Nov 152011
 

Safety is Paramount when it comes to Stairways-Part M

Stairs-PartM

It stands to reason that stairways must be safe. If stairs are too steep, and they don’t have railings, or if screens and balustrades are not strong and secure, people may fall with disastrous consequences.

What the National Building Regulations say about Stairs and Stairways

“Any stairway, including any wall, screen, railing or balustrade to such stairway, shall:

(a) be capable of safely sustaining any actions which can reasonably be expected to occur and in such a manner that any local damage (including cracking) or deformation do not compromise its functioning;

(b) permit safe movement of persons from floor to floor; and

(c) have dimensions appropriate to its use.”

What this means is that stairways, in addition to all the elements relating to them, must be properly designed. This takes us back to Part B of the NBR, which deals with structural design.

Like everything else, stairways must be designed to provide the strength, stability, serviceability and durability required for use. It is imperative that they are built so that any accidental overload won’t cause the stairway to collapse. It is also vital to takes steps to ensure that people won’t fall off the structure. If the sides of the stairs don’t have railings or screens this CAN happen – and it does (sadly) happen.

In addition to these general requirements, there are fire requirements that must be adhered to. These are outlined in Part T of SANS 10400 – Fire Protection, but when it comes to houses, those that are relevant mainly relate to basics (including the materials used to build your home). For instance you don’t have to have fire escapes, exit doors, escape routes, and that kind of thing.

SANS 10400 Stairways – Part M

As always, the South African National Standards give a good rundown on how we should build to ensure that we “satisfy” the legislation. The most recent Standard was published in April 2011; and it contains new guidelines that relate to both masonry stairways and timber stairways.

You will find Part M of the legislation towards the end of Standard, on Page 11.

It should be read in conjunction with several other Standards, including SANS 2001-CC1, -CC2, and -CM1 that deal with structural concrete works, minor concrete works and masonry walling; SANS 1460, Laminated timber (glulam); and SANS 1783-2, that deals with stress-graded structural timber and timber for frame wall construction; as well as several other parts of SANS 10400, specifically Part A (general principles), Part B (structural design), Part K (walls), Part S (facilities for people with disabilities), and Part T (fire protection). This is important because, for instance:

  • Part S reduces the rise of the step (as indicated in this part), increases the width of stairways and the length of landings. It also has a requirement that solid risers should be used where stairs overlap the next lower tread, and another that specifies the need for handrails on both sides of the stairway.
  • Part T increases the standard width of stairways as indicated in this part, disallows the use of spiral stairways, and requires solid risers for all buildings except those defined in Part A as D4 (a plant room that contains mechanical or electrical services that are necessary for the running of a building, and are usually left unattended).

Requirements of this particular Standard that relate to dimensions specify that:

  • there must be sufficient headroom above any stairway: at least 2,1 m measured vertically from the pitch line of the staircase (see drawing below)

    stairways

    Minimum headroom allowed on stairways

  • stairs need to be wide enough for safe use, usually not less than 750 mm (see drawing below)
  • the going (depth of the tread) and width of treads must be at least 250 mm (see drawing below)

    stairways

    Allowable minimum dimensions of treads and risers

  • treads of stairways that do not have solid risers must overlap the next tread by at least 25 mm (see drawing above)
  • landings serving two flights in a straight line need to be at least 900 mm long and at least as wide as the flight of stairs
  • there shouldn’t be a vertical rise that is greater than 3 m between landings
  • single step risers shouldn’t be more than 200 mm
  • doors cannot open onto stairways unless it’s onto a landing – and the landing then needs to be at least the width of the door (which must not obstruct people using the stairs)

Sometimes the dimensions of risers and going of treads vary in a flight of stairs. This variation should not be more than 6 mm. Further, dimensions of each individual step can be checked for safety by adding the dimension of the going to 2 x the height of the riser. This should be at least 570 mm and no more than 650 mm.

Tapered treads and winders (which are are steps that are narrower on one side than the other and used to change direction of the stairs without landings) are most common in spiral stairways. If they don’t form part of a spiral staircase, they must be designed to comply with the minimum tread and riser dimensions shown in the drawing above, and have a minimum going of 125 mm. The angle between successive risers (measured horizontally) must be constant (see drawing below).

stairways

To check the variation in going between tapered treads, measure each tread at the same distance from the narrow end

Stairways that incorporate winders – defined by the SANS as a “tapered tread that has a going of at least 50 mm and which is used in conjunction with non-tapered treads in a single flight” –  are permitted in our homes as long as there are no more than three of them, and the winder may not turn through more than 90 degrees.

