Buildings ageing badly
A staggering number of commercial buildings and extensions suffer from premature ageing – the fault of inappropriate, poor-quality or incompatible building materials, or just bad design, writes JEFF SALTON.
Australians spent close to $2 billion last year on beauty products (men spent $44 million of that). I’d hate to think what we spent on cosmetic surgery!
Obviously, that says we pride ourselves on looking the best we can. Most of us, fortunately, do not have our looks held up to public scrutiny. Buildings, on the other hand, do – every day.
Some are known for their classic beauty – Empire State Building, Chrysler Building, Sydney Opera House, Eureka Tower, something in Dubai? – I’m sure you could name a few of your favourites. These and other iconic buildings inevitably stand the test of time very well, gaining the affection and approval of occupants and passers-by by ageing gracefully and consistently over many years.
By contrast, buildings that age prematurely look cheap and are unwelcome eyesores in any context, leading instantly to public derision, dissatisfied owners and tenants, and an unanticipated torrent of repairs and costly cleaning and maintenance activities.
In this article we talk to a number of professionals associated with commercial building products to get their ideas on how to avoid ‘ageing’ pitfalls.
NICK TYRELL (COX RICHARDSON ARCHITECTS)
To being with, slapping some acrylic paint on prefab concrete is fraught with danger, says Cox Richardson Architects director Nick Tyrell. “That will need constant maintenance.
“But even a glazed curtain wall – and they are common on commercial buildings – will have areas like the silicon joints and rubber seals which will degrade surprisingly quickly when subjected to UV light.
“There’s not much you can do about that because a curtain wall won’t last forever [in tip top condition]. It’s quite low maintenance but does require careful checking.”
Tyrell says that perimeter sealants may have a typical service life of 10–15 years with proper maintenance. But if these are neglected, the building’s façade can quickly start to look tardy, maybe not from a distance, but if you’re looking to lease space in an office block, then you will get up close and personal.
“Therefore a regular curtain wall inspection and maintenance regime is essential,” he says. “Corner seals are apparently a significant issue, as sealants break down due to weather and UV exposure. Seals are also affected by movement in the building structure, deflections, etc, which cause effect bonding.”
Moving away from the common glass tower, Tyrell makes some interesting observations.
“We’ve done a couple of buildings which have no coating on them. They are naturally oxidising. We used Corten steel.
Corten steel is a ‘weathering steel’ that looks like normal steel initially until the outer surface oxidises to form a stable surface coating after four to six months.
“This ‘rust’ coating protects the steel and stops further corrosion. It doesn’t need oiling or any coating and will last for an extremely long time. It does, however, require a specific welding system.
“If that’s the aesthetic you’re after, it delivers a really good effect. I think it’s quite a beautiful material,” says Tyrell.
He mentions the NICTA Building at Australia Technology Park, Redfern, NSW, as an example of an office building clad in Corten. It’s situated near the Eveleigh Railyards in Redfern and is surrounded by heavy steel infrastructure.
“We clad that building’s solid core components with Corten steel. It’s a common building product throughout the world, used mainly for infrastructure and sculptures but there are many examples of where architects have used it in buildings.
“It’s also taking a different approach where you might say: ‘I don’t want to have to maintain this building. Once it’s there I don’t have to worry about it any more.’”
Nick says that Corten is almost self-healing, that if you scratch it with a knife, for instance, the metal underneath will rust and blend in with the original surface.
Zinc cladding is another good building product that oxidises on the outside and doesn’t corrode any further. It, too, has the same self-healing qualities.
Carefully selected timber products can achieve similar positive outcomes. Tyrell says Cox Richardson has worked on a number of low-rise buildings where the company has utilised western red cedar cladding (such as King Street Wharf, Sydney).
“Western red cedar has natural oils within the timber that resist termites and rotting,” he explains. “It ages and goes naturally grey, there’s no need to keep painting it. That particular building was in a maritime environment so it seemed quite appropriate to use that product.
“What interests us are the materials that age gracefully, rather than disgracefully.”
Nick says builders need to be wary of natural marble and some of the softer stone that can degrade surprisingly quickly. He recommends avoiding these products as an external cladding.
“Buildings that have survived for hundreds of years in Greece made from marble don’t last long in an urban environment subjected to pollution. They also absorb stains,” (avoid white marble benchtops!).
Materials that some may regret Any building with beige pebblecrete on pre-cast – Nick’s not sure it ever looked good but as the decades have rolled by and the grime builds, it looks filthy, drab, cheap and depressing, he says.
