Helping to create a safe staircase through correct Stair Nosing specification.

Transcription

1 Helping to create a safe staircase through correct Stair Nosing specification. A guide to features of Stair Nosing design and how these are influenced by guidelines in current Building Regulations, British Standards and a BRE Information Paper that impact and contribute to the specification of a safe staircase in buildings with public, commercial and shared residential access.

2 Contents 1. Summary 2. The Regulations and their Background 3. Background to Stair Nosings 4. Stair Nosing Features: I. Dimensions II. Light Reflectance Values (LRV) III. Slip Resistance IV. Tread Cover V. Associated Tactile Approach Surfaces 5. Specification Solutions that Meet the Guidelines 6. Stair and Stair Nosing Terminology 7. Further Reading References Page 2 of 17

3 1. SUMMARY The Risk There has been much research undertaken into safety on stairs, since one of the many statistics established over the years is that over 300,000 patients a year on average visit hospital because of an accident on a staircase. This underlines how important it is that a staircase should be made as safe as possible. Stair Nosing Features Correctly specified and installed Stair Nosings are one of the principle factors necessary for the creation of a safe staircase. Certain features of Stair Nosing and stair design help to satisfy criteria that are set out in guidelines appearing in current Building Regulatory documents. An overview of these features is as follows: 1. Stair Nosing dimensions should be 50 to 65 mm on the tread and 30 to 55 mm on the riser 2. The colour of the Stair Nosing should have a Light Reflectance Value of 30 points difference to the surrounding floor covering (i.e. on the staircase) 3. The slip resistance of the tread material (in both wet and dry conditions) should have a laboratory tested PTV reading of at least 36 and/or a micro roughness reading of 20µ 4. The Stair Nosing tread material should cover the whole of the upper surface of the Stair Nosing right up to and over the front edge 5. At the upper and lower approaches to stairways (particularly in external locations) there should be a corduroy tactile surface Regulatory Guidelines Guidelines covering these aspects/topics appear in the following Documents: I. Building Regulation Document K Protection from Falling, Collision and Impact II. Building Regulation Document M- Access to and Use of Buildings III. BS5395.1:2010 Stairs Ladders and Walkways IV. BS8300:2009+A1:2010 Lighting and Stepped Access and Slip Resistance. V. BS9266:2013 Design of Accessible and Adaptable General Needs Housing VI. Building Research Information Paper IP15/03: Proprietary Nosings for Non-domestic Stairs As is stated, these are guidelines, and there are other important criteria which also contribute to the creation of a safe stair. These include step dimensions and the presence and positioning of hand rails, good lighting and regular maintenance and cleaning. Page 3 of 17

4 Main Feature However, with respect to Stair Nosings, these guidelines set out to cover one safety feature of a staircase namely that All nosings are made apparent by means of a permanently contrasting material.on both the tread and the riser portion of the step nose (BR Document M). This criteria (along with the slip resistance and full cover of the tread material) ensures the creation of what is termed a ladder effect when the stairway is viewed from the top or bottom. This helps to clearly identify each step, which is of particular assistance to the partially sighted and thereby an objective of the Equality Act (2010) which incorporates the Building Regulation Documents, British Standards and BRE information Paper referred to in this document. Page 4 of 17

5 2. THE REGULATIONS AND THEIR BACKGROUND The Regulations There are six documents which give guidance for the design of stairs and associated Stair Nosings in buildings with public, commercial and shared residential access. They are: I. Building Regulation Document K Protection from Falling, Collision and Impact II. Building Regulation Document M- Access to and Use of Buildings III. BS5395.1:2010 Stairs Ladders and Walkways IV. BS8300:2009+A1:2010 Lighting and Stepped Access and Slip Resistance. V. BS9266:2013 Design of Accessible and Adaptable General Needs Housing VI. Building Research Information Paper IP15/03: Proprietary Nosings for Non-domestic Stairs Building Regulations (BR): are statutory instruments that seek to ensure that the policies set out in the relevant legislation are carried out. British Standards (BS): are the standards produced by BSI Group which is incorporated under a Royal Charter (and which is formally designated as the National Standards Body (NSB) for the UK). Building Research Establishment (BRE) Information Papers: These summarise recent BRE research findings, and give advice on how to apply this information in practice. Principle Requirement An overriding statement which encapsulates the basis for the content of all the above comes from current Building Regulations 2010 Approved Document K 2013 edition (Requirement K1: pp3) where it states that it is a requirement that: Stairs, ladders and ramps shall be so designed constructed and installed as to be safe for people moving between different levels in or about the building." Page 5 of 17