Spiral stairways are defined as a “succession of tapered treads forming a curved stairway which extends as a single flight from one floor or landing to another”. These must be no wider than 800 mm and may not be used as an emergency route. There are also restrictions in terms of certain buildings where they may not be used, including theatres and other entertainment venues, schools, sports facilities, places of worship, exhibition bass, jails, hospitals and health care facilities, offices, hotels, dormitories and hospitality venues.

Prevention Against Falling

It should be common sense, but people don’t always see it that way, because stairs don’t always LOOK good with railings!

Essentially what SANS tell us is that:

If a flight of stairs is more than three risers high, it could be dangerous, especially if toddlers and old people use it. This is why it is essential to have some sort of protection to prevent falling.

This can be in the form of:

  • a secure wall
  • a screen of some sort
  • railings or a balustrade – all of which should be at least 1 m high

Other issues include “openings”. If a child can fall through a gap in the railings, or if someone falls and their leg or foot gets stuck in the gap, it could end up really badly. The opening specification is similar to that which relates to swimming pool fencing: it shouldn’t allow anything with more than a 100 mm diameter to pass through it.

Handrails are also an important element. If a flight of steps continues for more than about five risers, there should be a handrail of some sort. And any sort of handrail MUST be securely fixed to the wall, screen, railing, balustrade or whatever! In some instances, for example when the stairs are wide (more than 1,1 m), it might be necessary to have a railing on either side.

If a screen is made of glass, it is vital that the glass used complies with the relevant SANS.

Timber Stairways

There are several clauses that relate specifically to timber stairs in SANS 10400 Part M (Edition 3, 2011). This section was previously not covered in the “deemed to satisfy” regulations.

Stringer Beams

Stringer beams support treads, and where these are not be wider than 1,2 m in double- and single-storey domestic residences and dwelling houses, they should be at least 48 mm x 225 mm. Grade 5 timber should be used and it should not be excessively warped.

Timber Treads

These must be at least 36 mm thick. Since timber stairways are designed in different ways, the options are that they may be:

  • built into masonry walls with a minimum end bearing of 90 mm
  • supported on a steel angle cleat that has minimum dimensions of 50 mm x 50 mm x 4 mm
  • bolted to a wall with two masonry anchors per clear according to the manufacturer’s instructions

If anchors are used and embedded into a Grade 20 concrete (which will be 20 MPa), these anchors must have  “a safe working load in sheer of not less than 1,25 kN, certified by the manufacturer”.

Materials Used for Timber Steps

Building Materials and Tests in general are covered in Part A of the National Building Regulations. In terms of timber, it should be treated against termites and wood borer as well as protected against fungal decay in terms of SANS 10005. For consumers, the important thing to look for is the product certification mark of a body that has been certified by the SA National Accreditation System.

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  133 Responses to “Stairways”

Comments (131) Pingbacks (2)
  1. How can one ensure that the staircase installer is accredited.

    • I am not aware of any form of accreditation as such. All staircases must comply with the building regulations and various relevant SANS. They should also be designed by a competent person – see here to learn more about competency.
      If someone is building the stairs for you, you can ask for proof of qualifications as well as specs on the materials to be used. They would also need approved plans. If you are installing a precast staircase, you can ask for proof of the qualification of the designer and of the materials used in terms of the relevant SANS. It would depend what type of staircase it is and the specific materials used. e.g. concrete, brick, timber, steel.

  2. Hi, I am dealing with an insurance claim where a lady fell down on a flight of wooden steps during heavy rain. Obviously the steps are outdoors. At the time of her fall there were no anti-slip strips on the steps, but they have been installed now. I didn’t measure, but the risers seem to be less than 20cm and I estimate the treads are about 25cm wide. There are seemingly adequate balustrades, as the woman grabbed onto them and didn’t fall all the way down. From the deck to ground level is approximately 3m (no landing), but may be slightly more. (I didn’t measure anything at the time I was there, as the steps seemed solid to me and the question only came up afterwards about the regulations being adhered to). Can I send you photos to get your general impression? Personally, I suspect that the only issue may have been the lack of anti-slip strips, but I’d like any comment please.

