Fire Doors - Intumescent strips

[numpty]

Can someone please explain how hard it it to open a door where the intumescent strip has expanded to seal the door? Reason I ask, is it acceptable to have a door on a fire escape that has an intumescent strip, as it could prevent someone from opening it.
Thinking of a corridor separating door or a door in a fire wall which is also on the escape route.

[Slash hose]

If the intumescent strip has expanded due to heat you wouldn?t want to open the door! The conditions on the other side would be untenable! Not that you?d be able to get near to it as there would still be smoke on the non-fire side and the door handle would probe too hot up touch.

[numpty]

You might be a firefighter wanting to enter a room or get down the corridor.
If the people in the building evacuate as soon as the alarm goes off, Why need intumescent strips? It cannot be enforced by fire because it?s life risks and everyone would be out the building.
It might stop a fire damaging another area but that?s for insurance not life protection.

[Messy]

Numpty - Intumescent seals  can most certainly be a life safety control measure in bulldogs small and large

Examples

A single staircase 4 storey hotel with bedrooms or other rooms opening onto the stairs. It may be necessary to ensure the doors onto the staircase (which may be escape doors from the bedrooms) are resilient and hold back fire a sufficient time for those sleeping above to be woken and start their evacuation past the room which is alight

A hospital with progressive horizontal evacuation or an office block with phased evacuation. Both examples will require relevant persons to stay in the building after the fire has been discovered . Ensuring fire compartments are tight is an essential part of this strategy

Then there is basement fires, plant rooms at other high risk locations on or near to an escape route...... etc

So to assume seals are just for building protection is rather a simplistic viewpoint

[numpty]

Messy - I fully understand that they are simply not for building protection and value the importance of protecting the escape route. My question was how tight would they hold a door once the strip has activated, I have seen these strips on cross corridor fire doors, which got me thinking how would someone open one of they needed to pass it, this would include fire fighters that might enter the building.

[AnthonyB]

Doors without intumescent strips and just 25mm stops were found in experiments during the 80's to suffer from pyrolysis of the door edges creating substantial thick heavy smoke that layered under corridor detectors so they wouldn't trigger. This led in part to the 1988 revision of BS5839 introducing Life safety & Property protection detection categories with the minimum life cover being detectors in rooms opening onto escape routes as the escape routes (escape route only cover being the usual before then)

This in part is no doubt why intumescent strips became standard as well as cold smoke seals, as whilst the traditional doors gave a reasonable degree of protection they were a long way from perfect (see the test videos on Youtube showing a fire doorset without seals next to one with them, lots of smoke and hot gases around the edges from relatively early on).

As has been said for an intumescent to fully activate the conditions on at least one side are usually lethal and you wouldn't want to open it. Even firefighter's have to proceed with care as even with PPE & RPE they aren't invulnerable, especially for exposure to extreme heat for any length of time, nor from backdraughts by randomly opening doors.

If the drawbacks outweighed the benefits we've had over 30 years to find this out and I've not heard any serious objections.

[lyledunn]

Equally important is the smoke seal. I was on site in a relatively new sports club building when a small fire in a service room operated the fire alarm. I went with the caretaker to investigate and carefully opened the door. We decided to leave the fire fighting to the professionals. With the door closed, it only took a couple of minutes before the corridor onto which the service room joined, was filled with choking smoke.