6 Stair Nosing Features Specific sections of the documents above expand on the detail as to how a Stair Nosing can help (stairs) achieve this requirement. There are also five features which are applicable to Stair Nosing design and appearance and it is these that need to be considered when specifying a Stair Nosing installation. The chart that follows names these features and indicates the document in which the respective detail appears. A complete bibliography, indicating all relevant publications can be found on page 17. Document/Paper Dimensions Light Reflectance Slip Resistance Tread Cover Tactiles Value (LRV) Feature BR Document K x x BR Document M x x x x BS5395.1:2010 BS8300:2009+A1:2010 x x x x BS9266:2013 x x BR IP 15/03 x x The following pages explain in detail what these regulations require with respect to each aspect. Solutions that help meet the guidelines are then indicated in section 6 to enable the specification of a safe and good practice Stair Nosing application that is also fit for purpose. Background to the Regulations and the Guidelines affecting the features of Stair Nosings Stair Nosings have always been considered by specifiers and contractors to be a safety product for stairs with the added benefit of providing a protective edge for floor coverings. For many years there was little or no guidance for any criteria that the products should meet in order to be fit for purpose. That is until the late 1990 s, when under the mantel of the Disabled Discrimination Act (DDA) the Joint Mobility Unit (JMU) - a sub division within the Royal National Institute for the Blind (RNIB)- incorporated guidelines for Stair Nosings designs that would make it safer and easier for the partially sighted when ascending or descending stairs in buildings with commercial, public or shared residential access. At this time the JMU guidelines translated into Stair Nosing design features that included specific shapes, dimensions and colour differences with stair floor coverings. Throughout the 2000 s these guidelines were interpreted in different ways by all involved. Manufacturers, contractors, and specifiers alike found it difficult to agree on what was needed or wanted. Consequently, the application of the guidelines was at best minimal, and therefore the use of traditional Stair Nosings and materials continued. Page 6 of 17

7 In 2010 the principle elements contained within the DDA were absorbed into the Equality Act, which became a legal entity representing the interests of any disadvantaged group. Along with this Act came improved definitions of the requirements for Stair Nosings; these are now contained within current Building Regulations, British Standards and a BRE Information Paper. This improved clarity makes the achievement of good practice as far as the design and application of Stair Nosings is concerned much more easy to understand. The aim of this document is to set out the re-stated guidelines for Stair Nosings, such that the right profile with the correct colour definition can be specified for any given stair within buildings with public, commercial and shared residential access. Page 7 of 17

8 3. BACKGROUND TO STAIR NOSINGS (If you re interested!) How did Stair Nosings become a standard feature on stairs? The origins of the product known as a Stair Nosing (or stair edge), a protective safety edge on the nose of steps, is not important enough to be officially recorded. However, a clue to its known history is in one of its key features namely safety. In particular slip resistance, since it was from the company of Ferodo that specialised in the manufacture of friction materials, that Stair Nosings first appeared during the 1950 s and it s not possible to be more precise than that! Based in Chapel-en-le-Frith in Derbyshire, as friction product specialists, Ferodo was the world s most renowned producer of braking materials for anything that moved with rotating parts; carts, cars, trucks, trains, planes (when on the ground!) industrial equipment etc. Initially all the friction materials produced were made of woven asbestos impregnated with resins; well proven to dissipate the heat generated by braking. Asbestos continued to be the base material for brake linings and pads until Health and Safety caught up with the serious risks to health posed by this material. An early Ferodo product development programme came up with another use for the woven asbestos cloth. Strips cut to step widths and put around the nose of steps considerably reduced the risk of slips on stairs, and then subsequently to stop fraying at the edges, an aluminium carrier soon followed. The Stair Nosing as it is now known was born. Asbestos has long since been removed from the treads used in Stair Nosings; pvc, rubber based and silicon carbide or carborundum materials now provide the slip resistant surface needed to help the products attain one feature of their safety function. Colour contrast and durability are other performance functions of these products since their installation also provides a visual aid to the steps position and also protects floor coverings used on step treads from unnecessary wear. Aluminium is still a favoured carrier material, although PVCu with its colour options is an alternative that is becoming more and more specified. Despite the shortcomings of the original treads, Ferodo nevertheless introduced a product that has been proven to enhance the safety of stairs around the world for over 60 years, as British trained specifiers have become involved in construction projects internationally. The brand of Ferodo Stair Nosings is no more other companies have taken over the baton, and through product design have developed profiles that accommodate all modern step shapes, sizes and flooring coverings. The features that Stair Nosings offer to the finish of stairs have now become embodied as guidelines in current Building Regulations, British Standards and a BR paper. This document has been compiled to identify the specific features of Stair Nosings that can help specifiers, contractors and users meet these guidelines when completing a stair design, construction or installation of a staircase that has access to commercial. public or shared residential foot traffic. Page 8 of 17