    • Mark the minimum dimensions for steps are all given above, but as you say, they look perfectly reasonable. In terms of the SABS deemed-to-satisfy rules, the rise should be no more than 20 cm (200 mm) and the treads should be no less than 25 cm (250 mm).
      The pictures you sent me of the steps show that they do not have solid risers – in which case each tread needs to overlap the next lower tread by no less than 25 mm – and it looks as if they do.
      There is nothing in the NBR that I can find that mentions “anti-slip strips”, or even safe materials. Obviously if wooden steps were varnished, they’d become very slippery in wet weather. These look quite worn, but not to the extent of being hazardous in any way.
      The Act itself states:
      “Any stairway, including any wall, screen, railing or balustrade to such stairway, shall:
      (a) be capable of safely sustaining any actions which can reasonably be expected to occur and in such a manner that any local damage (including cracking) or deformation do not compromise its functioning;
      (b) permit safe movement of persons from floor to floor; and (c) have dimensions appropriate to its use.”
      I am not convinced that not having an anti-slip strip was in contravention of this law. i.e. It appears that the regulations WERE adhered to. In fact, having taken photographs of thousands of steps over time, we have NEVER seen wooden steps with anti-slip strips! And in all the research I have done for garden structures, I have never seen this recommended either – though I will recommend the idea in future.
      It seems to me that this was an unfortunate accident, and that the owner has now responsibly installed anti-slip strips to prevent something similar happening again.

  3. Hi,

    I have bought a stand in an Estate, The plan that I chose is double story house but now the staircase are a a set of 14 steps straight up (steep) design. They still building the house but the staircase has already been fitted, when i went to view the house i went up the stairs and i noticed that the tread fit my 3/4 shoe size & they are not even the same size all of them. when i go down the steps it feels like im going to fall on my face, i had to literally go down with my side to be more cautious. It worries me cause i just heard that several people who has the same design complained but they said nothing could be done because there’s no space to do them otherwise so other ppl left it as it is & i just found out that soon to be my neighbour fell down on his steps & he was taken to hospital so this worries me especially having a small baby that this will be my living nightmare cause they also just told me that nothing can be done but i still need to take measurements of the steps to prove my case. What are my options here? what should i do to make them redo my staircase? Is there a chance of me winning this case? Thank you, I will wait for the response.

    • Lack of space is not an acceptable excuse for not building according to the National Building Regulations. There are three courses of action you should take.
      1. The law states that builders must be registered with the NHBRC. Since the building is in progress, notify the NHBRC immediately. If it turns out that the builders are not registered, then they are building illegally.
      2. Call in the building inspector and report the problem. The local council has the authority to insist that the stairs are demolished and rebuilt.
      3. Withhold payment until the situation is rectified. If you have a bond and the bank is making payments, alert them to the problem immediately.

  4. Must steps on a tiled staircase be level or can they be at a severe slant ? We recently had a staircase retiled in our office complex and the tiler was told to lay tiles on steps and landing at a severe slant, apparently to assist rain water to flow off quicker.

    • The risers can slant, but the part that you stand on (the tread) MUST be absolutely flat. If this is an outdoor staircase, there should be drainage on either side of the staircase to allow for run-off of rain water. If the treads slope they will be horrendously dangerous when wet!

  5. Hi

    The staircase in question is already built. I see that the risers are to be 200MM in height at the most.
    The risers on this staircase are anywhere between 221MM and 250MM. They are all different heights. Is this staircase a problem and will the council occupancy going to be affected by this. Does it need to be corrected according to the regulations before an inspection.

    Thanks,

    • Technically Gordon, if the stairs have not been built according to plan, the council has every right to demand that they are fixed before they give you an occupancy certificate.

  6. May there be any pot plants on the stairway – floor to floor

    • There is no building regulation against having pot plants on a stairway, but the health and safety regulations might come into play if the stairway is open to the public. The Occupational Health and Safety Act specifies how workplaces and public places must be kept safe.

  7. Hi, I wan’t to find out what the fire prevention regulations is on the paint of inside steel stairs of a building that is used as a fire escape. Is there a specific paint that needs to be used that is fire retardant and can you maybe send me the regulation if so?

    • Arno the regulations are really not that prescriptive. Manufacturers’ specifications should state that the product is SABS approved and if it is a fire retardant, it should state this as well. I suggest you call the SABS and/or a couple of major paint manufacturers. You might also contact your local fire department.

  8. Hi,
    Did the regulation on steel stairs change?

    1. Landing out the door min 1.5×1.2. Unless the door is see through.
    2. a flight of stairs should not be more than 3m with out a landing inbetween.
    3. In between flights should nou be closed and not lipped up at the bottom and down at the top.

    Please advise.

    Louis

    • Louis, As far as I know there is no specific standard for steel stairs – and the NBR do not differentiate between materials used to build stairs.
      I think the landing should be at least the width of the door – so it could be less than your dimensions.
      Since you specialize in steelwork (I presume from the name), I am sure you know a lot more about the subject than I do!

