System 17 SP Silicone Pointed

SP Silicone Pointed High Rise Curtain Walling

Metal Technology's System 17 SP, considered a structural glazing system, can be used to construct visually impressive all glass façades. The system offers the designer a wide and diverse range of profiles that will provide structural integrity, weather performance, thermal enhancement and importantly can only be seen on the inside of the building. System 17 SP complies with the current British Standards and is considered as an appropriate option for expansive high rise glazed applications. Its classic visual appearance offers the designer a continuous and expansive external glass face to the façade uninterrupted by external face fixed cover caps. The system is further complemented by the option of introducing concealed frameless top hung casement windows.

Performance Overview

Weather Performance - The Curtain Walling has been tested for weather tightness in accordance with the CWCT dynamic test for curtain walling and achieved the following results:

Size Limitation

Air Permeability 600Pa Pass
Watertightness 600Pa Pass
Wind Resistance 2400Pa Pass
Dynamic Water Penetration (Aero Engine) 600Pa Pass
Wind Load (safety) 3600Pa Pass
Air Permeability 0.02m3/h m2 @ 50Pa Pass

Concealed Opening Sash Size Guidance

Maximum height and width cannot be achieved simultaneously. This table provides basic guidance; please refer to size limitation charts in Metal Technology’s technical literature for further details.

Vent Type Vent Width Vent Height Vent Weight
Top Hung 1500 1500 100kgs

Thermal Performance

Metal Technology's Curtain Walling Range, in conjunction with the correct glass specification, is designed to aid compliance with the latest thermal requirements of the current building regulations. The thermal isolator profile has been specifically designed to minimise heat transfer across the mullion and transom.

System 8 U-Frame Values System 17 SP (36mm)
Mullion 2.05 w/m2k
Transom 2.00 w/m2k

The following U-values for System 17 HR are based on a 7m (w) x 8m(h) curtain walling screen.

Metal Technology can provide tailored U-value calculations using their dedicated estimating software to calculate overall project average window U-values for their full range of systems.


Aluminium profiles are extruded from aluminium alloy 6060T6, T5 or T4 complying with the recommendations of BS EN 12020-2 / BS EN 755 Parts 1 to 9. Polyamide thermally broken sections within this system are manufactured from glass reinforced nylon sections capable of withstanding temperatures in excess of 200 ºC.


The system is fabricated in “stick” form, is pressure equalised, and self-draining by means of overlapping the transoms onto the mullion members. Water is then channelled to the exterior of the building via the integral drainage chambers within the mullions. Where the transoms connect to the mullions, the joint is sealed by means of a purpose designed transom end seal. The transom members are square cut and fixed securely to the mullions by means of spring cleats designed to fit into integral ports within the cavity of the transom wall.

The system is dry glazed using proprietary, high performance captive gaskets internally. All internal gaskets are bonded and sealed during construction, using Metal Technology’s own waterproof adhesive to ensure that a watertight joint at all cruciform connections is maintained at all times. The double-glazed units and panels are held firmly in position by means of a bespoke concealed glazing lug. All vertical and horizontal joints are sealed off utilising a closed cell, non-gassing polyethylene foam backer rod with a silicone pointed sealant to the external face.

The system is thermally broken throughout by means of a continuous thermal isolator located between the thermally enhanced pressure plates and all structural members. The thermally enhanced pressure plate shall be held in place by aluminium stitch plates. The pressure plate shall be retained by using stainless steel self-tapping screws. Metal Technology recommends that only A2 or A4 austenitic stainless steel fixing screws are used in the assembly of their products.

Carefully designed fixing brackets have been developed for System 17 SP to allow a secure and simple fix so that all loads can be transferred back to the building’s main structural form with ease.


The range of sections can be provided in either of the following ranges of finishes:

  • Anodised to BS1615 or BS3987 or BS EN 12373-1
  • Powder organic coated to BS6496 or BS EN 12206-1
  • Metal Technology's powder coating is produced to Qualicoat standards.
  • Metal Technology's powder coating is produced to Qualicoat standards. The System 17 curtain walling can accommodate a different colour/finish internally to that used externally.


The system is externally glazed and can accomodate glazing units from 32mm to 36mm.

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