14.03 Suppliers

Categories: Procurement

Introduction
There are many suppliers involved in the procurement and supply of a facade.  There are principal suppliers such as the aluminum and plastic system companies, panel and glass suppliers. A second tier of companies supplies components including hardware, sealants, gaskets, finishes and so on.  The supply chain is dominated by the principal suppliers and the type of construction.  For instance the use of an aluminium stick wall rather than one made from pvc-u will determine the hardware available.  Many suppliers regard the domestic and commercial markets for windows as completely differentiated markets for their products.  The supply chain is best viewed from the perspective of which contractor purchases the components and the role they play in selection.
 

Supply through a system company
A system company is primarily concerned with the supply of profiles made of aluminium, pvc-u, steel or a composite of these.  The aluminium and pvc-u system suppliers tend to concentrate on one material but there are companies who can supply both.  Steel systems suppliers only supply steel systems.  Composite profiles may be developed by companies working in any of the traditional sectors.

In addition to supplying profiles in bar lengths to fabricators, system suppliers will also buy in and supply to their fabricators; gaskets, sealants, hardware, fixings, brackets and vents.  Many also provide warranties that are dependent on the use of the correct components recommended and supplied by the system company.

Clearly the system companies set minimum standards for components that they supply to fabricators and there are handling costs.  Both of these factors add to the cost of the components used by a fabricator who may be tempted to substitute other cheaper components.  The system supplier will have tested components as part of testing its wall or window and substitution of components by the fabricator may well lessen the performance of the finished facade.
 

Supply to a system fabricator
A system fabricator buys supplies of two kinds in addition to purchasing the basic aluminium or pvc-u profiles.  These are the components that are integral to the system such as gaskets, internal seals and so forth.  Secondly there are those components that are not part of the system.  These include glass and infill panels, specialised hardware, flashing and interface materials.

As stated above system fabricators may be tempted to source components directly rather than deal through a system company.  However, the fabricator may not have full knowledge of how the system works or the performance requirements of components such as gaskets or a modified pressure cap.  Where companies do have this knowledge and test the components in the system then there is probably little risk arising from this approach to modifying a wall.

Fabricators are responsible for the whole performance of the wall and are purchasers of glass and infill panels.  These are fundamental to the overall performance of the wall in terms of appearance, thermal performance and acoustics.  The latest glasses deliver high thermal performance and give whole life savings and  glass can be the single most expensive element of a wall. Glass has a major impact on the cost of a facade.

Brackets and fixings are sometimes purchased from a system supplier but are normally manufactured by the fabricator or outsourced to a local company.  Not all system companies supply standard brackets and those that do report that sales are low in comparison to the amount of profile sold.

The fabricator is also reponsible for manufacturing all of the interface components.  These may include flashings, closures, parpapet covers and window pods in rainscreen.  The quality of these components is important to the overall quality of the wall and its appearance yet these components are drawn from a large number of small companies and the standard of materials depends on the specifications and quality systems of the fabricator.

The system fabricator will purchase sealants if they are the installer and may supply materials such as sealants to a sub-contract installer.
 

Supply to an integrated curtain wall company
A company that undertakes design and development of profiles and components as well as designing the wall in terms of layout, functionality and appearance.  Will be involved in the purchase of most components that are included in the finished wall.  The role of the curtain wall company is then a combination of the roles described above for a system company and one of their fabricators.

The distinctive aspect of supply to an integrated curtain wall company is the amount of knowledge available within the company.  They might then be expected to be better purchasers and of course there is no temptation to substitute components.  It should also be noted that the larger curtain wall companies are bigger small to medium UK main contractors and can justify buying departments that manage the supply chain.  However, like main contractors, not all curtain wall companies are doing this.
 

Supply to an installation company
An installation only sub-contractor plays a small role in purchasing of supplies and materials may be supplied as free issue from the system fabricator or curtain wall company.  However, purchase of sealants may be left to the installation company where of course there is a temptation to use cheap materials taht do not provide the full performance required.

Installation companies will also be involved in remedial works during the life of the contract.  For instance refinishing damaged metal surfaces.  It is at this stage that inappropriate materials are most likely to be purchased by the installation company.
 

Continuity of supply
The use of a small number of suppliers by say a system fabricator would simplify the procurement process and would ensure that known products and suppliers were used.  Unfortunately this is seldom possible on many curtain walling contracts.  Changes to the performance requirements from wall to wall mean that a different product is required on a contract.  For instance an acoustic window or a particular paint finish or stone.  This may have a knock on effect if for example the choice of a particular stone requires the use of a different type of sealant.  It is therefore seldom that a wall is built using exactly the same supply chain as for a previous wall.  This is best managed with techniques such as FMEA, Section 14.05.