9 4. STAIR NOSING FEATURES There are five; I Dimensions II Colour Iii Slip Resistance of Tread material IV Tread Surface V Tactile Surfaces I. Dimensions Feature summary A Stair Nosing should have dimensions of between 50mm and 65mm across the upper tread surface and 30-55mm on the riser. (Earlier these dimensions were stipulated only as being 55mm x 55mm respectively). They are intended to ensure that a good step definition can be achieved when a suitable colour contrasting with the floor covering material (see next topic) is selected. The summary above is a compilation of the guidance sometimes a little confusing contained within the following documents: Building Regulation 2010 (Approved Document K 2013 edition) Section K1.7(a) For buildings other than dwellings - use a material that will contrast visually, a minimum of 55mm wide, on both the tread and the riser. Section K1.10(a) For common access areas in buildings that contain flats use a material 50mm to 65mm wide on the tread and 30mm to 55mm on the riser Building Regulation 2010 (Approved Document M1/M edition) Section 1:33 All nosings are made apparent by means of a permanently contrasting material 55mm wide on both the tread and the riser. BS8300:2009+A1:2010 Section p26 The material should be 50mm to 65mm wide on the tread and 30 to 55mm on the riser BS9266: Sections 6.8 p8 and 8.2 p16 The material should be 50 mm to 65 mm wide on the tread and 30 mm to 55 mm on the riser, and should contrast visually with the remainder of the tread and riser. In the early days of the DDA the guidance was quite restrictive in as much that the dimensions required were declared as being specifically 55mm on both the tread and the riser. This resulted in some rather cumbersome Stair Nosing designs that have never been popular with specifiers. More recently and with the advent of the Page 9 of 17

10 Equality Act the guidance has allowed specifiers a little more latitude and the 50 to 65mm and 30 to 55mm brackets for Stair Nosing tread and riser dimensions respectively ensure that good design can also go hand in hand with satisfying the regulatory guidance for a safe stair. This apparent difference in the regulatory guidelines can be reconciled by specifiers and contractors since both sets of guidance are correct. As has been stated, the principle requirement is that the nose of a step is clearly defined and a proprietary Stair nosing within any of these dimensions can achieve this. Step dimensions and the degree of foot traffic can also influence the choice of Stair Nosing to be installed. The principle function of a Stair Nosing in this regard is to provide the right dimensions for the visual contrast needed to make a clear definition of a steps nose. II: Colour: Light Reflectance Value (LRV) Feature Summary The Light Reflectance Value (LRV) of a colour is a measure* of the amount of visible and usable light that reflects from (or absorbs into) a given coloured (painted) surface. Simply put, LRV measures the percentage of light a (paint) colour reflects. LRV is measured on a scale that ranges from 0 (absolute black, absorbing all light) to 100 percent (pure white, reflecting all light). *Total quantity of visible light reflected by a surface at all wavelengths and directions when illuminated by a light source - BS 8300:2009 In the context of the creation of a safe stair this is perhaps the main Stair Nosing feature, since it is the colour difference between the Stair Nosing and the stair floorcovering that creates (BS 9266:2013): a permanently contrasting continuous material for the full width of the stair on both the tread and the riser, to help people with a visual impairment appreciate the extent of the stair and identify individual treads. In the early days in the establishment of the DDA, the Joint Mobility Unit (JMU), a division within the RNIB, worked in conjunction with Reading University on Project Rainbow, which was set up to establish a system of colour measurement; the aim being to give a value to any given colour. The outcome was the grading of colours by the degree of light reflectance from a given surface, and a scale was established where black was 0 and white 100 different colours from different surfaces were then graded between these two parameters. The JMU then undertook their own empirical trials and concluded that a colour (Light Reflectance Value LRV) difference of 30 points gave a definable contrast that could be differentiated by the visually impaired. Taking this a stage further, and applying it to the difference of LRV between the Stair Nosings and the surrounding floor covering on a staircase, a ladder effect is created which is key to the establishment of a contrast on the steps that makes a staircase safe. Page 10 of 17

