CURTAIN WALLS have to keep the weather out and the people in. We provide design review and full-scale testing to make sure that these systems do this reliably for the life of the building. Premature failure is likely to significantly reduce building life because replacement or repair is a large undertaking requiring a vacant building, extensive exterior access and replacement of all interior finishes in perimeter rooms. For this reason, prudent developers insist on having an independent Façade Consultant on board and ‘Mock-Up’ Testing for all their buildings.

Curtain Wall Laboratory Testing or Mock-Up Testing was pioneered by A.A. “Sak” Sakhnovsky from the University of Miami in the 1950s and 60s. The Laboratory provides a structure to which the curtain wall contractor fixes his specimen, which is then enclosed to form an air-tight chamber. Mock-Ups are usually at least three modules wide and two stories high but can be much bigger, and for such large mock-ups they must include movement joints. Besides the basic tests of Air Infiltration, Static Water Penetration and Structural Load, there are several procedures and tests designed to verify the performance of the wall in accordance with the specified standards and performance criteria.

Laboratory Testing verifies that the design of the proposed system is capable, when assembled under ideal conditions in the laboratory, of meeting the design criteria (for example, air and water tightness and wind load). It also shows the contractor’s team where the critical details are and the importance of the workmanship. Every large job should be tested whether or not the system has been tested before because every job has different floor-to-floor heights, mullion spacing and perimeter details. There is just too much at stake not to verify performance by testing a valid prototype for the actual building.

Our laboratory can accommodate 12 or more mock-ups at a time in addition to the ability to accommodate large mock-ups (widths of 15m and heights up to 22m have been tested) and very high pressures. We are accredited by UKAS, EIAC and GAC to ISO 17025 and our results are therefore universally acceptable. The lab is managed by our Curtain Wall Testing Manager, Clarence Facun, who has been with us since 2003; he and his team of engineers and technicians have conducted hundreds of tests.

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How it works

TBWIC Curtain Wall Testing Team offers highly specialised and independently accredited full-scale laboratory testing facilities for curtain wall systems. Headed by our Testing Manager, Mr. Clarence Facun, our team of experienced engineers and technicians, provide you with the expertise required to complete your testing requirements in the most efficient and professional manner.

We can provide laboratory and on-site testing for Curtain walls and other façade elements such as windows & doors, glass walls, skylights, metal or glass roofing, metal cladding, granite walls, etc.

Characteristically, a Curtain Wall is often defined as a thin, aluminium-framed wall containing in-fills of glass, metal panels, or thin stone. The curtain wall frame is attached to the building structure and does not carry the floor or roof loads of the building. Curtain wall & other façade elements require performance testing to evaluate if its design principle has been met and is structurally safe and if its assembly and installation can guarantee a good protective shield for the complete building.

Performance testing of the specimen, both prior to construction and during construction, is a well-established and respected element of quality assurance. Testing representative segments of curtain walls, or windows, for example, comprises three basic tests, plus three others. The basic tests are Air Infiltration, Water Penetration and Structural Load.

For these tests, an air-tight chamber is constructed on one side of the specimen. The Air Infiltration test consists of measuring the flow of air from the chamber and deducting from it the flow of air attributable to the chamber itself. The Water Penetration test consists of creating a pressure differential across the specimen (with the lower pressure on the inside of the specimen) and spraying water uniformly on the exterior. The Structural Load test consists of pressurising the chamber (both positive and negative) to simulate wind-generated pressures. Generally, the water penetration test is repeated after the structural load test to ensure the performance and integrity of the system has not been affected.

Three additional tests are as follows: The Dynamic Water Penetration test, where air from a large wind generator is directed at the specimen at the same time as the water spray; The Seismic test, where one of the support beams is jacked in three cycles of lateral displacement. The Thermal Cycling Test consists of placing an insulated chamber on the exterior side of the specimen. The temperature in the chamber is varied from ambient to a selected low temperature and then to a selected high temperature over a period of 8 hours, while the temperature on the inside of the specimen is maintained at room value. This simulates cycles of annual changes in temperature. The water penetration and/or air infiltration test are conducted again after this procedure.

Mock-up Site testing comprises either a chamber test (much like the mock-up test but generally more limited) or the hose test. These tests are intended to check the workmanship and that the design, which passed the mock-up testing, is being properly constructed on-site. The hose test consists of spraying water at the system following a prescribed procedure and as per international standards.

For Curtain Wall testing to be carried out, an agreement for Testing needs to be prepared, and this is usually done by the Technical Manager or Project Specialist. This should include reference to the specification for the testing, a list of tests to be performed, payment requirements, facilities, safety, scheduling, Privacy & Confidentiality, and all other necessary information. After which, a contract or client request is reviewed and evaluated to ensure that each requirement is adequately defined before proceeding further.

