Know-how | CW-FS | Perimeter Barriers and Firestops for Curtain Walling | Façades | Products | Siderise

Siderise CW-FS | Perimeter Barriers and Firestops for Curtain Walling – Know-how


Where do I access Test certifications?

Siderise are strong advocates of large-scale system testing and have participated in a significant number of such tests (including BS 8414, NFPA 285). This has provided considerable data which is invaluable in determining the performance of our cavity barriers.

Please see the systems test page for further information.

As the market leader in passive fire protection products, Siderise are also able to offer a wide range of Third Party Certified products.

These Third Party Certificates provide details of product testing and performance.

Siderise CW range - Perimeter barriers and fire stops for curtain walling 
Siderise RH - Cavity barriers for Ventilated Cladding/Rainscreen - Horizontal
Siderise RV - Cavity barriers for Ventilated Cladding/Rainscreen - Vertical
Siderise EW - Cavity barriers & fire stops for masonry external walls
Siderise LGS - Linear Gap Seal
Siderise RF - Cavity barriers and firestops for raised access floors 

Test Certificates for the RH and RV range are available from the product page.

What are National Classes (BS) and European Classes (EN) for reaction to fire and fire resistance?

Reaction to fire

National Class: Historically products were tested to BS 476-6 and 7 and then classified as Class 0, Class 1 etc. dependant on their performance.

Reaction to fire national classes have now been removed from Approved Document B for England & Wales (2019 edition).

European Class: Products should now be classified to European Class A1, A2 etc. under EN 13501-1.

Resistance to fire

National Class: BS 476-20 is a furnace test to prove fire resistance performance in terms of integrity (E) and insulation (I) in minutes.

For example, a product may achieve 120 minutes integrity and 90 minutes insulation.

European Class: Products should be tested to the relevant EN standard such as EN 1364-4 or EN 1366-4. The fire resistance in terms of integrity and insulation is then classified to EN 13501-2.

For example, a product may achieve 120 minutes integrity (E 120) and 90 minutes insulation (I 90), this would receive a classification of EI 90.

Approved Document B for England & Wales (2019 edition) now lists classification to EN 13501-2 as the primary route to compliance. BS 476-20 is listed as an alternate route to compliance.

UK coastal locations, weather exposure zones & product durability

Please see the following advice from Premier Guarantee:

Chapter 13 of the Premier Guarantee Technical Manual refers to Developments within 500m/5km of the coastline requiring additional consideration to the effects of a more detrimental site exposure, compared to other parts of the country.

That exposure can be due to the following environmental factors:

  • Wind driven rain from offshore.
  • High winds coming in land from the sea with no shelter from hills other buildings.
  • Corrosive effects from the saline rich wind driven rain – again from offshore.
  • Wind driven sand – clogging up balcony and other rainwater outlets.
  • Higher levels of UV which can effect finishes.

The ‘Functional Requirements’ specifically differentiate between:

  • Developments within 500m of the shoreline; requiring the design team to provide specific information to prove the durability, suitability and weather tightness as well as planned maintenance to be provided.
  • Developments within 500m – 5KM of the shoreline; requiring the design team to prove that the protection provided against the effects of corrosion and reduced durability are appropriate and suitable for the location.

The guidance that then follows provides a suggested solution to meeting the Functional Requirements.

Chapter 13 of our Technical Manual is currently under review and an issue that commonly needs clarification is that of:

‘How do we define Exposure correctly for a given site?’

The answer is: “A combination of one or more of the above bullet points, all identify for Warranty purposes, that a coastal location represents a higher environmental risk than a non ‘coastal location’.”

The guidance in is to be updated, as the current reference to ‘rain penetration’ in coastal locations is stated ‘deemed to be very severe’. Whilst this is true on many coastal locations, the Wind Driven Rain Map (Figure 1 Chapter 13, below) will show some coastal locations to be a lessor exposure to wind driven rain e.g. Southend on Sea or ‘Moderate’ Ramsgate, Whitby or Aberdeen.


Rain Driven Wind Map

Figure 1: Map showing exposure to wind-driven rain categories

The issue here is that although the Wind Driven Rain Map is a useful guide to the exposure to ‘wind driven rain’, it is not a method to determine the level of environmental exposure for the other factors, such as:

  • High winds coming in land from the sea, with no shelter from hills or other buildings.
  • Corrosive effects from the saline rich wind driven rain – again from offshore.
  • Wind driven sand clogging up balconies and other rainwater outlets.
  • Higher levels of UV, which can effect finishes.

Even using the more accurate guidance in BS 8104 - ‘Assessing the Exposure of Walls to Wind Driven Rain’ - will still only determine a site exposure to wind driven rain.

Both the Map and BS8104 don’t take into account the other factors, such as levels of UV or levels of saline in the rain. Therefore, they should not be used as a reference to accepting potentially lower levels of corrosion protection to exposed steels, or for coatings to finishes having a lower standard or not requiring more regular maintenance.


Where a development is within 5km of the shoreline, the construction is considered to be exposed to aggressive environmental issues, causing the durability of materials in these locations to be at more risk.

Reference to exposure maps for ‘wind driven rain’ should not be used to identify exposure to all the environmental factors associated with a Coastal location.

Sub note regarding identifying sites for Wind Driven Rain:

BS 8104 is a very useful tool for identifying exposure to wind driven rain in the following examples:

  • A number of sites shown within a coastal location and on the Wind Driven Rain Map appear to be in a ‘Very Severe’ Exposure Zone, have actually been proven using the more accurate method in BS 8104 to be in a moderate location (due to shelter from the landscape/orientation, etc.) This however only tells us that perhaps a checked rebate to the window and door openings are not required, or larger overhangs at verges/eaves may not be required.
  • In-land sites such as a regional or local airports, located in open raised locations, can be, according to the Wind Driven Rain Map, in a Moderate area, but according to BS 8104 and ‘local experience’, could in fact be in a more exposed location.

The above information has been taken from Premier Guarantee (link).

With respect to Siderise products we would recommend that when used in exposed conditions with high saline content that stainless steel fixing brackets are used.

For further advice, please contact Technical Services.


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