Nov 152011
 

Glazing and the Glass You Use for It-Part N

All forms of glazing need to comply with the relevant SANS.

Part N is the section on glazing in the National Building Regulations & Building Standards Act and is short and reasonably sweet.

Essentially you need to be sure that any material used for glazing in buildings is secure and durable and that it is fixed so that it:

  • safely sustains wind actions that one would normally expect wherever you live in South Africa (but not necessarily major hurricanes or tornadoes that might be experienced in other parts of the world),
  • does not allow water to penetrate the interior of the building, and
  • is obvious to anyone who approaches it (if it isn’t, people could walk right into the glass and be injured, particularly if it is completely transparent and not made of “safety glass”).

Of course it isn’t only glass that we use for glazing. There are also a number of plastic and polycarbonate materials, as well as organically-coated glass, which can be used.

When it comes to choosing the best type of glazing for the job, the essential aspect is to make sure that if someone (or an animal) does impact the glazing – or collide with it, they won’t be seriously hurt. Factors to take into account include:

  • the position of the glazing,
  • the number of people who are likely to be able to access the glazed door or window, and
  • the probably behaviour patterns of anyone (or anything) that is likely to get close to the glazed area.

And ultimately, as long as the glazing material is selected, fixed and marked in accordance with SABS 10400-N, all should be well and legal… and safe for all concerned.

NBR Changes that Relate to Glazing

The “new” National Building Regulations are a lot more specific in terms of glazing installations than they were previously. Not only is the maximum pane area and glass thickness specified, but so too are the different types of glass. These are:

  • monolithic annealed glass,
  • patterned annealed and wired glass,
  • laminated annealed safety glass,
  • toughened safety glass.

In addition to this, glass must also comply with the relevant SANS, as must the method of fitting the glass or alternative material used for glazing.

Just be aware that whether you are glazing doors, windows, shower cubicles, shop-fronts or anything else, glazing MUST comply with SANS 10400-N as well as other standards that relate to the manufacture of glazing materials.

Construction Standards of Glazing

The SABS also has a strategic policy that relates to glazing in buildings. The reason for this is to standardize glazing in buildings in terms of:

  • terminology (so that we all understand exactly what the regulations mean and relate to),
  • performance requirements,
  • various methods of calculation,
  • design and construction guidelines,
  • the classification and specification of materials (including dimensional properties).

To this end, the SABS has a sub-committee that specifically develops, maintains and co-ordinates standards in the field of glazing materials that are used in buildings. The committee’s responsibility is to:

  • develop national standards,
  • participate in the development of standards (getting votes, comment and so on),
  • develop and review the programme of work,
  • recommend what else needs to be done to ensure that the South African standards stay on track with international standards.

At the end of the day, the safety of users and installers is paramount.

Here is a drawing from the Standard that provides guidance

glazing

Examples of safety glazing requirements for exterior doors and windows.

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Lighting and Ventilation

  80 Responses to “Glazing”

Comments (78) Pingbacks (2)
  1. hi there
    we have a complex of 13 units which was built in 2007 …all the balconies face North but now suddenly two of the units glass doors and panel next to the doors opening to the balconies are starting to crack. I dont know how to describe the cracks but it looks like somebody has drawn curvy lines only on the bottom halves of the glass. I do remember that the plan approval could only happen if the correct glass was specified. Unfortunately the architect left our country in the meantime. I am sure the correct glass was used, but this curvy cracks are really upsetting. Will it crack totally, maybe injure a tenant?
    any suggestion to what i should do please? Can i have it tested to see what kind of glass it is? Do i have to replace it asap ? why only does it start cracking at the bottom?

    • The glass that was specified should be on the approved plans. But you probably need to contact a senior person at a company that specialises in glass and see what possible explanation there could be. I think it would be wise in any case to replace the glass. I doubt that there would be any form of guarantee on it this after nine years. But rather replace the glass than risk tenants being injured.

  2. Thanks to get that information

  3. I am in desperate need of assistance. K am building in the roodepoort area. I am rold that I have to use low e glass on all windows and doors being fitted. Can someone please assist wether or not if there is a definite ruling on low e glass and wether or not I can use normal glass

    • Carel, Following my email sent to you earlier, I have been chatting to an architect in Jhb who confirms my thoughts that both SANS 10400 XA and SANS 204 are both very difficult to implement. Just a thought – he said in conversation that you can only determine which glass is required once you do the fenestration calculations. Whoever drew up your plans should have done these so that the correct glass could be specified in terms of the new energy regulations. He also said that they generally considered low e glass to be the minimum spec to be used; but he was unable to say where this is stated in the NBR (I know that it isn’t). I’ll do a bit more digging and maybe do an article on low e glass for the web site.

  4. We need advice please! We are building a 2 bedroom cottage, extending the garage with 2 bedrooms and a bathroom. Our plans has been approved by council and received from architect but it states that all windows to be installed must be low e. Do we have to install all of the windows low e as it turns out to be very expensive. There is going to be a gas stove and gas heaters installed. Please help.

    • Is this a spec from the architect or local authority, because there are other options that are acceptable in terms of the NBR. Which area is this in?

  5. Hi,

    We recently built a house however during the construction the 1st glazier when bust and closed down, we then appointed another company to fix the work and complete remaining. Guess what they also went bust !!!
    So whilst our lawyers are busy suing these companies (KIC glass and Urban Aluminium) we need a glazing certificate for our CoC.

    IS there anyway we can get this from anther company? And what would the cost be?

  6. Could someone confirm whether glass windows that are under-spec for their size in an office environment need to be replaced with legal spec glass automatically or only when replacing the glass if broken.

    • As you say it is a legal matter, if anyone were to be injured for any reason or of the glass were to accidentally break the as it is not legal then the insurance you have might not cover your damages. The best would be to contact your insurance.

    • I am building a new house in yhe roodepoort district. We are forced to do low e glass. Is this regulation or can we just comply with the normal requirements set out above ?

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