When a proposal offered by TBWIC is accepted by the client, they will then have to send a confirmation of approval. The contract will be valid when we receive the Purchase Order or notice to proceed from the client. Mock-up shop drawings and test parameters are being evaluated, after which, the Method Statement is being prepared and submitted to the client for approval. When approved, the design and erection of the test structure including enclosure are observed. Consequently, the client can begin to install their mock-up specimen. After installation, the chamber, test material and testing equipment are verified; this will then be followed by the actual testing. Lastly, a Final Report is submitted to the client.

Curtain Wall testing must be done to identify and rectify improper design, improper fabrication and improper installation. Tests are a must-do and should be carried out in every project. This helps the Project Manager to act proactively, thus the company can save valuable material in the form of modification, valuable time and money. The performance of the material as per design requirement will be assured and peace of mind, on the functionality of the system, is achieved.

The following are the list of Standards (with UKAS, GAC and EIAC accreditations) utilised by TBWIC Curtain Wall Testing Team:


Exterior Windows, Curtain Walls and Doors; Air leakage
ASTM E 283
Installed Exterior Windows, Curtain Walls and Doors; Air leakage
ASTM E 783:02

Exterior Windows, Doors, Skylights and Curtain Walls; Structural performance by uniform static air pressure difference (Procedure A)
ASTME 330/E330M

Exterior Windows, Doors, Skylights and Curtain Walls; Water penetration by uniform static air pressure difference
ASTM E 331

Exterior Windows, Doors, Skylights and Curtain Walls; Water penetration

Installed Exterior Windows, Doors, Skylights and Curtain Walls; Water penetration by uniform static air pressure difference
ASTM E1105

Safety Glass; Performance Test
ASTM E2353

Sheet Metal Roofing & Siding Systems; Structural Performance by Uniform Static Air Pressure
ASTM E1592


Windows, Curtain Walls and Doors; Water penetration using dynamic pressure
AAMA 501.1

Exterior Walls; Thermal cycling
AAMA 501.5

Windows and Doors; Air permeability
AAMA 501.1

Curtain Walling; Vertical inter-story movements
AAMA 501.7

Storefronts, Curtain Walls and Sloped Glazing Systems; Static test method for evaluating seismic and wind induced interstorey drift
AAMA 501.2
AAMA 501.4


Windows and Doors; Watertightness
BS EN 1027

Windows and Doors; Resistance to wind load
BS EN 12211

Windows and Doors; Impact resistance – soft and heavy body impactor
BS EN 13049

Curtain Walling; Air permeability
BS EN 12153

Curtain Walling; Watertightness under static pressure
BS EN 12155

Curtain Walling; Resistance to wind load
BS EN 12179

Curtain Walling; Impact resistance
BS EN 14019

Whole Buildings; Air permeability test
BS EN 13829
BS EN ISO 9972

BS EN 1026

Safety Glass; Performance tests
BS EN 14428


Building Envelopes; Air Leakage
CWCT Section 5

Building Envelopes; Water penetration – static method
CWCT Section 6

Building Envelopes; Water penetration – static method
CWCT Section 7

Building Envelopes; Water Penetration – hose test
CWCT Section 9

Building Envelopes; Wind resistance – serviceability
CWCT Section 11

Building Envelopes; Water resistance – safety
CWCT Section 12

Building Envelopes; Impact resistance
CWCT Section 15

Glaze Roofing; Safety & Fragility Test (Temperature Range 20 °C to 50 °C)
CWCT technical Note no. 67


Whole Buildings; Air permeability test

Safety Glass; Performance tests
ANSI Z97.1


Safety Glass; Performance tests
CPSC 16 CFR 1201.4 (1.1.12 edition)


Thomas Bell-Wright International Consultants is Accredited to ISO/IEC 17025:2017 by United Kingdom Accreditation Service (UKAS), Emirates International Accreditation Center (EIAC) and GCC Accreditation Center (GAC) for Building air leakage testing and water permeability, water leakage field check and air leakage and smoke tests to indicate leakage locations.

UKAS / ISO 17025
GAC / ISO 17025
EIAC / ISO 17025


GCC Accreditation Center
ISO/IEC 17025:2017
ATL 0017



Since 1995 we have provided our specialist knowledge and expertise on over 1,000 of the region’s major architectural projects.


Having worked on many prestigious projects, our clients have always been satisfied with our input and have always recommended us for more. We are proud to present some of our clients’ testimonials under Facade Consulting, Curtain Wall Testing and Fire Testing.