11 References to the guidelines for LRVs can be found in the following documents: I. Building Regulation 2010 (Approved Document K 2013 edition) p6 section 1.10 and p51 Appendix A II. Building Regulation 2010 (Approved Document M 2013 amended) Introduction. pp15 &16 III. BS8300:2009+A1:2010 Annex B1 p183 IV. BS9266:2013 Section 8.5 p16 Couple this requirement for a colour difference between a Stair Nosing and the floor covering on a stairway with the Stair Nosing dimensions in Feature 1 and the essential requirements for a Stair Nosing that will satisfy regulatory guidelines are established. The Ladder Effect is created by the contrasting band of colour provided by the Stair Nosings if the LRV difference with the floorcovering is 30 points. When viewed from the top or bottom of the stairs the impression should be of clearly identified stepping positions as if they were the rungs of a ladder. This is of particular benefit to the partially sighted, and along with correctly dimensioned steps and well positioned handrails contribute to making a staircase safe for all users. III: Slip Resistance of Tread Material Feature Summary The upper surface of a Stair Nosing is designated the tread, as is the horizontal section of each step. On a Stair Nosing the tread needs to offer a slip resistant surface that will help prevent the incidence of mishaps when footfall is ascending or descending a stair. The guidance for the slip resistance of Stair Nosing tread material is very much linked to that of the floorcovering on the stair case. The following Documents make reference to the slip resistance of Stair Nosing tread material and give guidelines for their performance in this regard: I. Building Regulation (Document M) reference refers to BS8300 (see below) II. BS5395.1:2010 Section 10.6 p14 III. BS8300:2009+A1:2010 Section 9.5 p26 and Annex E.5 p196 IV. BRE IP15/03 (13) In both cases the guidance for the slip resistance of the Stair Nosing tread is that the material used should have a Rubber Boot 95 Pendulum Test Value (PTV) of at least 36 in both dry and wet conditions. The Pendulum test method is a standard system for the measurement of the resistance of floor covering materials. The practical problem however is that once a Stair Nosing is installed, due to the restricted width of a step s tread, there is insufficient room for the pendulum to be swung on site. Therefore, the guideline measurement can only be achieved in factory conditions prior to any installation, and thus the measurement of used tread material on site is not possible. Page 11 of 17

