Archive for ◊ June, 2010 ◊

A fantastic project has been successfully completed with stunning balconies at a flagship development on the river Trent in Nottingham. This development of 150 apartments saw the first ever £1 Million penthouse apartment sell in Nottingham.

Curved glass balustrades

The requirement was for an effective and clean line glass balustrade system that could also be curved. Curved balconies of over 11m in length were achieved without a single post with a clear glass spanning the entire balcony.

Strength and aesthetics

Before installing the developer wanted to see the performance of the balustrades and two load tests of the handrail system were mocked up for them. One test on site and one in the factory. The client and contactor were delighted with the capability of the system and commented they had never seen such an innovative system that combined both strength and aesthetics in a glass railing system.

The original view was to use structural glazed balustrades on the project but with the balcony 2 system the same result was achieved for around half the cost plus half the weight which was also a key factor on the structure of the balconies.

Trent Park developments are looking at using the same system on their next development:

Balcony systems are about to launch and announce the use of self cleaning coated glass as standard on their Juliet balconies.

The glass has already been manufactured for the stock and is on route to the warehouse. We expect to have this ready for delivery mid July.

The glasses to be supplied are specially coated with a nano coating on both sided of the glass making them hydrophobic.

More information on the slef cleaning glass solution by Balcony can be found here on the self cleaning glass area of the website: http://www.balconette.co.uk/self-cleaning-glass/

Balcony Systems do not intend to raise the price of the balconies and thus this development will increase the Juliet balconies value for money and make them self cleaning Juliet balconies.

Balcony Systems have completed an amazing project on the sea front promenade in Bognor Regis.

A beautiful apartment block with over four hundred meter of glass balustrades were supplied and installed in this project.

The developer, Hamlet Homes, had previously encountered problems with staining and corrosion on stainless steel balconies they had manufactured on a different project that was also in a marine location nearby.

They chose Balcony Systems Royal Chrome handrail system for the glass balustrades after seeing the advantages both in the look and also in the long term resistance to the salty air environment.

Many complex curves and “S” type bends on the top level terraces required some experienced surveying and precision manufacturing.

The results are delightful and parties are well pleased.

Tea staining of stainless steels is a relatively common occurrence in coastal locations. Visually, it is a discolouration of the metal surface, which tends to follow the ‘grain’ of any surface finish. Although unpleasant to look at, it is not a serious form of corrosion, and in general does not affect the structural integrity, or longevity of the balcony.

Aesthetically however tea staining is not ideal, and so the information herein is in an attempt to help identify the causes and suggest possible solutions.

Stainless Steel

The term “stainless” steel derives from the development of the speciality steels for modern cutlery industry. It has now been adopted as a generic name for steels developed for any corrosion or oxidation (rust) resistant applications.

The corrosion resistant characteristics of stainless steels are a result of chromium-rich oxide film that forms naturally on the metal surface. Although this film is extremely thin, it is chemically stable and ‘self-repairing’.

Other types of steel such as mild steel suffer from general corrosion where large areas of the surface are affected, but stainless steels, due to their oxide film, are normally resistant to this form of attack.

Common stainless steels used in the enclosure industry are 304 and 316. Both are iron alloys with additional chromium, and nickel. The nickel content in 316 grades is slightly higher than with 304 grades, and the chromium content is slightly lower. However, the most important difference is that the 316 grades have molybdenum as an additive, to improve its resistance to pitting corrosion, which is usually the result of chloride or saline attack. 316 stainless is preferred by balcony and handrail manufacturers due to this superior corrosion resistance, even though it is a higher cost material.

Tea Staining of balcony handrails

Tea staining can be defined as the “discolouration of the surface of stainless steel mainly as a result of chloride attack”

As a first step it is useful to try to understand why, and in what circumstances tea staining can occur. Tea staining of stainless steels is a phenomenon that occurs where water with significant chloride content is in regular contact with the metal surface. This is a common occurrence along the coastal areas of the United Kingdom.

How is tea staining caused?

