Since April 2011 building industry regulations have been revolutionised, but the glass industry is lagging behind in its transformation to accommodate these regulations. This is the opinion of Nick Wright, managing director of Nick Wright Consulting. He says the glass industry has a lot of catching up to do with regards to implementing and adhering to industry regulations.
According to Wright, he has witnessed many cases where negligence could potentially cause huge problems for clients, not to mention the people visiting these glazed installations after completion. One such example was at a shopping centre. “The shopfront design was to hang glass four metres high across a span of over seven metres.” Sliding doors were then hung from the glass – in total a ton of glass. “Five 6mm screws were attaching the glass to a thin steel lip channel. The glass was ‘stiffened’ with cantilever fins screwed only into ceiling board.”
Wright says the project mentioned above is by no means the only one where discrepancies like this are overlooked. “I was commissioned to survey shop fronts in a shopping centre which has been trading for over 20 years with no certificate of occupancy with similar issues.”
For him a worrying trend surfaces in projects where these structures are signed off by an installer. “They are allowed to do this when the installation meets the deemed-to-satisfy rules, but they are most certainly not allowed to sign off bolted applications, frameless doors, fins taller than four metres and other variations to SANS 10400 Part N.”
Wright says the problem may lie with the glazing sub-contractors who copy techniques from other sub-contractors or do an installation at the insistence of professionals who know little better. According to him, discrepancies such as this should not be happening as all the regulations are in place to prevent it from occurring. “I believe the regulations are sufficient to ensure a successful outcome.”
He says there are so many stages to be worked through between a client and the completion of a glazing job that even if actually completed by the individuals responsible for each stage, the holistic understanding of the aesthetic, function and load-bearing requirement of the shopfront is often missed.
Overview of current regulations
According to Wright, a revised Part A of the National Building Regulations came into force in April 2011. The regulations require the owner of a building to appoint competent persons, where those are needed, at the drawing submission stage. “Documentation, signed by a competent person, backing this up must be submitted.”
Wright says one way of circling around Part A is to state that competent persons are not required and that all is built according to the deemed-to-satisfy requirements. “If there is a glass installation outside SANS 10400 Part N, a competent glazing person or facade engineer must be appointed.”
He says an installation outside SANS 10400 Part N includes glazing to buildings with a wall height of more than ten metres, frameless glass (bolted) doors and windows (apart from some shower doors), glass balustrade as well as a glass floor installation. Also outside 10400 Part N are all overhead glazing in roof-light installations, as well as windows supported by glass fins taller than four metres, glazing to swimming pools and glass dimensions exceeding these in the tables of SANS 10400 Part N.
In November 2011 the XA Energy-Efficiency Regulation came into force after eight years in the making. “This is further described in SANS 10400 Part XA and SANS 204,” says Wright. He adds that the requirements specify that inner alia offices, shops, hotels and domestic residences must be proven to be energy-efficient. “The regulation has been designed with a payback period of ten years in mind.”
Regulation A7 N states that the owner must include fenestration system details that must be in accordance with the energy usage requirements of Regulation XA on the layout drawing for municipal approval.
Wright says the fenestration energy-efficiency deemed-to-satisfy requirements are covered in the SANS 10400 Part XA.Buildings with natural ventilation and fenestration to floor area ratios less than 15% are only required to meet air leakage certified maximum values for opening and fixed windows and pivot doors.
He says that if fenestration to floor area ratios exceeds 15%, the design must be to part 4.3.4 of SANS 204. “Above 40% double glazing may be required.” For roof light glazing the deemed-to-satisfy requirement also comes into play. In projects where the roof-light area exceeds 10% of the area of the room below which it serves “then double glazing with low E is required with a U value of not more than 2W/m2.K and a solar heat-gain coefficient of not more than 0,25.”
In March 2012 the reviewed SANS 10400 Part N Glazing Regulations were published. Wright says that in the reviewed version is mostly the same as published previously, but an additional requirement for the quality of glazed windows and doors to meet SANS 613 “fenestration products” was added. “This requires testing for air infiltration (as required in the energy-efficiency regulation) and water penetration (required in Regulation N1 Glazing).”
The building industry puts lives and livelihoods at risk by not following the rules. “Some of these are the elite of the building industry, individuals with university training and countless years of collective experience. They are being hoodwinked by glazing subcontractors who themselves use techniques copied and pasted from some other glazing sub-contractor or on the insistence of someone who has seen this sort of thing done overseas. Maybe it saves costs or gets the job done at a faster pace.”
He believes that taking such a risk could lead to dire consequences. “The glazing regulations, which are meant to be proactive, have become reactive. Only if it falls down or hurts someone will something be done. Let’s hope no one is killed,” Wright concludes.
Nick Wright Consulting
Tel: 082 808 1452