Stick Curtain Walling

Stick Curtain Walling (SCW) may be defined as non-load bearing walls, usually suspended in front of structural steel or concrete framing. The deadweight of the SCW with environmental forces acting upon them is transferred back to the main structure through the SCW fixing points.

SCW is mainly made from extruded hollow aluminium profiles which are finished in either polyester powder coated or anodised finishes and available in a wide choice of colours.

The term “stick” refers to the factory-cut mullions and transoms which are transported to site as loose bars or sticks.  However it is possible to assemble them into a ladder frame often referred to as “ladders” for quicker site assembly.

One of the main advantages of SCW is the wide availability of system choice on the market at very competitive prices and short lead-in times.

The correct process of completing curtain walling for delivery to site within programme requires efficiency.  The mullions/transoms are taped to protect the painted or anodised surfaces, the bars are fed through fully automated cutting  machinery after which they are directed to our CNC area for drilling, notching, and possible assembly into ladder-type format.

At this stage the mullions/transoms are packed on stillages for transportation to the project site.  This enables site installation to commence early while the balance of the Curtain Wall profiles i.e. mill finish pressure plates, external horizontal and vertical cappings, can be cut, machined, drilled and transported to site at a later date when required.

Due to the limited processes required in a factory to allow stick to site early, that advantage becomes a disadvantage when on site, as the method of assembly can be slow. The connections between the vertical mullions and transoms must be sealed correctly with the correct type of sealant (specified by the particular system’s company). The joints of the inner gaskets must be cut and glued successfully if inner vulcanised frames are not used.

A further sub-division of SCW is the choice of system drainage, there being two types -

  1. Zone or Field Drainage – horizontal pressure plates and cappings must be machined to allow air in and to allow water drain out successfully from the wall after heavy rain fall.
  2. Mullion Drainage – water travels across all transoms and collects at the mullion connections and runs downwards, similar to a water down pipe.

The insulated glass units or spandrels panels are held in place by the externally applied pressure plates which are fixed with self-tapping screws at 200 mm to 300 mm intervals and finished off by the external cover cappings, which are snapped into place by hand/soft mallet.

Main Advantages
•  Suited for angular and complex façades
•  Sightlines are slimmer than Unitised Curtain Walling
•  Quicker production processes in the factory
•  Can be transported to site in shorter lead times than unitised facades
•  Sequence of the build can be changed reasonably quickly
•  Aesthetic detailing of the façade can be changed by producing a bespoke capping if required

Main Disadvantages
•  Slow process of assembly on site
•  Gasket cutting and mastic/silicone sealing at mullion/transoms joints is critical to the success of the project
•  Trained and skilled field operatives must be used
•  Glazing progress can be slow as all glass units must be installed from the outside of the building
•  Bad weather can be detrimental to both programme and quality of the finish build as it may stop sealants being applied successfully