What does CWCT stand for in construction?

CWCT stands for Centre for Window and Cladding Technology. CWCT is an industry-funded provider of standards and guidance across the construction and fenestration industries. From the historic city of Bath in Northeast Somerset, the CWCT publish documents and resources and offer professional advice to a wide range of construction specialists.

Complying with CWCT standards

CWCT standards are designed to ensure that a building envelope is of the highest possible quality. Both building performance and appearance are considered during testing, and it is recommended that qualified installers and supervisors carry out the installation. All installers should be fully trained by the company that supplied the system and the materials. A ‘CWCT Installer’s Card’ is also available through the CWCT training programme.

CWCT run a range of training programmes for installers. They also provide training for main contractors, engineers, architects, and on-site supervisors. The CWCT recommends using a Specialist Contractor for the construction of the building envelope. This will help to meet the required standards in the tests for:

• Air leakage
• Thermal performance
• Watertightness

CWCT Specialist Contractors

Employing a Specialist Contractor for the design and construction of the building envelope will ensure that a project is completed on time and to the required standard. Specialist
Contractors are responsible for overseeing the design of the installation project and will consider all component sizes, tolerances, materials, and configurations.

A Specialist Contractor may carry out the installation themselves or they may employ a qualified sub-contractor. In either case, the Specialist Contractor or sub-contractor should be conversant with all the materials and systems and hold a CWCT Installer’s Card.

Installation guidance and essential industry knowledge

The CWCT has created a training course that comprises offering installer training by system designers. Working in conjunction with various systems houses, the training schemes provide both general installer information and specific product knowledge. A competent installer should already have some experience in the glass and glazing industry including knowledge of gaskets, sealants, hardware, glass, and glazing. These topics are covered in the training courses alongside information on specific system assembly involving joint assembly, allocating proper drainage and correct bracket installation.

CWCT also run a course called ‘Managing the cladding package’. This course is designed for main contractors, architects, and Specialist Contractors. It provides detailed guidance of how to oversee a glazing and cladding installation project placing particular emphasis on the importance of good planning and creating detailed drawings during the design phase.

CWCT training

Large scale cladding and glazing projects require industry expertise if the project is to run smoothly and be completed to a high standard within a certain time scale. Many cladding and curtain walling installation projects fail to meet the required industry standards due to poor workmanship which results in missed deadlines and additional costs through remedial work. Therefore, using fully trained and approved installers can greatly improve the overall quality of a building project.

To date, over 1500 installers have been trained under a CWCT scheme by a range of major curtain walling system suppliers. To ensure that your installation project is a complete success, it is a good idea to specify that a proportion of installers working on a project are trained under a CWCT scheme. It is also good practice to have someone on site in a supervisory role who has also received CWCT training.

CWCT site testing

Site testing is an essential way to ensure that a glazing installation project meets the desired standards. Tests should be carried out both early in the project to assess if any remedial work is required and upon completion of the project to check for compliance with industry standards. CWCT site testing specialists provide a thorough service which seeks to promote high standards across the construction industry.

The three main areas for testing under CWCT criteria are:

• Air leakage testing – Whole building air leakage testing in line with Part L of Building Regulations.
• Water penetration testing – On-site workmanship testing is carried out by hose testing. Designs are tested by improvised cabinet tests or spray bar tests.
• Thermal performance – Thermal imaging is used to identify any thermal bridges where air may leak from the building interior. Surface temperatures are measured to provide information on thermography and what can be done to address any problems.

At Exlabesa, all our aluminium curtain walling systems are CWCT certified. They have undergone rigorous testing to ensure that they meet all the essential industry standards.

If you’re involved in a glazing or cladding installation project and you’d like to find out more about working with Exlabesa, get in touch today. You can call us on 01302 762 500 or send us a message online and we’ll get back to you as quickly as possible.