Stairs Joinery

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Carpentry & Joinery Phase 2 Module 4

Unit 15 4

List of Figures

Figure 1. Measuring Rise and Going............................................................................ 13

Figure 2. Measuring headroom .................................................................................... 14

Figure 3. Change of Direction...................................................................................... 15

Figure 4. Landings........................................................................................................ 16

Figure 5. View showing steps on Storey Rod .............................................................. 17

Figure 6. View of stair showing: Steps, Carriage, Glue Block, Rough Bracket .......... 18

Figure 7. View of section through stairs ...................................................................... 18

Figure 8. View of top newel post fixed to trimmer ...................................................... 18

Figure 9. View of method for fixing handrail bolt ....................................................... 19

Figure 10. View of marking out a cut string .............................................................. 19

Figure 11. Closed string staircase, jointing of newel post to the string and handrail. 19

Figure 12. View of stairs showing the required headroom ........................................ 20

Figure 13. View of closed string staircase: ................................................................ 20

Figure 14. View of open or cut string showing method of construction.................... 21

Figure 15. View of methods for jointing steps........................................................... 21

Figure 16. View showing a method for cramping up stairs ....................................... 22

Figure 17. Building regulation staircases (straight flights) ........................................ 23

Figure 18. Stair parts .................................................................................................. 24

Figure 19. Templets.................................................................................................... 25

Figure 20. Landing details.......................................................................................... 26

Figure 21. Stair detail ................................................................................................. 27


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List of Tables

Table 1. Rise, Going and Pitch ................................................................................... 13


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Document Release History

Date Version Comments

October 2006 V.1.0.


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Module 4 Machinery and Joinery

Unit 15: Stairs

Duration 34.5 Hours

Learning Outcome

By the end of this unit each apprentice will be able to:-

Identify the various types and designs of stairs and describe method of

construction.

Identify types and sizes of timber used in the manufacture of stairs.

Define method of setting out, marking out, fixing thread to string and fixing

newel post to string.

Identify correct method of cramping up and squaring of stairs.

Calculate rise/going.

Calculate no. of steps.

Summarise building regulations related to stairs.

Set out, write a cutting list, mark out and construct closed string staircase withnewel.

Assemble sand and finish stairs.

Identify correct method of finishing around stair well.

Identify correct method for protecting stairs on site.

Operate power tools.

Identify hazards and apply safe working practices.

Identify correct method for disposal of waste and use good house keeping

practices.


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Key Learning Points

RK Types of stairs.

RK Type and sizes of timber used in stairs construction.

SK RK Setting out/marking out.

SK RK Fitting and fixing newel posts.

RK Cramping up and squaring stairs.

Sk Calculating rise/going.

Sk Calculating number of steps.

RK Building regulations re stairs.

RK Preparation of cutting list.

RK Purpose of cutting list.

RK Layout of cutting list.

RK Explanation of terms.

RK Meaning of job numbers part numbers.

RK Need for accuracy when listing.

Sk Assembling, sanding and finishing stairs.

RK Finishing to stair well.

RK Protecting stairs on site.

Sk Use of tools.

Sk Use of portable router.

Sk Use of cordless drill.

Sk Use of orbiter and belt sander.

RK H Identify hazards/machines and power tools.

RK H Impact of poor waste disposal on environment.

P Planning of stairs.


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Training Resources

Setting out board

Setting out equipment

Drawing

Tools

Timber

Exercise

Complete exercises in this document.


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Stairs

The main function of a stairs is to get from one floor to another. Stairs may be classified

according to their shape in elevation or plan.

The timber staircase may be divided into two classifications:1. Closed strings with or without newels.

2. Open strings with or without newels.

Closed String Staircase

A closed string staircase is constructed from a series of steps closed on each end by a

string. The step is constructed of a thread and riser which are connected together by

housing and a pair of glued blocks at the back to hold the stairs rigid.

Construction of Closed String Staircase

The construction of a closed string staircase is as follows:

1. The steps are constructed in the manner explained before.

2. The steps are then placed into the housed-out string and the second string placed on

top.

