Product Description

The Thermosash PW40 is a four sided mechanically glazed engaged curtainwall, that is; expressed horizontal transom elements and vertical mullion elements - similar to the high performance PW400. This unitised curtainwall suite is suitable for low or high rise applications where small spans or where smaller panes of glass are envisioned. The PW Series Suites have been extensively used and proven in New Zealand and our export markets since 1985. 

The weathering design of these suites follows recognised international curtain wall design principles - rainscreen pressure equalisation and system drainage - which requires primary and secondary weathering. The rainscreen acts as a primary water-stop, the second airseal and cavity acts as a backup to collect and drain away any water that manages to penetrate the primary rainscreen barrier.

All internal cavities of the system are designed to be pressure equalised (i.e. no pressure differential between the outside face and any internal cavity). This feature allows the water which penetrates the rainscreen to drain freely back to the exterior. The rear air seal is critical to the system's weathering performance as air infiltration acts as the medium which transports water through to the building's interior, i.e. it is the prime cause of any leakage.

Design limitations of the Unitised Low Rise suite are;

  • Lower floor to floor heights than PW1000
  • Best used where the site has low wind loads
  • Most appropriate to smaller module sizes
  • Where building movement is low

It is recommended to discuss your project with us early to determine the best suited suite for your needs.

Integrated Elements

Almost an unlimited type of materials can be integrated into a unitised panel, including different glass types, metals, brackets to receive externally mounted fins, louvres, venetians or building signage for example. 

Section Sizes

  • 75/100mm Mullions
  • 75/100mm Transoms

Performance / Testing

Thermosash owns and operates the largest façade testing facility in New Zealand where we test our systems and custom designed suites to ensure compliance with the below codes or project specific requirements:

  • AS/NZS1170 (Structural Design Actions)
  • NZS4211 (Performance of Windows)
  • NZS4223 (Glazing in Buildings)
  • NZS/AS4284:2008 (Water / Air Pressure/ Air Leakage - Meets and exceeds minimum requirements)

All the Thermosash suites are independently laboratory tested to IANZ (International Accreditation New Zealand). Test certificates are available on request.

Maximum spanning ability

Thermosash specifically engineers the best suite option for your project taking into consideration span, structural system, and environmental loads (e.g. wind). The spanning ability will vary depending on the above.

Thermosash Suites are recognized as having the largest spanning systems on the market due to our specific engineering capability and the customised nature of the work we complete.

Sizing of modules is generally only limited on the project design requirements, economic considerations, transport and site crane installation limitations. We would be happy to discuss what these might be on your project.


The standard warranty is 10 years from the date of practical completion for these products. This covers workmanship and weather tightness, providing the subcontract includes fabrication, installation and glazing of all components.


Maintaining glass, metals and stone are all particular to the environment that they are placed in: eg. marine, environmental pollution, exposure to natural washing, etc.

It is recommended by almost all material suppliers that building washing should occur every 3-6 months to prevent staining to glass and prevent environmental pollutants from corroding metals and to maintain the material warranties.

A full maintenance manual is provided on completion of a project for all the elements integrated within a project.

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Key Features

This engineered façade product is designed to accommodate:

  • building movements - both vertical and horizontal (seismic)
  • Allows for differential rates of thermal expansion and contraction
  • Connection details to accommodate construction tolerances
  • Structural member strengths comply with Code or project specification
  • Glass design and it's integration with the glazing system to ensure glass warranties are complied with


We recommend using Masterspec 4211TS Curtainwall when specifying this suite.

CAD Downloads

PW40 - 100mm Mullion Single Glazed

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PW40 - 100mm Mullion Double Glazed

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PW40 - 100mm Mullion Fixing Bracket - Slab Top Mount

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Thermosash Curtain Wall Fixing Bracket

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  • Polyester powdercoat - both standard and special colours available
  • Anodised - all anodised colours available - commercial grade 20 Micron finish recommended
  • PVF2 Fluorocarbon finishes - available on request

Relevant Projects

Vector Arena

Vector Arena


Crawford Architects

Mainzeal Construction


Constellation Bus Station

Constellation Bus Station


NZ Transport Agency

Brosnan Construction


Rangi Ruru Girls School

Rangi Ruru Girls School


McIldowie Partners Architects

Leighs Construction


Novotel Christchurch Airport Hotel

Novotel Christchurch Airport Hotel


Warren & Mahoney Architects

Fletcher Construction


UOA Parkwest 507

UOA Parkwest 507





Downer Head Office

Downer Head Office


Aqua Ltd

Naylor Love


Upper Hutt College

Upper Hutt College


Stephenson & Turner

Mackersey Construction