Glazing
Glazing and the Glass You Use for It-Part N
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
This exerpt is from Wikipedia about Glazing
Glazing, which derives from the Middle English for ‘glass’, is a part of a wall or window, made of glass.[1][2] Glazing also describes the work done by a professional “glazier“. Glazing is also less commonly used to describe the insertion of ophthalmic lenses into an eyeglass frame.[3]
Common types of glazing that are used in architectural applications include clear and tinted float glass, tempered glass, and laminated glass as well as a variety of coated glasses, all of which can be glazed singly or as double, or even triple, glazing units. Ordinary clear glass has a slight green tinge[4] but special colorless glasses are offered by several manufacturers.[5]
Glazing can be mounted on the surface of a window sash or door stile, usually made of wood, aluminium or PVC. The glass is fixed into a rabbet (rebate) in the frame in a number of ways including triangular glazing points, putty, etc. Toughened and laminated glass can be glazed by bolting panes directly to a metal framework by bolts passing through drilled holes.
Glazing is commonly used in low temperature solar thermal collectors because it helps retain the collected heat.
Thank you Wikipedia
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Lighting and Ventilation
Subject:
Glass Panel breakage
Message:
As part of an extension to the first floor of our house we had a new oak staircase fitted and this included six glass infill panels. The work was carried out by Hallmark Glass and Glazing Ltd of 49 Potters Field, Harlow CM17 9BZ in July 2011 (Tel No. 01279 410304). Our problem is that this morning
the long glass panel going up the stairs exploded and shattered, causing considerable shock, from which I have hardly recovered. I got in touch with Hallmark and they maintain that the work is outside
their warranty period and there is nothing they can do. My point to them is that glass doesn’t just break unless there is a fitting problem. I would be pleased to know from you where I stand on this and what action I can take against Hallmark. You advice would be greatly appreciated.
John Farrow (Tel: 01582 769975). We live in Hertfordshire.
Gary I don’t think so. It is not even mentioned in the regulations! My understanding is that it could be used in addition to the correct type of glass as an added safety factor.
I agree in part. But if a smash and grab safety film was applied, wouldnt this conform.
Steve the National Building Regulations apply to all glazing. There are tables in SANS 10400 Part N, Glazing that state nominal pane thickness in relation to maximum pane area and type of glass.
If it is vertical glass that is supported by a frame on all sides in an external wall of the building, where the height measured from the ground to the top of such wall does not exceed 10 m, then it has to be monolithic annealed glass 10 mm thick; or toughened safety glass that is 8 mm thick.
The drawing on this page is taken from the regs and shows when safety glass is not required.
If someone falls through your glass – or walks into it and is injured – you could be sued.
Hi
We are about to open a retail store with street front access in Cape Town CBD. We have just been told that our glazing may be illegal – it’s standard 6mm non-safety glass, only one or two of the 6 or so 3m x 2m panes is even laminated.
Are there any legal stipulations for glazing in retail space? And if so, would our store be in contravention of these rules?
My experience with Howick was the pits 🙁
When my mom sold her house in Howick a couple of years ago the municipality planning office did not have plans on file any more as they had lost them when the municipality offices moved. My mother had to have the plans redone from scratch at her own expense. Lack of caring by public servants for the people who pay their salaries is inexcusable.
My own experience is different; unfortunately some officials do not care whether there are historic issues and whether the building does or does not conform to these. A friend of mine recently sold her house in Howick and the Municipality refused to issue her with what she needed to finalize the sale until she had a glaziers report. Luckily her home complied and no additional cost had to be incurred other than the report itself.
Unfortunately their standard answer is “you are welcome to take us to court”, but this is not a reality when a sale is reliant on their approval.
Hi Thando,
Agrément SA, part of the Department of Public Works, is the body that issues certificates for construction materials and manufacturers. You can find all the info you need on their website here: Agrément SA
Hi Mervin,
The new regulation that you are referring to is a new part and was added to SANS 10400 in 2011, Part X deals with environmental sustainability, and Part XA deals with energy usage in buildings. You do not have to use Low E glazing, BUT your building must conform to the new Energy Usage regulations. You can read more here: energy-usage If you need any assistance with your calculations you can contact John Crook at jdctri@gmail.com and 073 144 2600 or visit his website http://www.sansrvalues.co.za/
I’ve been a glazer and sand blaster for about 15 years now and aluminium manufacturer for 10year but I don’t have a certificate. I now want to open my own company but don’t have a certificate.
How and where can I get the certificates necessary to be qualified as a glass glazer and aluminium manufacturer.