  9. I would like to know what the legal specification is for the measurement between infills of a balustrade and from a wall to a balustrade. What is the legal space allowed?
    Thank you

    • As far as I know, in terms of the NBR, railings and balustrades need to be at least 1 m high, and should not have openings any greater than 100 mm diameter. Other than that I don’t think there are specific requirements.
      The NHBRC manual I have states in its guidelines that freestanding balustrade walls should have a thickness of not less than the height of the wall above the base divided by a measurement based on the units used to build the wall. e.g. 5 mm for a solid unit (no dpc). It also says that if the balustrades have returns or are fixed to columns at centres not more than 3,5 m, the thickness must be 110 mm for solid units and 140 mm for hollow units. Returns must continue for at least 0,75 m from the outside face of the walls.
      But remember that these are recommendations and any “competent person”, e.g. an architect, will be able to design the balustrade taking all elements of the structure into account.

      • Hi,
        I read your comments on the safety aspects of balustrades, cant seem to find any government regulation, not SABS, NBR, NHBRC etc..

        As far as I know, in terms of the NBR, railings and balustrades need to be at least 1 m high, and should not have openings any greater than 100 mm diameter. Other than that I don’t think there are specific requirements.

        My questions is, This basic requirement has been around for some time now, As far as i am concerned is it not for the architect to design and spec? which in turn is a guild only but not a industry standard?

        I have never seen a balustrade which conforms to your specific requirements of 100 mm between openings ? All balustrade manufacturers cant work according to a guild! surly there should be a set standard in place, No compromise on cost?

        • Graham these are not our requirements – these are the requirements of SANS 10400 Part M, Stairways (the deemed to satisfy rules for the NBR). And we you talk of “a guild” I presume you mean guidelines.

  10. What about a patio? We have one but the drop between that and the ground is just over 40cm or so.. It doesn’t feel safe as a step height with no railings. What governs this?

    • The National Building Regulations say that step risers should not be steeper than 200 mm. So you should have a step between the patio and the ground (because at the moment it sounds as if you have to step up or down 400 mm). It doesn’t sound as if railings are an issue.

      • Thanks for the response.
        Yes I currently have to step up 42cm to get onto the patio.
        I think I’ll see if the ground can’t be back-filled some more so as to lower change in height to around 200mm.

        • Why not just build a step between the patio and the ground? It’ll probably look better too. YOu could probably do it yourself using bricks loose laid and dug into the earth – then backfill between the bricks and the patio and top with paving bricks or slabs. You don’t have to do it all the way along the patio – just a couple of metres.

  11. Thanks for the response, Yes it is metal. I review M of SANS 10400, however it does not give me any angle of the incline stairs. Can you furhter elaborate on the angle of the stairs.

    • Hazel if you are convinced that the stairs are dangerous, I suggest you call your local authority and ask them for advice.

  12. Good day,

    I would like to know if a fire escape staircase is required to be constructed for a 100m2 concrete mezzanine floor? The mezzanine floor is to be changed into a small office for about 5 to 10 people. The mezzanine level forms a first floor of an exisitng single storey building and has an internal staircase already with fire extinguishers fitted to walls. Can you help?

    Regards,

    Dillon

    • You wouldn’t normally need a fire escape staircase for a mezzanine. More importantly, the area needs to be “fit for purpose for which it is intended”. In terms of a mezzanine floor, I think there needs to be 2,1 m above and below the floor. Also only a certain number of people are permitted to “occupy” a certain sized space.

  13. if there is specific legislation requriements for stairways for a company be it internal or outdoor, can you please let me know how i can find the written legislation requirements or regulations

    • There are no specific laws that relate to businesses (vs homes) and the regs relate to stairways in general – i.e. in/out no difference. If you want to see what SANS 10400 Part M Stairways says, you can buy the standard from the SABS, or pop into your nearest office and you can read the standard in their library.

  14. I am wrkingfor a company in South Africa. My question is that we have mental stairways, however it incline very high coming down the stairs, is there a specific specfication for the stairway as per legislation requirements, please advice

    • Hazel I presume your stairs are METAL. The NBRs don’t distinguish between different materials, but the SANS (deemed-to-satisy requirements) do give guidelines in terms of the height of risers. This has a direct effect on the incline. I have added info to this section. I hope it will be helpful. If there is still something you need to know, please post another query.

  15. Good Afternoon,
    I want to install a handrail on the exterior stairwell of my sectional title apartment, and I want to know what the building and safety standards are. Can you help please,
    Thanks and Regards,

    • It needs to be erected about 850mm – 1m above the stairs and should be securely fixed so that it doesn’t form an obstruction. The regulations are more concerned that railings are erected for safety purposes rather than what they are like. Common sense will guide you in terms of the finish of the handrail. e.g. If it is wooden it must be sanded smooth and properly finish for longevity. If it is metal, the same applies, though you will also have to rustproof the metal.

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