the TRAD Stair Tower system. (Where suggested configurations cannot be used, qualified design input must be sought).

Load Data for the TRAD Stair Tower

In accordance with the requirements of BS EN12811 the Design load for the TRAD Stair Tower is 1 kN/m2, or 1.5 kN positioned in worst‐case position for element of tower under inspection.

Throughout the calculations for the maximum design load on any standard for the TRAD Stair Tower has been taken as 45.24 kN where the 3m face is parallel to the structure and 29.07 kN where the short (1.6m) face is parallel to the structure based upon the use of Ledger Beams to both long and short faces of the tower at every landing location.



Page 34

Personnel Capacities for the TRAD Stair Tower

The Personnel Capacities tables are designed to provide guidance on the recommended number of personnel permitted on the TRAD Stair Tower by the height of the tower. For the purposes of this table one person is assumed to weigh 100kg, exerting a force of approximately 1kN.

This table is limited to a maximum area load of 3 kN/m2, for practical reasons.

TRAD STAIR TOWER

Stair Tower Height Max No. Personnel

2 m 4 m 6 m 8 m 10 m 12 m 14 m 16m 18 m 20 m 22 m 24 m 26 m 28 m 30 m 32 m 34 m 36 m 38 m 40 m 42 m 44 m 46 m 48 m 50 m

28 35 40 47 53 59 65 71 77 84 90 96 102 108 114 121 117 117 113 112 108 106


Page 35

Safe Working Heights for the TRAD Stair Tower

The TRAD Stair Tower Safe Height Tables are based on a maximum height of 30m, heights above this are possible but these should be referred to a competent temporary works engineer. This TRAD Stair Tower User Guide utilises wind loading in the preparation of its safe working height tables for access scaffold. These tables are limited to “S” values above 20 and below 40. Where localised conditions result in “S” values outside of these parameters the wind velocity pressures may either be lower than or exceed those utilised within the calculations from which the tables are derived. Scaffolds located to the edges of cliffs or escarpments, in coastal locations or to tall structures surrounded by other tall structures, which may cause funnelling of the wind pressure, are all susceptible to significant increases in wind pressure due to local effects. In these instances it is recommended that advice is sought from a competent temporary works engineer.

For the purposes of this guide the Stair Tower is assumed to be unclad and free from netting and sheeting, such that the only area presented to the wind is that of the components of the Stair Tower.

The safe height tables and section capacities contained within the This TRAD Stair Tower User Guide are based upon live loading from the intended use only. Additional loading may accrue on the working platforms or components as a consequence of atmospheric precipitations such as ice, snow, sand and dust. The working processes may also cause debris such as sand, grit or demolition debris to accumulate on the working platforms or components, which will also increase the live loading above that allowed for. Where this is seen to occur or is known will occur further guidance should be sought from a competent temporary works engineer, which may result in a downgrading of the Load Class of the scaffold.

Town Sites

Any site that is at least 2km inside a town terrain, shielded by buildings within 100m an where the average height of the surrounding buildings are 5m or more then this site is classified as a ‘Town’ site.

Country Sites

Any site that falls outside the scope of the description of the ‘Town’ site.

Procedures and guidance for determining maximum safe heights are available in TG20:08 Volume 1.



Page 36

B11043 – TRAD ACCESS TOWER 3.0m (Long) Face Parallel to Building Maximum Tower Height (m)

S Value to be ascertained subject to site

In Country

In Town

20 30 30

24 30 30

28 24 24

32 6 8

36 ‐ 4

40 ‐ ‐

Derived from Out of Service Condition – Critical up to 30m

1.6m (Short) Face Parallel to Building

Maximum Tower Height (m)

S Value to be ascertained subject to site

In Country

In Town

20 30 30

24 30 30

28 30 30

32 30 30

36 30 30

40 20 20

Derived from Out of Service Condition – Critical up to 30m

Documents

TRADStair User Guide