3. Cramps or other equipment are then placed on the top string and cramped up.

4. The staircase is then squared.

5. Wedges are then driven in from the back of the threads and risers.

6. The backs of the threads are then screwed to the riser.

7.

The stairs is then ready for cleaning up.Note: If newels are required they are fitted after the stairs is wedged up.

Setting out Stairs

There are four important points to remember when setting out a stairs.

1. Sufficient head room must be provided, 2m minimum and this is measured vertically

from the face of the thread.

2. Public buildings have stair widths from 1.4m - 2m, but in domestic buildings stair

widths range from 800mm - 1m.

3.

Height of handrail measured from face of thread should be 760mm - 860mm and theheight of the landing should be 950mm - 1.12m.

4. (a) Going not less than 220mm.

(b) Rise not more than 220mm.

(c) 2R + G should be not less than 550mm

(d) 2R + G should be not more than 700mm.

(e) Pitch of a private stairway shall not be more than 42.

Operations Involved In Building a Straight Flight of Stairs

1. Take total rise and going on the site.

2. Calculate rise and going per step.3. Prepare cutting list.


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4. Make pitch board and tread and riser sticks.

5. Using these and a margin template, mark out strings, treads and risers.

Stairways and Ramps

Stairways, ladders and ramps K1 Stairways, ladders and ramps shall be such as to affordsafe passage for the users of a building

Introduction

The requirement in K1 does not apply to means of access outside a building unless they

are part of the building e.g. it would apply to entrance steps attached to a building but not

to steps in site works leading up to the building.

Additional requirements may be necessary for access routes which form part of:

1. Means of escape in case of fire (see Technical Guidance Document B);

2.

Means of access for disabled people (see Technical Guidance Document M).This section of the Technical Guidance Document is divided into two sub sections;

stairways and ramps.

Stairways and Ladders

Guidance

I.S. 158: 1987 Closed String Wood Stairs covers requirements for quality, design andconstruction of stairs in wood with closed strings for internal use in dwellings. It does not

apply to stairs with open risers.

BS 5395: Part 1 1977 (1984) Code of practice for the design of straight stairs deals withthe design and construction of stairs in different materials for all types of buildings. It

includes dimensional coordination, safety, means of escape, lighting, durability,

constructional aspects, protection and painting, maintenance and cleaning, with

illustrations and bibliography.

BS 5395: Part 2:1984 Code of practice for the design of helical and spiral stairs covers

materials, dimensions, fire protection, and means of escape. It refers to:

BS 5395: Part 1 for dimensional coordination, safety measures, acoustics and lighting.

Appendices cover geometry and load tests.

BS 5395: Part 3:1985 Code of practice for the design of industrial type stairs, permanent

ladders and walkways covers factors affecting choice of means of access or escape,

structural materials, dimensions, safety equipment, platform and walkway floor loads.

Refers to

BS 5395: Parts 1 and 2 for general design of stairs and to BS 6180 for general design of

protective barriers.

BS 6180:1982 Code of practice for protective barriers in and about buildings gives advice

on general design and construction of balustrades and protective barriers in and about

buildings.

BS 585: Part 1:1989 Specification for stairs with closed risers for domestic use, including

straight and winder flights and quarter or half landings includes plywood risers andtreads, edge-to edge jointed timber and glue-laminated wood components. It contains


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recommendations for fixing stairs on site and for the design of stairs with winder flights.

Open risers, stairs wider than 1220 mm and flights having a total going exceeding 3800

mm are excluded.

BS 585: Part 2: 1985 Specification for performance requirements for domestic stairs

constructed of wood-based materials covers straight flight stairs and stairs with quarter

and half landings intended primarily for use inside ones family dwelling.

BS 4211: 1987 Specification for ladders for permanent access to chimneys, other high

structures, silos and bins covers Class A steel ladders, for permanent attachment to

chimneys and other structures and Class B ladders for permanent attachment to silos, bins

and agricultural plant, which may be formed of steel or aluminum.