Hi there
I just want to understand the regulations for when Low E glazing becomes a necessity when building a house. Is it not the owners decision on whether they want normal glass or Low E glass. Can the municipality insist on new buildings having Low E glazing and if so when did this regulation come into being and where can I read up on it?
Thanx, Mervin
Hi Terry,
You will have to contact the SABS and have your product approved by them. As far as I know they will refer you to Agrement SA (www.agrement.co.za) who will need samples to test and then issue you with a certificate before you can take the product to market. The SABS offices contact numbers are on this page: https://sans10400.org.za/sabs-contact/
Good day.
I have made and disigned a aluminium stackable door system for patios and lapas.
It is an aluminim frame glazzed with 2mm Plexiglass,acrylic.What are the regulations if any for the use of arylics for glazzing.I have fitted it in my patio and have recieved alot of intrest in it.If I would start to manufacture and fit what regulations do I need to adhere to.
Please could you help or send me in right direction to move forward.
Regards Terry
Howard, first of all there is nothing in the current (NEW) SANS 10400, Part N Glazing that mentions any type of certificate. The new Part A General principles and Requirements which waas published in 2010 has a form that the appointed competent person is required to fill in. The section on glazing asks these questions, to which they reply Yes or No:
“The type and fixing of glazing is in accordance with
SANS 10400-B [which is Structural Design]
the detail requirements of SANS 10400-N
The selection of the glazing is in accordance with the detailed requirements of SANS 10400-N”
NOTHING about certificates. But there may be something in the municipal by-laws that requires a certificate. If they didn’t ask for it then, I agree with you that they can’t ask for it retrospectively. Presumably they gave you an occupancy certificate? In which case they approved the building. Fullstop.
And yes the new regs do require safety glass in cottage pane doors, as you will see from the drawing on this page.
The new Building Regulations came into effect in 2008 (progressively until last year – as I say above, Glazing was only published in 2010). Until then all the SANS (previously published as South African National Standard SABS 0400-1990) were regarded as the applicable Code of Practice for compliance with the NBR. I have given you the link to download these. NB They are available free from this website and from the SABS. You are required to purchase the new regs.
You will see in the old document that safety glass is a requirement in certain instances, see pages 96-99. Doors, specifically are referred to on page 96. “Any pane of glass installed in any door shall, where not made of safety glass, be not more than 1 m2 in area and shall have a nominal thickness of not less than 6 mm”. I doubt that cottage panes would be more than 1 m2 – no idea what thickness would have been used. But for the municipality to make any demands more than a decade after completion is ludicrous.
Help!
I built my home in july 2002. I have French cottage pane doors which
open onto a patio. At the time i got a reputable glazing company to do
the entire glazing job at my home. This they did and i paid them
accordingly. I have now been asked by the municipality to supply a
glazing certificate, which i honestly dont recall receiving. What
where the glazing regulations in place in 2002? I believe you now
require safety glass which may not have been installed originally. Can
you advise what i should do as it seems quite an expensive excercise
to have to put in safety glass when i have been living here without
incident for 11 years
Laurinda I suggest you contact a reputable manufacturer and/or installer. The new Part X:Environmental sustainability & Part XA: Energy usage in buildings deals with fenestration [fenestration = “any glazed opening in a building envelope, including windows, doors and skylights” & fenestration area = “area that includes glazing and framing elements that are fixed or movable, and opaque, translucent or transparent”] and cross-references SANS 204: 2011 Energy efficiency in buildings, which deals with different types of glass in relation to the new energy efficiency requirements. It isn’t simply the type of glass you should use, but also the orientation of the building and % of glazing included. Not as simple as it used to be when nobody cared much about energy efficiency issues.
Valmarie, The new Part X – Environmental sustainability – and XA – Energy usage in buildings – deals with fenestration [defined as any glazed opening in a building envelope, including windows, doors and skylights].
This Part of SANS 10400 has a section on fenestration that states:
1. Buildings with up to 15 % fenestration area to nett floor area per storey comply with the minimum energy performance requirements.
2. Buildings with a fenestration area to nett floor area per storey that exceeds 15 % shall comply with the requirements for fenestration in accordance with SANS 204.
So the percentage relates to all forms of fenestration, including both doors and windows. And it doesn’t say you CAN’T have more than 15% – just that if you do you must do it correctly in accordance with the Standard (SANS 204).
SANS 204 doesn’t only look at the glass used, it also considered the orientation of the house and other factors, and is rather technical.
