Life Expectancy Of Intumescent Strips

[BOB.BRIGHT@WMFS.NET]

Hi
I have recently been involved in a discussion on the life expectancy of intumescent strips in fire doors.
Obviously those that are worn, split or damaged are no longer effective to the degree required but I am informed that those in good repair do not necessarily have the life expectancy of the fire door in which they are installed.
My information is that intumescent strips that are carbon based have a longer life than those that are not but the ability of both to be effective to the degree required is reduced by the degradation of the chemical make up of the intumescent strip.
Does anyone have any knowledge on the validity of this statement?
Regards
Bob

[Mar62]

I dont have any specialist knowledge to that degree but I know of a company I sometimes call for advice. They are Sealmaster Tel: 01223 832851   Fax: 01223 837215

Email:
Sales: sales@sealmaster.co.uk
Technical Inquiries: tech@sealmaster.co.uk
Research: research@sealmaster.co.uk

[Davo]

Bob

Definitive answer assuming you don't know the make of the seals is ifsa.org.uk

davo

[MC]

I have previously aksed this question to a well know provider of intumescent strips , i was  informed that intumescent strips should have a life time expectancy of over twenty five years, the strips are capped off at each end to prevent water entering, this must be the silicone type, the example was many properties still have these strips installed and are over 25 years old. However i do not have this down in writing,

MC

[Davo]

MC

If you go on the ifsa site above, click on downloads, there is a 1997 document on this very subject.
Projected lifespans of 20 years were postulated after 12 years of monitoring .
Note graphite was excluded as they did not exist at the commencement of the study (1984)

I personally would change dependent on the observed state of the seals/brushes

davo