Fatalities as a result of missing smoke seals?

[Midland Retty]

In my opinion the use of intumescent strips in most scenarios will only be considered for building protection. In some cases they may also be used to support life safety too.

But in any case, for building protection, or otherwise, Ive rarely ever seen them activate, and Im guessing if you asked most fire professionals they would tell you the same thing.

Do they actually serve a credible purpose in real life, outside of the test labs?


(I await a very stiff talking to from Auntie Lin)!

[SamFIRT]

I too have very rarely seen intumescent strips activate and if they do it is usually at very high heat fires where the door is very badly damaged. Smoke seals on the other hand (or even 25mm stops) will prevent (reduce) a great deal of smoke (and other gas) spread.

[Tom Sutton]

I too have very rarely seen intumescent strips activate and if they do it is usually at very high heat fires where the door is very badly damaged.

Shirley that's the point when the fire reaches those high temperatures and begins to pass between the fire door and the frame that's when the intumescent strips activate and prevent the passage of flame for a further period of time which I claim to be about 10 mins.

[Davo]

Tom

Graphite Intumescent Strips activate at about 120 degrees C, Silica at about 180.
As has been said, the heat at the door face must be very high as of course you only have a 3mm gap between frame and door

A more important discussion would be the merits of brush against neoprene strip seals

davo

[Tom W]

I would say a more important discussion would be to campaign to the manufacturers to improve the reliability of the strips.

Im tempted to do some digging. It could be a great product but its not doing whats claimed.

If they are just designed to activate at very high temps surely we are just talking about property protection NOT life saftey. So why are so many FSOs and FRAs asking for them as standard?

It doesn't matter that they are cheap and easy to install, they are still not effective.

[The Colonel]

Davo
I am not a fan of the neoprene seals, I find numerous locations where they are damaged so easily and in many cases the occupier removes the damaged seal completely when they are hanging leaving the intumescent strip in place. Recently undertook a risk assessment on a new office that had only been occupied for two months and numerous neoprene seals were already damaged. The brush seals seem to be able to cope with rough edges and uneven surfaces far better and are not so easily damaged.

However what ever type of seal is used the door and frame must be installed correctly with even gaps that are small enough for the seals to be effective, all to often in new builds it would appear that who ever installs the door sets has not the first idea of what the seal is for. Many seem to think it is a draft strip at best. I undertook a risk assessment on a brand new block of flats where the occupants had not moved in yet and as luck would have it the housing officers had keys to the flats. We were all interested in the layout and finish of the flats which included a FD30s entrance door. However when the 1st entrance door was viewed from the inside the gaps were larger than specified and the brush seal ineffective. A number of other doors were sampled and the standard varied, the problems were highlighted in the finished FRA. The builders answer was building settlement and as their approved inspector had made no comment they would not rectify saying it was now a problem for the housing association.

Yes smoke seals can be effective but those that install or inspect must know what they are doing and be prepared to put things right.

[SamFIRT]

By comparing intumescent strips and neoprene seals (brushes) surely one is comparing apples with fish. They happen to be located in roughly the same place on a FD but they do very different jobs. The low temperature smoke seals protect from the passage of the products of fire in the incipient and growth stage (especially so if there is a smouldering fire). The intumescent strip will slow the spread of hot smoky gases once the fire is fully developed.
 

[wee brian]

Intumescent strips only really do their job when the door is hit by a fully developed fire. In a lot of situations, when we specify a fire door we really only need something solid in the hole. However there are times when the door needs to deliver and the strips can help both in terms of sealing the operating gap and (perhaps more importantly) help stop the door falling to bits.

The flexible seals can be very effective at reducing the amount of smoke that gets past the door (it's more than you might expect) but they can wear out. The best ones are those that are mounted on the door stop rather than on the edge of the door. These ones compress when the door is closed so they dont wear out as quickly.

I think Auntie lynne produce a guide whic showed the different types.

Are they necessary upgrades - its up to your risk assessment to decide.................

[AnthonyB]

I must agree that the brush type smoke seals seem to withstand everyday usage far more than the thin strips, which are often damaged or pulled off entirely.

I often require door upgrading from 25mm stops primarily to increase smoke control via brushes/strips, it's just coincidental that that means they get an intumescent upgrade as well due to most smoke seals being incorporated into a strip.

That isn't to say the intumescent isn't important, it can be of use to life safety where you aren't evacuating as quickly as normal, such as a building with refuges or phased evac or healthcare.

As usual enforcement isn't consistent I've seen plenty of premise with notices on them for various things but totally overlooking the fire doors of the rebate only type (they were in good condition)