Safety with Glass in Construction
The National Building Regulations SANS 10400
The South African National Building Regulations are concerned with safety. They don’t say a lot, but they do say that glazing in any building must be secure and durable and fixed so that:
- wind doesn’t damage the glass
- water doesn’t leak into buildings
- people can see clear glass when they approach it and don’t think it is an open space
The regulations also say that glass, including coated glass, must be selected so that if somebody walks into the glass they will be as safe as possible. These regulations rely on SANS to make sure that glazing is done correctly.
SANS 10400, as explained elsewhere on this web site, is basically a collection of “deemed-to-satisfy” rules. Part N of SANS 10400, published in 2012, covers the installation of glazing and safety glazing. This means it is SANS 10400 that tells us where and when we have to use safety glass rather than ordinary clear glass.
Installing Glass Safely
SANS 10400-N (2012) cross-references several other SANS for the safe installation of glazing. For instance, it states that glazing must comply with SANS 613 for impact and wind loads in accordance with the requirements of SANS 10400-B, which of course deals with the structural design of buildings.
It is vital that the thickness and type of glass used is structurally safe. Several tables are given in the NBR for guidance.
The NBR also states that if people approaching clear glass are not likely to realise it is glass, then the glass must be marked as a warning. This can happen very easily if the front of a building or sliding patio doors has clear glass that is kept very clean and doesn’t reflect anything. Anyone walking with any speed could crash into the glass and get hurt.
Where glass is installed vertically, for example in window panes, it is very important that the glass can withstand the impact of wind. So the SABS experts have written a much more detailed standard for glaziers, SANS 10137 The installation of glazing in buildings. This standard also explains when glass can be installed without a frame.
We said earlier that normal clear glass may be used in buildings wherever safety glass is not required.
So where do we need to use safety glass?
There are very strict rules regarding the safety glazing of doors and windows. Ordinary glass can be used in a door pane as long as it is not more than 1 square metre in area, but then the glass must be at least 6 mm thick. If the glass is any bigger than 1 square metre then safety glass has to be used.
If windows aren’t guarded by barriers to prevent people from making contact with the glass, the window sill must be at least 300 mm from the floor. If the glass in a window goes right to the ground and there isn’t a barrier of some sort in front of it, it can be very dangerous. It is even more dangerous if the window is positioned directly opposite a door.
If the person passing building plans at the local authority considers a window to be dangerous, he or she can insist that the height of the window sill is at least 800 mm off the floor. Otherwise, that person can say that the glass used below that level must be safety glass, or if the area is less than 1 square metre, that any other glass must be at least 6 mm thick.
Other places where safety glass must be used include:
- bath enclosures
- shower cubicles
- shop windows or shopfronts that are larger than one square metre
- balustrades or walls to stairways or ramps where the glass used are less than 1,8 m above the pitch line or landing.
What Happens if Someone Gets Hurt?
The glass must be installed correctly, in terms of the rules and regulations. If something goes wrong and somebody gets hurt because safety glass wasn’t installed where it should have been installed, the professionals, builders and suppliers may be sued in a court of law.
The South African Glass & Glazing Association of Southern Africa (SAGGA) warns that even if an architect, builder or subcontractor was told by his or her employer (for example a property developer or homeowner) to install normal clear glass instead of safety glass, that person may be found guilty in court. They say that people with experience and knowledge must ensure that construction is safe.
So if any supervisor or contractor has any doubts about the safety of glazing in a building, however big or small, the answer is to check the National Building Regulations and other relevant SANS. If you think that glass in the building is inadequate or has been incorrectly installed and could injure somebody, you need to find out if safety glass should be installed. If you don’t, you could be found negligent.
[Recognition to SANS10400 Building Regulations]