Amongst other things, there is a table that gives the “worst-case whole glazing element performance values” for different types of glass in relation to the type of framing e.g. aluminum and steel vs timber, PVCu, aluminum “thermal break” framing.
The Standard states: “With glazing, this standard requires that total U-values and SHGCs shall be assessed for the combined effect of the glass and frame. The measurement of these total U-values and SHGCs are specified in the guidelines of the National Fenestration Rating Council (NFRC).
The method used in this standard is based on the system performance of glazing being assessed in accordance with NFRC 100 conditions.”
You can get the necessary info from manufacturers and suppliers, but it is essential that the info (particularly the U- and SHGC-values) are for both the glass and frame combined.
Be advised that your best approach will be to get a competent person to help you.
The regulations are not this definitive. If someone is trying to persuade you that the regs say it must be sandblasted … ignore… if your wife wants you to have it sandblasted … you might want to do it. But it isn’t law. Though do realize that if it is a bathroom window it should be opaque … your wife will appreciate this!
Hi everyone.
I am looking for the regulation that defines whether a western facing window needs to be sandblasted or covered. I have a double storey house with a large western facing window above the entrance but it is covered by the entrance roof. Does it need to be sand blasted???
Thanks in advance!
Apologies for the delay in responding to your query Carol; we had a glitch on the site in terms of general “Contact Us” queries. However it is important for you to know that when SANS 10400: Part N Glazing was updated (2012) the requirements for safety glazing were one issue that was addressed – and several amendments were made.
First of all, all “safety glazing material” must comply with the requirements of SANS 1263-1, and individual panes of safety glazing must be PERMANENTLY marked by the installer so that the markings are visible after installation.
Safety glazing materials must be used where [and these are amendments to the Standard, so may not have been complied with if the glazing was installed prior to 2012]:
“1. doors and sidelights form part of any entrance up to 2 100 mm from finished floor level;
2. a window has a sill height of less than 500 mm from the floor or external ground level;
3. a window has a sill height of less than 800 mm from the floor or external ground level without any permanent barrier that prevents persons from coming into contact with the glass panel, and is so placed that persons are likely, on normal traffic routes, to move directly towards such window; (NOTE A barrier could be any feature, i.e. a heavy bar across a window, or a flower box placed in front of the window, that will provide a physical or visual barrier between the glass and a person.)
4. a bath enclosure or shower cubicle is glazed, or where glazing occurs immediately above and within a distance of 1 800 mm horizontally or vertically from a bath or shower;
5. glazing is used in any wall or balustrade to (or immediately adjacent to) a stairway, ramp, landing, pathway, patio, veranda or balcony;
6. glazing is used within 1 800 mm of the pitch line of a stairway or the surface of a ramp, landing, pathway, patio, veranda or balcony;
7. glazing is used in internal partitions, which are within 2 100 mm of floor level.”
There are a few other requirements, but they won’t apply to your situation.
The Standard also specifies (amongst other things) the maximum pane size and nominal glass thickness for the different types of glass used for exterior doors and windows: “Dimensions for vertical glass supported by a frame on all sides in external walls in buildings where the height measured from the ground to the top of” the “wall does not exceed 10 m.
Maximum pane area (nominal glass thickness in brackets)
Laminated annealed safety glass: 2,9 (6 mm), 4,3 (8 mm), 5,7 (10 mm or 12 mm)
Toughened safety glass: 1,9 (4 mm), 3,0 (5 mm), 4,5 (6 mm), 8,0 (8 mm, 10 mm or 12 mm)
I have added a drawing from the Standard that shows very clearly what the safety glazing requirements are for exterior doors and windows.
From what I understand, windowglass cannot exceed 15% of netto area,
we want to put in sliding doors, if exceeding the 15% can one use
E-glass, or does the 15% includes e-glass and normal glass for area
Hi Jonathan,
If you have a look at our page on “Glazing” you will find a few guidelines for what you need. For more detailed information and to purchase the relevant section you can go to our SABS-Contact page where you will find all the numbers countrywide.
I’m looking for the regulations that govern glass and the installation
of glass (e.g., shower doors must open outwards, patio doors must have
toughened glass etc…).
Where would I find these regulations?
I have just moved into a rented property and need clarification on
glazing requirements. All the sliding doors have safety glass, but
what does concern me is that none of windows, waist level and lower
have safety glass.
I have children and this is a double story house.
Please urgently send me an answer and a reference that I can forward
to agent or landlord.
Thanks
Carol
Please advise on the regulation applicalbe for the type of glazing
required in cottage pane sliding sash windows.