Although research on the root cause of tea staining has been limited, there seems to be little research on the root cause of tea staining. However the mechanisms involved can be inferred by the pattern of the corrosion, and known factors that can help counter the effect. One of the most common factors linked with tea staining is the surface finish of the material. Smoother, polished surfaces often do not show any signs of staining, so from this it can be said that grooves or troughs in the material are a root cause of the problem. Surface roughness (Ra) is measured in units of micrometers (µm), and is defined as the average deviation of the height of the surface from the mean height. Higher Ra values or irregular profiles are often associated with increased tea staining.

It is reasonable to assume that the base cause of this corrosion is similar to that of many of the other common types of corrosion. The association of tea staining with proximity to salt water means that chloride attack is the most likely cause of the problem. However you would not normally expect the low level of chlorides present in sea water, for example, to have such a dramatic effect. The reasons why this occurs can be deduced by the locations and one of the solutions to tea staining problems.

Reducing the effect of tea staining on stainless steel balconies

One of the most common ways to prevent problems associated with tea staining on stainless steel balconies is to ensure that the surface is washed regularly with fresh, clean water. This would infer that the corrosion is being caused not by the initial contact with salt water, but with deposits of salt building up on the surface and pours of the handrails. Though microscopic the chloride concentration would build up in any surface troughs. As the water evaporates it leaves a deposit of salt in the trough, and the next time the surface becomes wet this deposit concentrates the chlorides naturally present, and increases the corrosive effects. Over time therefore the chloride concentration in these troughs can become high enough to cause corrosion. Note that this would be consistent with the effect that an increasing surface roughness will have on the tea staining effect, i.e. a deeper groove will trap more salty water, which will give a higher chloride concentration.

The location of particular areas prone to tea staining also implies that higher temperatures and humidity have an effect, as does intermittent exposure (for example, spray from rough seas). High temperatures increase the rate of corrosion, but elevated humidity will increase the time taken for the water on the surface to evaporate, and hence increase the time that the higher concentration chloride solution will be in contact with the metal, and it is this contact with the solution that causes corrosion rather than with the resultant solids.

When ordering stainless steel balconies and handrails, the following is a list of factors that should be considered in particular in areas close to the ocean, or where high levels of chlorides occur naturally, or are found in wash waters.

This starts with basic initial material selections, and proceeds into maintenance of the balustrades to ensure a long life, and therefore maximum value for the balcony.

Material Selection – Initial material selection for the enclosure is of critical importance to the longevity of the balustrades. Stainless steel of grade 316 or above should be used as minimum, as lower grades such as 304 are significantly less resistant to chloride attack due to the absence of molybdenum.

Surface Finish – The rule of thumb for surface finishes is that the smoother the finish, the better will be the resistance to tea staining.

Cleaning stainless steel handrails – Regular washing with clean, fresh water or even rain water has a significant effect on reducing the incidence of tea staining in the environments that can cause concern. Where tea staining still occurs despite regular washing, additional protection can be provided by a special coating procedure using a bespoke polymeric resin

Conclusion

Tea staining of stainless steel handrails, balconies and surfaces can be a problem where there are significant levels of chlorides in water that comes into contact with the metal surface. This can be around the coastal locations, or in the interior where ground water contains significant chlorides. Although it does not look very pleasant it tends to be a surface phenomenon only, and does not affect the structural integrity or longevity of the balcony. The cause of tea staining has been examined in some details to help evaluate the potential remedies for the condition. Recommendations to help prevent tea staining include correct specification of the grade of stainless steel to be used, surface finishes to help reduce the problem as well as maintenance procedures, and preventative coating treatments.

Normal designs of balustrades, or shall we say until Balcony Systems Balustrade system was introduced, have always relied on the strength of posts cantilevering from the floor or relied on the strength of glass clamped at the floor to resist the loads at the top.

This is the traditional and frequently seen solution for balustrades, glass or not.

Resisting the loads

The glass balustrades supplied by balcony systems has broken this routine and introduced a refreshingly innovative approach to resisting the loads. Rather than cantilevering the load and thus needing to design a very rigid base the handrail is designed to take loads direct at the design height.

