Fire protection of cladding systems in non-combustible and non-combustible construction - A Panel Discussion

The risk of involvement of cladding in non-combustible construction has long been an issue culminating in the advent of  Exterior Insulation and Finish Systems (EIFS) in the 1980s and 90s. The development of the CAN ULC S- 134 test method for use in non-combustible construction enabled representation of the typical scale of exterior fires and is generally indicative of the potential hazard arising from cladding in non-combustible construction. This is an expensive test which is difficult to pass without experience in fire testing and potential environmental conditions at the time of the test. New codes require an increasing use of high performance R Value envelopes which may introduce risks to fire of these envelope systems.

The use of the S-134 complying systems in combustible construction has raised a number of issues. While the use of S-134 systems will not add significantly to the fire spread arising from the cladding itself, the use of wood frame construction on the wood framing side of the cladding is not part of the S-134 test and no assembly is likely to pass the S-134 test due to disproportionate contribution from combustible framing and related materials.

Greater insulation targets and thermal bridging concerns are introducing plastic insulation as an option.  The use of building materials such as foamed plastic in both wood framed wall systems as well as non-combustible buildings may be a concern if combustible concealed spaces are created in ceiling and wall systems.  Downstream impacts include concerns about future building changes and impacts to the building sprinkler design.  In certain instances the need for non-combustible cladding systems or ratings on exterior walls due to spatial separation may also be a concern.

While the use of non-combustible wall systems or those meeting S-134 is not a concern in wood frame construction, there is a potential problem if the code requirements do not fully anticipate the combination of materials in  non-combustible or wood frame construction today.

 In terms of fire performance,  the fire protection engineer has the potential to assess the potential hazard posed by the disposition of combustible materials in a building envelope. This goes beyond the actual code requirements which may not have fully anticipated the degree to which building envelope and other issues would introduce new hazards requiring a more holistic fire risk assessment of these systems.

If nothing else, the recent Grenville Tower fire in the UK and similar fires in the Middle East highlight the need for a systemic analysis of fire safety in this kind of context.

While the fire risks of non-combustible construction and fire tests relative to facades are well understood, there needs to be a rethink of the other risks that we may be introducing that could create problems in construction relative to fire and life safety.

PANEL DISCUSSION FEATURING:

Moderator: Bob Heikkila

Tavis McAuley - Thorson McAuley Consultants
Martina Soederlund - reLoad Sustainable Design Inc
Kyle Koke and Kal Kooner - Intertek 
Carlos Gatti – Keith Panel Systems
Bill May - Protection Engineering

Date:  April 3, 2018
Time: Registration and Reception 5:30pm
Location: False Creek Yacht Club (1661 Granville Street)
Cost: Members - $35; Non-members $40. Please bring cash or a cheque payable to BC Society of Fire Protection Engineers to cover the cost of dinner.
Registration Deadline: March 31, 2018

Free parking is available in the Yacht Club parking lot.