The following paragraphs give some guidance to good practice insofar as it relates to

non-complex buildings of normal design and construction.

Term Meaning

Flight Is a part of a stairway which consists of a step or consecutive steps.

Going Means the horizontal distance between the nosing of a tread and the

nosing of the tread or landing next above it.

Pitch Means the angle between the pitch line and the horizontal.

Rise Means the vertical distance between the top of a tread and the top of the

tread, landing or ramp next above or below it.

Tapered step Means a step the nosing of which is not parallel to the nosing of the step

or landing next above it.

Tread Means the upper surface of a step within the width of a stairway.


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Public stairway means a stairway used by large numbers of people at one time, e.g. in

places of public assembly and includes a stairway used by people with ambulatory

difficulties, e.g., in hospitals, childrens homes.

The sum of twice the rise plus the going (2R + G) should be between 550mm and

700mm, with an optimum of 600mm.

1.1.5 For tapered treads, the going should conform to paragraphs 1.1.3 and 1.1.4 when

measured as follows:

1. If the flight is narrower than 900 mm, measure in the middle.

2. If the flight is 900 mm or wider, measure 270 mm from each side

In addition, the going should measure at least 75 mm at the narrow end. Where

consecutive tapered treads are used, a uniform going and rise should be maintained.

Construction of Steps

1.1.6 Steps should have level treads. Steps may have open risers but in such cases thenosing of any tread should overlap, on plan, the back edge of the tread next below it by at

least 16 mm.

1.1.7 Stairways which have open risers should be constructed so that a 100 mm diameter

sphere cannot pass through the opening between adjacent treads.

Headroom

1.1.8 Headroom over the whole width of any stairway, measured as shown in

Diagram 2, should generally be not less than 2 m. In the conversion of a loft where space

is limited, headroom measured at the centre of the stairs should be not less than 1.9 m but

may reduce to not less than 1.8 m at the side of the stairway if there is a minor projection.

Figure 2. Measuring headroom


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Figure 3. Change of DirectionWidths of Stairways

1.1.9 BS 5395:1977 recommends 800 mm as the minimum unobstructed width for a

private stairway and 1000 mm for semi-public and public stairways. It also recommends

that a stairway which is more than 1800 mm in width should be divided by handrails intosections of not less than 1100 mm and not more than 1800 mm wide. See Technical

Guidance Document B for requirements for stairways which form part of means of

escape and Technical Guidance Document M for requirements for stairways providing

access for disabled people.

Length of Flights

1.1.10 There should be not fewer than three and not more than 16 risers in any one flight,

except that, between the external door of a building and the ground or an access balcony,

and at the foot of a stairway serving a single dwelling, one or two risers may be

permitted.1.1.11 In places of assembly to which large numbers of people have resort, there should

be no more than two consecutive flights without a change in direction of at least 30

between flights. If there are more than 12 steps in a flight, there should be not more than

one flight without a change in direction of at least 30. (See fig 4).

Landings

1.1.12 A landing should be provided at the top and bottom of every flight except that a

landing may not be necessary between a flight and a door if the total rise of the flight is

not more than 600 mm and the door slides or opens away from the steps. The landing

may include part of a floor. The width and going of the landing should be at least as greatas the smallest width of the stairway

1.1.13 Landings should be clear ofpermanent obstruction. A door opening onto a landing

should be so positioned thatthere will be a clear space of at least thefull width of the

flight between the doorswing and the flight (see fig 5 forexamples).

1.1.14 Landings should be level except that, where they are formed by the ground; they

may slope up to 1: 50 provided the ground is paved and textured.

Loft Conversions

1.1.15 Spiral stairways with goings less than shown in BS 5395 Part 2:1984 andalternating tread stairways would not normally be regarded as acceptable.


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However, they may be considered in the conversion of a loft where space is limited and

the stairway serves only accommodation which will be used infrequently and where the

accommodation includes not more than one habitable room. Alternating tread stairways

should have handrails on both sides and the treads should have slip resistant surfaces. The

goings and rises for the wider parts of the steps should conform to paragraphs 1.1.3 and

1.1.4.

