Frameless glass building enclosure details:
Secondary steel detailing and layout
Frameless glass building description:
This frameless glass building enclosure forms a strategic part of a refurbishment upgrade to the Clarion Hotel in Dublin Airport.
This frameless glass building enclosure is a single glazed glass box, its vertical wall are 12mm single glazed tempered glass HST, its roof is 25mm laminated toughened hst single glazing
As designers of this frameless glass building enclosure our responsibilities included:
- the design, detailing and coordination of both the primary and secondary steel structure to this framelee glass building enclosure.
- the design detailing and procurement of a framless glass revolving door within the entrance area.
- the design, detailing and procurement of the projecting glass canopy to the left hand side of the frameless glass building enclosure.
- .the design detailing and procurement of stainless steel cladding and pressed channels.
As project managers of framless glass building enclosures, our approach is strengthened our specialist facade expertise in:- Risk Assessment: We strive to build framless glass facade enclosures for their intended service life and assess each and every perceivable facade risk.
- Value engineering: We understand the need for enhanced performance for the most competitive rate and procure without compromising the overall solution.
Frameless glass building enclosure wall selection criteria
The face glass of this framless glass building enclosure is 12mm toughened single glazing. The face glass is Heat soak tested (HST) to minimise the risk of Nickel Sulphide inclusion (NSI).
Face glass sizes of this framless glass building enclosure are typically 2000mm wide by 2400/1800mm high, the sizes were pre-determined at design stage as part of the value engineering approach.
The secondary steel structure was designed and set out so that the face glass could be procured from several glass suppliers.
All of the face glass to this frameless glass building enclsoureis predrilled prior to toughening to receive a counter sunk articulated bolt fitting. The setting out of the predrilled holes to the face glass was critical to avoiding the induction of stress around the hole.
The external visual appearance of this frameless glass building encosure was important to us in respect of minimising roller wave distortion and taling every practical step in achieving glass flatness
Frameless glass building envelope roof glass selection criteria
- The selection of the roof laminate interlayer is an important design consideration for this type of frameless glass building enclosure, reasons include the following:
- Exposure of the laminate edge to the outside climate may induce contamination which will lead to gradual degradation of the surface edge resulting in white fogging.
- Excessive External temperatures can soften the interlayer causing the panes to gradually separate which is a significant risk at the bolt locations.
- The silicon joints are typically 10mm wide by the depth of the glass, for this project detail consideration with the supplier of the sealant was required to guarantee the characteristics of the product. Clear Dow Corning 791 was used on this project.
Interlayer Solution
The interlayer used in the roof glass is ionoplast; it was used for its strength and resilient weathering characteristics. Its stiffness in service was critical to it remaining in-situ in the event of fracture.
Glass Performance
The corporate identity of this frameless glass building enclosure is reflected in full open transparency with single glazing throughout its envelope both vertically and horizontally.
Single glazing has the following properties:
- Excessive heat loss as the face glass has a high u-value, in this instance the u-value been 5wm2k
- Excessive solar gain depending upon the orientation and time of the year.
- Glare due to light transmission.
The environmental strategy counteracted the above glass performance characteristics.
Face Glass Tolerances
Important to all frameless glass building enclosures is working to recognised industry tolerances. For example, point spider fittings can be articulated to allow inplane and out of plane movement.
Out of plane movement horizontally can be achieved by adjusting the length of the bolt. Vertically there is movement in the fitting but a suitably design secondary bracket can afford the designer some flexibility in the setting out of the structure. Tolerances are marginal and steel erection and fabrications tolerances agreed in advance.
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The following is the Frame glass building supplier we worked with on this project:
