FD 20 fire doors

[Tom Sutton]

We have an existing dwelling that requires the existing 35mm solid core panel doors upgrading to FD20.

Are we likely to be able to upgrade the doors to FD20 with intumescent varnish?
Failing the above are you aware of any FD20 doors that are 35mm thick.
 
Your guidance would be very much appreciated.

[Fishy]

TRADA's fire safety 'arm', Chiltern International Fire, can probably give you a steer...

http://www.trada.co.uk/services/410235.html

Fishy

[Mr. P]

Falling back on BS's 476 & 8202 pt 1&2 to ensure application of coatings in compliance with the way were done for the relevant tests.

[Auntie LIn]

Can I suggest you don't think about trying to upgrade by using an intumescent varnish?
Generally, those that work need a thick panel (say 18mm) to start with.   A further problem is that any paint/coating, like the paint on your sitting room door, is only as good as it is complete - and once the kids have driven trikes into it - or the messenger has grazed it with the post trolley etc you have a point of weakness.   A further consideration must be that for the finish to be effective it has to be applied at a certain thickness.   I realise that I'm a mere female (natural blonde by brainpower!) but I have yet to meet anyone who, on site, is capable of applying x litres of finish per y square metres of surface - or 18 micron thickness come to that!  

Reading through your posting again - do you mean that the panels are 35mm thick?  If so, you'll get 20 minutes out of them - it's just the rest of the door you need to worry about.
If you want some more help with this drop me an e-mail with more details and I'll do what I can to help.

[jokar]

I have just been to Chiltern for a day and have to say was impressed with what I saw.  The point of this is that we asked about varnises and the like and they were not happy about that as an approach as detailed by auntie Lin above.  Does the door need an upgrade, as they say all doors are fire doors, perhaps on an Risk assessed basis upgard the alarm system instead.

[kurnal]

I agree with the need for caution over varnishes but there is a place for them.
Sometimes, especially in heritage buildings there is little other choice. Workmanship and maintenance are critical as LIn says and of course its impossible to verify the thickness of the coatings. But I have seen some pretty convincing demonstrations and fire tests using these products- one Cambridge based manufacturer does free seminars on the subject  -  to the English Heritage spec.

And the easiest way to apply the varnish is by a calculation based on area covered by volume of varnish used.

If you measure out the right quantity of varnish  and still have some left after applying a coat then its too thin!