12 (A PTV measurement of the tread material on the top most step of a stair case can be undertaken, and this may give an indication of the tread material on the other Stair Nosings on the flight, but it is no more than that an indication). For a used or on-site measurement of Stair Nosing tread slip resistance an additional means of measurement is with a surface roughness micrometre. The Health and Safety Executive (HSE) has established guidelines in its Slips Assessment Tool (SAT) which is a freely downloadable computer software package that allows an operator to assess the slip potential of pedestrian (walkway) surfaces. It indicates that if a material has a micro roughness reading greater than 20 µm, then it can be classified as being of Low Slip Risk. Slip Potential Rz Value 1 PT Value 1 High Slip Potential below 10 µm 0-24 Moderate Slip Potential Mm Low Slip Potential 20+ Mm 36+ (minimum requirement) 1 RZV=Surface Roughness Values and PTV=Pendulum Text Values As a consequence of the limitations inherent in the opportunity to achieve reliable on-site slip resistance measurements of Stair Nosing tread material, the current best practice guidance is a combination of the two methods. It is recommended that specifiers, contractors and end users look to install Stair Nosings with tread material that has been independently laboratory tested to have a PTV greater than 36 and similarly a micro roughness reading of more than 20 µm both in wet and dry conditions. It is then possible (if necessary) to use a micro roughness metre on site to re- measure the µ value and comparisons can be made to give an indication of any changes over time. Due to the variability of site conditions however it should be stressed that this is very much only an indication. The following extract from BS8300:2009+A1:2010 Annex E.5 p196 sums up the position: Where slip resistance is required for nosings and treads, the slip resistance needs to be equivalent to that expected for level surfaces. A PTV greater than 36 is considered to be suitable, as pushing and turning are unlikely on stairs. On existing nosings, the slip resistance of step nosings are generally expressed by their Rz roughness value as PTV is difficult to measure. In such cases a roughness Rz value of 20μm is recommended.. Page 12 of 17

13 IV: Tread Surface Feature Summary Traditionally the Stair Nosing tread material has been contained within a shallow channel on the upper surface of the Stair Nosing carrier the carrier usually being made from aluminium, PVCu or in a limited number of cases, cast iron, steel, brass or bronze. More recently (October That is Mike Roys' paper "IP5") however work undertaken at the Building Research Establishment has concluded that the tread material should extend right across the upper surface of the Stair Nosing. This recommendation is contained within BRE IP 15/03 which covers many aspects of stair design with respect to safety. It indicates that, particularly in descent, a person s foot fall will usually impact at an angle on the very front of the nose (edge) of a step. The shorter the going of the tread the more likely this is to occur. As a consequence, the improving guidance that comes from the work undertaken at BRE identifies that the most practical and safest format for a Stair Nosing tread material is for it to cover the whole of the upper surface of the Stair Nosing carrier right up to and over the front edge. This ensures that footfall, particularly in descent, is onto a slip resistant surface. The importance of this is heightened when the tread going is at the shorter end of the recommended design and construction dimensions. The relevant statement in BRE IP15/03 (p6) is: Slip-resistant nosing: The risk of slipping can be reduced if the proprietary nosing incorporates a material that has slip resistant properties at the point where contact is likely to be made.. the slip resistant material must continue to the very (front) edge of the tread. Page 13 of 17

14 V: Tactile Surfaces Feature Summary In addition to the guidelines for the steps on staircases and their respective Stair Nosings there are also recommendations for the surfaces on the approaches to stairways namely there should be a corduroy tactile surface at the top and bottom of flights of stairs. The purpose of these surfaces is to provide the partially sighted with a specific warning of the presence of a change in level by means of steps. These recommendations cover the installation of a tactile surface with certain prescribed dimensions at the approaches to a stairway. The guidelines can be found in: Building Regulation Document M Section 1.33 c and d p21 & p22 BS8300:2009+A1:2010 Section 3.10, Section p27 and Fig 9 p28 BS9266:2013 Section p9 and Fig 2 p10 In the case of the stairway approaches the requirement is for a corduroy tactile surface, as opposed to the blister variety found for example at crossing points on pavements and the edge of railway station platforms. As can be seen the recommendations for the dimensions and positioning of these surfaces are quite specific, and note should be made that they are not placed on half landings* only at the top and bottom of a flight. As experience through use and application has been gained, although the BR and BS guidelines are for stairways in general, the practical installation of these corduroy tactile surfaces has been mainly for external applications. A choice to include an internal installation should be determined by taking into account the safety considerations of the site. The principle decision making process being to ensure a stairway is safe for the volume and type of foot traffic expected. *The exception being when there is an entrance/exit to/from the half landing. Page 14 of 17

