Hygienic cladding installation inevitably requires silicone applied to various joints between the cladding and adjoining surfaces – walls, ceilings or second fix items, for example.
As specialist Hygienic Cladding installers, Goss are often asked by clients:
When is the best time to apply the finishing silicone to joints?
We are also often asked, given it might not be possible to weld some items:
Why haven’t you siliconed the joints between the cladding and the walls and ceiling?
To ensure the highest quality finish, the process of applying silicone to the joints needs to be carefully considered. And most importantly, applied at the right stage of the build/fitout process.
In this article, we provide answers to the various dilemmas of when and where silicone should be used. We will also explain the reasoning behind the choice of application and timing.
Which joints need silicone?
In many cases, rooms that require hygienic wall cladding are not a uniform shape. Additionally, fittings are often boxed in to create hygienic environments. Therefore, adjacent surfaces and fittings often don’t form a simple joint. It is sometimes the case that non-standard and angled joints have to be siliconed. This invariably occurs more frequently on retrofit projects. Older buildings often feature uneven and irregular walls and interfaced surfaces that require cladding.
The extreme example below shows a boxed heating pipe. Thermoform 90° angles have been used as well as hot weld joints. The remaining internal corners must be finished with silicone as well as the external box joints to make a neat finish.
Why can’t all joints be hot welded?
Due to the methods used to apply a hot weld, the tool design is unable to perfectly apply the weld and cut the excess jointing compound from the surface in some instances. This would mean the joint weld would not form a suitable finish.
The following video explains how Altro recommend hot weld jointing Hygienic Cladding.
Is silicone hygienic?
The simple answer is yes, silicone can be hygienic. But not all silicones available are recommended for areas that require high levels of hygiene and regular cleaning. There are specific silicones that have been created for the use in clean rooms. These silicones provide a mould shield and antibacterial protection to ensure the area remains hygienic. These will be used in areas which require the highest levels of hygiene, such as hospitals or laboratories.
Hygienic cladding manufacturers including Altro and Trovex manufacture colour matching hygienic silicone which can be used with their hygienic cladding and wall protection systems.
For added peace of mind, the hygienic silicones used in these areas will adhere to the requirements sated in ISO 11600 F25LM and for the Bacterial resistance level stated in ISO 22196:2011 : Measurement of antibacterial activity on plastics and other non-porous surfaces.
There are also specific ‘clean room’ silicones available on the market.
Where should silicone be applied?
- Silicone should be applied when either thermoforming or hot welds are not able to be used.
- Silicone is also frequently applied around second fix items including light switches, light fittings and plug sockets.
- Silicone will be used between ceiling grids to hygienic walls and between hygienic cladding sheets and boxing joints that are not thermoformed.
The image below illustrates how to select the correct techniques to use to minimise silicone joints when installing hygienic cladding.
When should silicone be applied?
The application process must only be carried out once the area has been thoroughly cleaned and dried so as not to contaminate the fresh silicone with dust or other particles. This is usually the final phase of the build process, after all second fix is complete and the build cleaning takes place and also when the hygienic cladding has already been completed (and the cladding teams have long gone). This is why the silicone package isn’t, often, linked with the hygienic cladding package.
When should silicone not be applied?
The process of applying the silicone to the joint is mostly not carried out by the installer of the hygienic wall cladding. This is due to the area containing dust or debris from all the of activities still being carried out after the cladding has been installed.
Contaminants will adhere to fresh silicone before it dries and dramatically affect the levels of hygiene in the area.
It is also important not to apply any fresh silicone in wet / damp / high moisture environments as this will affect the silicone stability once dry.
Only after the area has been thoroughly cleaned and dried can a silicone contractor be brought in to apply the silicone joint sealant.
Hygienic silicone choices
There is a range of hygienic silicone available that can ensure the right choice is made to match the environment, these include:
- Trovex – Colour match silicone
- Altro – Colour match silicone
- Bioclad – Colour match silicone
- Standard high quality hygienic silicones
- Sector specific silicone products such as Sika Everflex Clean room silicone
Proprietary manufacturers such as Altro, Trovex, Bioclad and Construcion Specialities can be contacted to check recommendations for silicone products to be used with their systems.
Should you have hygienic coatings, hygienic cladding or wall protection enquiries please contact us on office@gosscoatings.co.uk.
