What are Concrete Balconies?
There are two main types of concrete balcony:
- Projecting: With this type of balcony the building’s concrete frame forms a projecting platform or cantilever concrete deck. A balustrade is fixed around the exposed perimeter.
- Inset: Traditionally, this is an integrated concrete deck, which is recessed into the building façade. The open side is guarded with a balustrade.
Key Points To Consider With Concrete Balconies
Integrated concrete balconies can be used to stunning architectural effect. However, there are some disadvantages to this type of balcony.
- Finishing works. Traditional finishing methods can be costly and time-consuming. Using Sapphire Cassettes, which come complete prefinished with soffits, fascia and decking, saves time and labour on site.
- Coordinating multiple trades on site often causing confusion and delays. Sapphire Cassette® balconies are manufactured offsite and arrive as fully assembled units, reducing trades on site.
- Visible welds and fixings. Sapphire Cassette balconies are engineered to keep fixings discreet, with prefinished soffits that complete the underside.
- Waterproofing considerations. Concrete balconies tend to be treated like a flat roof and are usually finished with a waterproof membrane. Also, inset concrete balconies are directly above internal rooms, so the interfacing detail between the balustrade and the waterproofing on the balcony needs careful consideration. Sapphire Cassettes are specially engineered to overcome interfacing issues.
- Drainage provision. Traditional concrete balconies with upstands can trap water and form a pond. To meet NHBC regulations, adequate provision for drainage must be considered at an early stage and integrated into the balcony design. Sapphire Cassettes can be supplied with a built-in drainage system that meets regulations and saves time on site.
- Integrated concrete balconies offer no void in which to run unsightly pipes, balcony drainage connections etc. All details can be incorporated into the Sapphire Cassette module offsite, avoiding the cost and hassle of on site works
- Health and safety on site. When installing traditional balconies there is the potential hazard of people working underneath a balcony to fix soffits and fascias. Sapphire’s aluminium Cassettes are delivered to site fully finished, ready to be lifted into position for final fixing from above.
- Glass handling. Lifting and installing large panels of glass on site can be a safety hazard and there is also the risk of damaging glass during handling. With Sapphire’s Cassette balconies, the glass is already in place.
- Overall cost. In most cases, Sapphire’s Glide-On™ balcony system can provide a better all-round solution without a lot of the interfacing issues and costs associated with concrete balconies.
- Thermal breaks. Concrete balconies must have a continuous thermal break along all connecting edges which increases costs dramatically. Sapphire’s Glide-On™ system only needs thermal breaks on the arms.
- Concrete slabs must be thicker than Cassettes® in order to meet the NHBC requirement for a 150mm splashback. Concrete balconies cannot draw rainwater and are therefore required to have a splashback, this significantly increases the weight of the balcony increasing the strain on the building. Sapphire Cassette® balconies have drainage solutions built-in allowing for extra slim cassettes and lightweight balconies. Interestingly the UK is not alone with this, various states in Canada and also NZ regulations require similar requirements.
- Balustrade posts require a minimum thickness in concrete balconies to prevent the underside cracking out when drilling. Sapphire balconies have prefinished balustrades secured into the Cassette®.
- Decking and soffits must be installed on site including pedestals and rails which add weight to the structure and time to the project. Installation typically requires two installers increasing site costs. Sapphire balconies are prefinished requiring only the final decking boards to be secured.120
At Sapphire we’ve had years of experience working with concrete balconies but found so many disadvantages caused unnecessary delays and headaches on site. As a result, we found a better solution that provides all of the benefits associated with concrete and more, without the hang-ups.