15 5. SPECIFICATION SOLUTION THAT MEETS THE GUIDELINES The following selection process can be used to select a Stair Nosing that meets the regulatory guidelines. 1. Establish thickness of floor covering on the stair this determines the Stair Nosing gauge or thickness needed. 2. Identify the step nose profile straight or rake back. 3. Establish the LRV of the chosen floor covering and select a complementary colour for the tread of the Stair Nosing that is 30 LRV points different from the floor covering. 4. Choose a proprietary Stair Nosing with: I. The right gauge for the floor covering II. The correct profile shape for the step nose and dimensions of 55-65mm across the tread and mm on the riser. (55mm x 55mm is also acceptable) III. Tread material that has a suitable LRV difference of 30 points IV. Tread material across the whole surface of the Stair Nosing V. (Strictly speaking the colour band should be included on the riser as well, in which case the best solution is to specify a Stair Nosing carrier produced in PVCu in a colour that matches the chosen tread material colour. Traditional aluminium Stair Nosing carriers are acceptable so long as they do not reflect bright light in a manner that creates a glare satin finished options are available to minimise this risk.) Note: Wooden (and some old stone) stair cases have rounded (bull-nose) step nose profiles. These can present a trip hazard to the partially sighted, so are not recommended. However, in a refurbishment situation they cannot always be avoided. In such cases it is recommended that attention be given to ensuring that a good band of contrasting colour ( All nosings are made apparent by means of a permanently contrasting material ) is achieved across the nose of each step, thus producing a good ladder effect that will enhance the safety of the stairway. Look out for the Best Practice Building Regs Solutions Logo in the Quantum flooring pocket guide and specification guide for Stair Nosings which meet all the guidelines if specified correctly. Page 15 of 17

16 6. TERMINOLOGY LRV: In architecture, light reflectance value (LRV), is a measure of visible and usable light that is reflected from a surface when illuminated by a light source. Ladder Effect: Creating a visible contrast between the step and the nose of the step. Slip Resistance Testing: Floor slip resistance testing is the science of measuring the coefficient of friction (or resistance to slip accidents) of flooring surfaces, either in a laboratory (before or after installation) or on floors in situ. DDA: The DDA is a civil rights law. Other countries use constitutional, social rights or criminal law to make similar provisions. The Equality and Human Rights Commission combats discrimination. Equivalent legislation exists in Northern Ireland, which is enforced by the Northern Ireland Equality Commission. Stair Winders: Winders are steps that are narrower on one side than the other. They are used to change the direction of the stairs without landings. A series of winders form a circular or spiral stairway. When three steps are used to turn a 90 corner, the middle step is called a kite winder as a kite-shaped quadrilateral. Page 16 of 17

17 7. FURTHER READING REFERENCES BS (2010) Stairs part 1: Code of practice for the design of stairs with straight flights and winders. BS8300:2009+A1:2010. Design of Buildings and their approaches to meet the needs of disabled people. Code of Practice. BS8493:2008+A1:2010. Light Reflectance Value - method of test. BS9266:2013 Design of Accessible and Adaptable General Needs Housing. Building Regulation Document M (2013)- Access to and use of Buildings. CIRIA C722 (?) Safer Stairs in Public Places Assessment of Existing Stairs. Alderson A (2010) Stairs, ramps and escalators RIBA publication in conjunction with Centre for Accessible Environment (CAE). Cook G et al (2010). The Colour Light and Contrast Manual - designing and managing inclusive building environments. Edwards Dr.N et al (?). Steps to Safer Stairs. Community of Health Research Unit University of Ottowa. Health and Safety Executive (HSE) Assessing the slip resistance of flooring - a technical information sheet. Includes details of HSE/HSL PC based software Slips Assessment Tool (SAT). Nagata H (2006). Evaluation of Safety Dimensions of Stairway. International Ergonomics Association Paper Pauls J ( ). Introduction to Stairway Safety. Roys M (2012). Building Research Establishment (BRE) Information Paper IP 15/03. Proprietary Nosings for nondomestic stairs. Scott A (2005). Falls on Stairways - Literature Review. Health and Safety Laboratory (HSL) Buxton Derbyshire HSL document 2005/10. Thorpe S et al (2012). Investigating Stair Accidents. Proceedings of ISOES Conference pp Workplace Health, Safety and Welfare Regulations (1992) and Approved Code of Practice and Guidance. ( Publication - a short guide for managers. Regulation 8 - Lighting / Regulation 9 - Cleanliness and waste materials / Regulation 12 - Condition of floors and traffic routes / Regulation 17 - Organisation of traffic routes Page 17 of 17