Fixing the handrail to the falls allow the handrail to work as a rigid element which resists the loads. When corners are introduced the special way the handrail parts are connected and the way the glass is continuously silicone sealed to the glass along the long edge of the glass uses the shearing load of the glass from the handrail right down to the base rail. Again this “out of the box” approach allows for clean glass corners and for cornered balconies to require less posts than ever.

Spreading the resistance across the curve

To top these designs some curved balconies, depending on the radii, are amazingly strong without posts! The curved glass railing is a very stable element to the greater ability of the curve to resist a load by way of spreading the resistance across the curve, similar to a brick arch. In addition the glass itself lends additional horizontal support in a fashion that each curved glass panel cannot bend along the vertical side.

Juliette balconies give homeowners the opportunity to install a French door above the ground floor. Either curved or straight, they come with minimal hand rail for a modern look, while also enhancing light into a room and safely providing a clear view out. Available in seven standard sizes from stock (delivered in three days from order), or custom made, and competitively priced, our Juliette balconies are an attractive and popular choice for consumers wishing to make a difference to their home.

Glass balustrades are also available from stock or custom made to suit the style and size of property. Available in curved, stepped or straight designs, balustrades add great character and style to homes. And with our systems there are no clamps between each pane of glass to disturb the view and the glass reaches top to bottom to give an uninterrupted, clearer view. Using the same minimal hand rail as the Juliette balcony and available in easy maintenance anodised aluminium, Balcony’s Juliettes and balustrades are easy to install and offer instant improvement to the look of any property.

Balcony is the UK’s leading supplier of curved patio doors and our stunning range is described by homeowners, builders, installers and architects as giving properties the ‘wow’ factor. Each door comes with high weather rating, thermally broken aluminium profiles, multi-point locking, 28mm double curved glazing with safety glass on both sides and a choice of RAL powder coat colours. A special low maintenance coating is available for the external surface of the glass to minimise the need for cleaning.

Homeowner Peter Nicholson of Whittlebury, near Towcester, modified his 1983 brick–built house to make better use of the space. A two storey extension was built and the layout of the master bedroom altered to suit a 21^st century lifestyle. The bedroom originally had an open balcony which was taking up valuable space, so Peter extended the bedroom to incorporate the area into the room. He fitted a French door and searched the internet for a Juliette balcony to make the installation safe.

Reasonably priced balcony

“There were plenty of companies offering balconies with vertical bars,” says Peter, “but that defeated the object. I wanted to let in the light and have clear views and Balcony offered exactly what I needed. I ordered a standard 3 metre Juliette balcony from stock, which kept the price reasonable.

Great service

“The service from Balcony was great and I am delighted with the result,” continues Peter. “The Juliette was delivered within seven days of order and it was very easy to install myself.”

Depending on the chemical composition and method of application, some self cleaning glass coatings may be more harmful to the environment than others.

The self clening glass coating Balcony systems uses is a patented nano-coating and is based on an environmentally safe scientific process. The chemicals used in the patented process have been in use for over 55 years in the aviation industry, for different applications, and are not found in the “Clean Air Act” or the “Clean Water Act”. There are also no PELS (permissible exposure limits) set by OSHA.  They have implemented, with  extreme eco-friendly philosophy, the highest standards in the handling of chemicals so that any scientific process used is safe to the environment.

Thus, in the manufacture process and application process of the self clean coating an ultra efficient yet simple neutralization system has been implemented that renders the chemicals and their by-products completely safe and inert. We strive not only to protect the environment but to preserve it from any contamination or pollution.

In addition to this the coating itself will reduce the need for harful chemical in cleaning of the glass in future and in this manner will have a positive impact on the enviroment.

Is it important whether or not a coating is classified as “nano” and does it affect the quality itself?

Nanoscale technologies are the development and use of devices that have a size of only a few nanometers. The prefix nano means ten to the minus ninth power (10 ‾‾ ⁹), or one billionth of a meter, a simple metric measurement.

However, what’s relevant is not the thickness of the coating itself (1-100 nanometers or some other “micro” measurement) but rather:

Nanotechnology and self cleaning glass »