Introduction

This technical document provides additional guidance relating to how the Functional Requirements in the Technical Manual may be satisfied when proposing to use a off-site manufactured product or system as part of the structure or waterproof envelope of the building.

What products does this document refer to?

Off-site manufactured prefabricated false chimneys, dormer units, canopy’s and external mouldings such as feature corbelling products.

What are the warranty concerns?

Off-site manufactured prefabricated false chimneys, dormer units, canopy’s and external mouldings are being marketed, some with and some without third party product conformity accreditation. For those products and systems that do hold third party approval certificates, there is often no evidence of durability or weather resistance.

Also the installation of some of these products and systems on site have either been found to not follow the manufacturers approved design and installation recommendations, or there is little consideration to how the product interacts with the adjoining construction, particularly in respect to resisting weather resistance or movement.

This has led in some instances to water penetration through to the structure occurring which required remediation works necessary post completion.

Warranty stance

Incorrect design and installation of this type of product is considered to compromise the ability of the respective construction element into which they are built in meeting with the Functional Requirements and Performance Standards stipulated by the Technical Manual, notably those relating to product testing and certification, durability, weather resistance and structural performance.

What developers should action after reading this document?

For Warranty purposes, where such products / systems are to be used on our sites, Developers must ensure that they are clearly identified at the start of a project and a full specification, including the third party certification documentation, be made available to our Warranty surveyor for a site specific review prior to commencement.

Any proposed off-site manufactured product or system used as part of the structure or water proof envelope of the building must be appropriately tested and approved for their intended purpose. Developers should ensure that suppliers and manufacturers of all prefabricated glass fibre false chimneys, dormer units, canopy’s or external mouldings have a valid third party product approval issued by a UKAS (or European equivalent) product conformity accredited organisation which is accepted by us.

The valid third party product conformity approval shall clearly state:

• The name of the product and its intended scope of use.
• The service life of the product.
• What exposure and environmental conditions the product has been tested to, the extent and type of testing and the performance achieved.
• That the manufacture of the product / system has been carried out under a recognised quality management process.

The developers design team must review this information against the requirements of the Technical Manual before submitting to the Warranty provider – notably considering the aspects of expected service life, durability and weather resistance / exposure for the individual specific site they are intending to use them on.

All components used in manufacturing of the product / system should satisfy Appendix C of our Technical Manual. Where a product is used within 5km of the coastal shoreline anywhere in the UK, the product and any associated fixings used must be appropriately durable for the aggressive environmental conditions.

The developer should also ensure that site teams have appropriate installation methodology in place for the installation of these types of product. This information should be followed on-site by any installation teams, and must align with the manufacturer’s installation procedure details, as identified in the third party approval.

Site teams should also be able to demonstrate quality assurance procedures covering installation are in place and are able to demonstrate appropriate controls and checks are being undertaken.

These details should be made available to our Warranty surveyor upon request.

Transitional arrangements

In December 2023, a transition date was announced for manufacturers of the above, to have had identifiable products independently assessed and approved by a UKAS or European Product Conformity accredited organisation by 1^st June 2025. 

To allow further time for manufacturers to complete their certification applications with the various product conformity bodies, we have extended the deadline to 1^st July 2026. 

The extension is on condition that from the 1^st June 2025, these specific uncertified products on live or new sites will continue to be accepted, providing: 

1. Only the Manufacturers that already have a contract engagement in place with a UKAS or European ‘Product conformity’ Technical approval body are eligible to this transition arrangement, and; 
2. Those manufacturers must maintain membership of the ‘Construction Glass Fibre Manufacturers Association’ (CGFMA) to at least 1^st July 2026, and;
3. The CGFMA audit must continue to be in place for the Manufacturers identified products being assessed.  
4. Evidence of the above 3 conditions must be available upon request by our Warranty surveyors. 

Please note:

We do not undertake product acceptance. It is the responsibility of the project designer to ensure products are suitable for the intended purpose and meet the requirements of our technical manual. The manufacturer should engage a UKAS or European equivalent Product Conformity accredited organisation to have products technically assessed for the scope of intended use.  

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This technical document has been prepared by Premier Guarantee exclusively for the benefit of our registered customers. Its sole purpose is to provide guidance on the utilisation and interpretation of technical requirements pertinent to the warranty cover offered by Premier Guarantee. Please note that this document is not intended for circulation or use beyond the aforementioned purpose. The information presented herein is for general guidance only and does not constitute professional advice. Registered customers and any other party accessing this document are advised not to rely solely on the information contained within. Nothing in this document is intended to establish, nor should it be construed as creating, any contractual or legal obligations. In the event that any third party chooses to rely on the information provided, they do so entirely at their own risk. Premier Guarantee explicitly disclaims any duty of care or liability that may arise from the use of or reliance on this document by any third party, howsoever arising.   

Ref: TS-3671