HAYDEN KEMP (NFK)
Hayden Kemp’s company, NFK, specialises in stainless steel hardware for commercial buildings. Often his products, like spider fittings and stand-off fixtures, are specified for use on commercial buildings’ glass facades where panels of glass need to be fixed to a concrete or steel structure.
Kemp has seen first-hand what inferior products can do to the look of a building.
He speaks of the ‘tea stain’ effect from which some stainless steel products suffer, often caused by incorrect metal grade selection or substandard element control during the casting manufacturing process.
“Our fittings are exclusively manufactured from high-quality 316 stainless steel,” he says. “In addition to this, we provide an electro-polishing service that increases the metal’s surface resistance to staining and improves the surface brightness for a more defined appearance,” he says.
“People in the building industry should understand the benefits of using 316 or higher grades of stainless steel and should use a reputable supplier. Some hardware we see in the market coming in from overseas is only 303 or 304 stainless steel, and is being sold into areas or applications where these grades are insufficient, which means it won’t last as long or keep its appearance for any great length of time.”
Builders ordering stainless steel products from unknown suppliers are risking their reputation. “They might ask for marine grade stainless steel, which is meant to be 316, but that mightn’t be exactly what they’re getting.
“It’s a bit like buying cheap tyres for a Ferrari – sure, they look good when you drive away but because the quality isn’t there, they’ll under-perform.”
Kemp explains that stainless steel is made up of a number of elements, such as chrome, nickel and molybendum. Stainless steel needs all these elements to be at the mid to top end of the spectrum if the products are to be high quality. The same way ‘old fashioned’ stainless steel was manufactured, before cost became more of a concern than quality.
“Some imported products use these elements at their lower limits to reduce cost, which means an inferior product. Usually a cheap price is an indication as to the product’s quality.”
Kemp warns against buying product from overseas over the Internet. “Get a sample, have it tested or speak with a colleague who can recommend a reputable supplier.” AND find out (a) what your legal responsibilities are as the importer, and (b) what recourse you have against an overseas supplier should the product they deliver not be the same as the samples they first offered.
Another mistake some facility managers make is that they treat stainless steel as ‘stain-free’, says Hayden.
“It’s not an ‘install and forget’ product,” he advises.
“Often a cleaning and maintenance program is required to assure that ‘new look’ lasts a long time.
“But if the products you have had installed are produced with a course satin finish and are located in a salty or dirty environment, subject to human contact (handrails) or environmental pollution, that tea-staining is often the foreign contamination trapped in the surface starting to rust. It’s not always the fittings that are rusting.”
In these instances, Kemp recommends a light abrasive scourer to remove it, or highly diluted acids, marketed as rust converter.
“Check with the fittings supplier before doing any cleaning work, just to be sure,” he notes.
Finally, the big thing that gets Kemp angry about poor-quality stainless steel fittings is that a lot of importers aren’t held accountable.
“It frustrates me the most,” he says. “They should be responsible for quality, and their product should be fit for purpose. They either don’t care or believe they won’t ever get found out about the quality.
“Some products I’ve seen are so poor that in coastal areas even the interior stainless steel products have rusted.”
Therefore, check your supplier’s credentials and have a look at some of their installations before committing.
GARTH WESTON (BLUESCOPE STEEL)
Bluescope Steel’s marketing manager – Australian Commercial and Industrial Markets, Garth Weston, has some good advice for managers thinking of cutting corners with cheaper pre-painted steel roofing products that are available in this country.
His advice is: Don’t! They haven’t been designed for Australian conditions.
Secondly, he says mixing and matching metals that come into contact with each other can result in a galvanic reaction, a form of corrosion that can cut short the life expectancy of the even the best metals. So stick with the same product for flashings, downpipes, etc.
“Colorbond® steel (made by BlueScope) has been designed specifically for Australian conditions,” he says. “We spend around $20 million per year on R&D. A large portion of that expenditure goes towards coating technology. Colorbond steel is a trusted brand in the industry, synonymous with high-quality aesthetic features, and the coatings we use (which underpin the performance) are subject to rigorous testing campaigns to ensure the product can be warranted for up to 30 years.
“The initial paint systems that we used were vinyl paints, and over the course of the past 30–40 years that technology has evolved to best-in-class polyester technology.” Weston says this helps the product retain its colour and gloss better than ever.
“The steel [we use] is a low-carbon steel, made at the company’s Port Kembla steelworks. We use Zincalume®-coated steel as the substrate for Colorbond steel. It’s an alloy comprising 55 percent aluminium and 45 percent zinc.”
Weston says he recalls a batch of imported pre-painted steel product that was installed on some residential roofs in Queensland. “It faded very, very quickly. If you were unlucky enough to get some of your roof supplied in Colorbond steel and the rest with this imported product, the results were pretty ordinary.”
