The Building Regulations Blog

Solid core tight fitting doors are found in the buildings that possibly cause us the most concern for building permits

They provide our apartments with extra security. We used to think that they also provided us with some reasonable measure of safety from fire and smoke spread.  Maybe they don’t? This is relevant for everything from 2 to 4 storey apartment buildings. (And with alternative solutions maybe more!)

This debate has raged on for so long that we don’t remember when it started. We have gone back to a number of sources to revisit what has been said and see if a solution has been proposed.

We think this is a classic case of the solutions in the Deemed-to-Satisfy provisions not meeting the mandatory performance requirements. But they are deemed-to-comply!

The testing and the report commissioned from Warrington Fire Research (Exova) by the Victorian Building Commission (see below for more on this report) certainly thought so to:

“A “tight fitting” solid core door did not prevent the passage of smoke”

The final word from the industry has to go to John Rakic. John has been a passionate industry advocate in the area of passive fire protection. At Lorient, who was co-sponsor of the WFRA testing, he advocated for smoke seals and “life safety door” rather than solid core doors. In an extract in Infolink of his 2002 Fire Australia Article John says:

There is a possibly a serious misunderstanding in terms of the fire resistance and smoke leakage performance of a “tight fitting” solid core door and this door solution is not appropriate for life safety consideration, even in a sprinkler-controlled fire scenario.

Whilst John is not directly criticising the DTS provisions here – the comments are made in the context of alternative solutions that accept solid core “tight fitting doors” in lieu of fire door sets – he does ask – “Should a so-called “tight fitting” solid core door be in the BCA in the first place and why did it get there?”

The immediate solution seems to be smoke seals to the entry doors? This solution is by no means trouble free. Issues of concern include:

• The likelihood longer term of smoke seals being retained on the entry doors to residential apartments is considered low;
• The Essential Safety Measure maintenance requirements do not apply to the inside of apartments in apartment buildings.

John Rakic’’s key concerns from his paper above include

• Firstly, what is a “solid core” door? There is no definition in the BCA and there is no appropriate Australian Standard either. I have heard on many occasions that the timber door standards AS2688, AS2689 and AS1909 have definitions for “solid core doors” but they do not.
• Secondly, what is the definition of “tight fitting”? Again, there is no definition in the BCA for this term.
• A closer look at the rationale being applied by some fire safety engineering practitioners, is that there may be an incorrect or perceived performance for so called“tight fitting” solid core doors. They will not provide 20 or 30 minutes FRL and they will most certainly not provide tenable conditions in an adjacent corridor for the same period of time due to their so called“tight fitting” nature.
• Some fire safety engineering practitioners will argue that the spread of fire does not include spread of smoke and therefore will not include spread of smoke. They will therefore not include spread of smoke in their analyses and therefore will consider the omission of fire stopping products on penetration seals between adjacent sole-occupancy apartments and also allow the use of so called “tight fitting” solid core unit entry doors leading onto adjacent public corridors.

In the Australian Institute of Building Surveyor’s 2007 Conference where Paul England, MD of Exova in Aust, whoreported testing that showed the tight fitting solid core doors let through 16 times more smoke than certain doors with smoke seals. Paul advocates strongly for testing of doors with this function to AS1530.7 with exposure to 200 degrees C for at least 30 minutes. This criteria being the “performance criteria” in the DTS for smoke doors in Specification C3.4 of the BCA.

The Building Commission who part sponsored the Exova report said:

The project produced comprehensive results in relation to the spread of fire and smoke through a solid core timber door in a fire test. The results could be used to justify a performance-based design using the Building Code of Australia 1996.

(What we think the Building Commission might have been saying (?) was that) the research validated the use of at least smoke seals to apartment entry doors where fire doors were not required or omitted through an alternative solution.

A search of the Australian Building Codes Board website found nothing on “solid core doors” or “tight fitting” in this context. We would have thought at the publishers of the BCA that they might have had a view.  So we figure, in your 2, 3 maybe 4 level apartment building hopefull energy efficiency requirements to reduce infiltration and leakage by your front door might reduce the smoke spread in a fire!

Maybe we have been arguing the justification for seals to the entry doors the wrong way. The driver is about saving money and climate change not about people’s safety!

Tags: AS1530.7, Building Permits, smoke, smoke seals

This entry was posted on Saturday, October 16th, 2010 at 9:47 am and is filed under Alternative Solutions, BCA, DtS, Fire Safety, Smoke Hazard Management. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.