Figure 4. LandingsFixed Ladders

1.1.16 A fixed ladder should have fixed handrails-on both sides. It should not be used as

primary access to a habitable room.

Handrails

1.1.17 A stairway should have a handrail on at least one side if it is less than 1000 mm

wide. It should have a handrail on both sides if it is wider. Handrails may not be

necessary beside the two bottom steps of a stairway. Handrails should be at a height of

between 840 mm and 1000 mm, measured vertically above the pitch line, and give firm

support. A handrail may form the top of the guarding if the height is suitable. The

handrail should be so constructed and fitted as to be capable of being readily gripped by

hand and safely used. Stairways which will habitually be used by elderly or physically

disabled people should ideally have handrails on both sides of the stairs not more than

900 mm apart so that both handrails may be gripped at the same time.

Guarding

1.1.18 Stairways should be guarded at the sides except that where the total rise of any

flight is no more than 600 mm guarding may not be essential. Suitable guarding would

include a wall, screen, railing or balustrade.

1.1.19 Guarding should be designed and built in such a way that it does not present

unacceptable risks of accidents in service. Guarding should be so constructed that a 100


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mm diameter sphere cannot pass through any openings in the guarding and that it will not

be readily climbable by children.

1.1.20 The heights of guarding recommended in BS 5395:1977 are set out in Table 2.The

guarding should be able to resist a horizontal force, at the height given in Table 2, of 0.36

kN for each meter of length if it guards a private stairway, or, 0.74 kN if it guards any

other stairway.

Figure 5. View showing steps on Storey Rod


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Figure 6. View of stair showing: Steps, Carriage, Glue Block, Rough Bracket

Figure 7. View of section through stairs

Figure 8. View of top newel post fixed to trimmer


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Figure 9. View of method for fixing handrail bolt

Figure 10. View of marking out a cut string

Figure 11. Closed string staircase, jointing of newel post to the string and handrailNote: Height of handrail 840mm to 1000mm.


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Figure 12. View of stairs showing the required headroom

Figure 13. View of closed string staircase:A. Joints of treads and risers.

B. Pitch board with margin template.

C. Tread and riser templates with wedge room added.


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Figure 14. View of open or cut string showing method of construction.

Figure 15. View of methods for jointing steps


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Figure 16. View showing a method for cramping up stairs


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Figure 17. Building regulation staircases (straight flights)


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Figure 18. Stair parts


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Figure 19. Templets


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Figure 20. Landing details


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Figure 21. Stair detail


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Self Assessment


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Index

C

Closed String Staircase ...................... ...................... .10

Construction ................... ..................... ................ 10Construction

Fixed Ladders .................... ...................... ............16

Landings ..................... ...................... ................... 15

Loft......................................................................15

Construction of Closed String Staircase ................... 10

Construction of Steps................................................14

Headroom............................................................14

F

Fixed Ladders ...................... ..................... ................ 16

Guarding..............................................................16

Handrails .............................................................16

G

Guarding...................................................................16

H

Handrails...................................................................16

Headroom .................... ...................... ...................... .14

L

Ladders ..................... ...................... ..................... .....11

Guidance............................................................. 11

Landings............... ...................... ..................... ......... 15

Length Of Flights..................................................... 15

Loft Conversions..... ...................... ...................... ..... 15

R

Ramps ...................................................................... 11

Rise, Going and Pitch......... ...................... ................ 13

S

Setting out Stairs ...................................................... 10

Stairs ........................................................................ 10

Closed String Staircase ....................................... 10

Settings Out ........................................................ 10

Straight Flight Of Stairs...................................... 10

Stairways

Length................................................................. 15Widths................ ...................... ...................... ..... 15

Stairways and Ladders ............................................. 11

Guidance............................................................. 11

Stairways and Ramps............................................... 11

Steps

Construction............... ..................... .................... 14

Straight Flight Of Stairs ........................................... 10

W

Widths Of Stairways ................................................ 15

Stairs Joinery

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