Moreover, he adds that there is another pre-painted steel product from a reputable overseas steel manufacturer that has been installed in some Australian building projects; although the product may perform well in European climates, it doesn’t stand up to Australian conditions “because of our unique environment”.
“The combination of high UV with high temperature and a marine influence means that we ask our products do things that other pre-painted products can’t do.
“That’s a trap that facility managers need to be aware of.
“Even though this overseas product is made by a reputable supplier and comes with some level of warranty support, we still get really nervous about the longer-term performance of those types of products when they’re subjected to the unique Australian environment.
“As a world-leading producer of coated steel products, we assess various coating technologies in order to provide the most suitable products for the Australian market. A number of commonly available alternatives in other markets do not meet our performance expectations.”
Weston says roofing made from Colorbond steel is available in 20 standard colours or any colour of your choice (depending on the amount of steel you require).
“Recently, we have launched Colorbond Coolmax® steel, which can deliver maximum thermal performance with financial and environmental benefits for the operation of commercial and industrial buildings,” he says.
ELIZABETH MCINTYRE (THINK BRICK)
When you think about it, there aren’t too many brick buildings that have aged poorly – as long as they haven’t been painted.
Bricks have a number of endearing qualities that make them the obvious first choice for building material, says Think Brick CEO Elizabeth McIntyre.
“The first is the low maintenance required for brick; once it is laid there is no need to paint or repair and bricks last forever,” she says. “They are durable against all weather conditions.
“Bricks also have wonderful thermal qualities, which allows brick houses and buildings to stay cool in summer and warm in winter, providing a more moderate temperature internally.”
McIntyre says bricks are also known for their excellent acoustic qualities – important in high-density areas.
“Bricks are available in more than 500 different colours. Their appeal is the choice available and also the many different forms of texture. They work well with every other building material, and glazed bricks, for example, can make wonderful feature statements.
“The trend continues for face brick now in internal walls – creating that feature wall with wonderful acoustic and thermal qualities.”
And on the inside …
BILL THOMPSON (CSR LIGHTWEIGHT SYSTEMS)
The most important thing to consider when selecting plasterboard products for the interiors of commercial buildings are their scuff resistance qualities, says Bill Thompson, manager for New Products and Technology for CSR Lightweight systems and fibre cement products.
“Choosing the right quality will help ensure that when it’s painted the wall will retain its good looks longer.”
Thompson says scuff resistance refers to the product’s ability to remain looking good even after receiving glancing blows. “In other words, taking a hit from things that are not going to destroy the wall totally, but could cause it to look bad.
“A poor-quality product will suffer damage from glancing blows, such as having the surface dislodge, or be gouged out, and when the painted surface is marked and damaged the whole wall can look very poor,” he says.
Things that can cause scuffing include office chairs, tea and drinks trolleys, mobile filing cabinets, etc.
The second major class of damage is caused by what the industry calls ‘hard body’ impacts, like when a doorknob punches a hole in a wall when the door is flung open.
“In these situations, when the possibility of hard body impacts exist, choosing the thickest product is usually a wise decision.”
Thompson suggests a plasterboard that comprises a high-density core and heavy-duty paper is suitable for most office fitouts. Product up to 13mm thick will protect against scuffing and knocks and also provide good soundproofing.
CSR markets EC08 Impact Plasterboard® – a high-technology, fire-rated, environmentally friendly, impact-resistant gyprock, with high-density core and heavy-duty paper that has a high recycled content.
“Top-of-the-range products cost on average around 30 percent more than standard plasterboard when installed, but these additional up-front costs could save facility managers many thousands of dollars in repairs and replacement costs down the track,” he advises.
Thompson says it’s worth considering where the high-impact areas are likely to be within the building, such as right-angle corners. Managers, he says, should insist that metal reinforcement be used in such places. He says consideration should also be given to using timber on corners as edge protectors, as well as skirting boards with a sensible design that won’t attract unnecessary scuffing due to their profile, heights and widths.
In fibre cement products, such as those used in some wet areas, durability is usually associated with sheet thickness. Product between 9–12mm is usually best.
CSR’s topline fibre cement sheet product is Cemintel Wallboard®, which has a number of thicknesses for different purposes.
Finally, Thompson advises facility managers not to scrimp on poor-quality paints and finishes. “Choose wisely the coatings you apply to these products, ensuring that they are fit for purpose and will also last the distance.
“It’s pointless painting heavy-duty plasterboard with a lightweight paint that scuffs and marks too easily. It defeats the purpose.”