Fire Doors - Glazing?

[Redone]

Try again with a bit more back ground...

I have a office building, 2 storey, spiral staircase at each end.  Spiral is 1.2m from building.  Final exits are located directly below the spiral walkway from the first floor.  Due to the 1.2 m, I requested fire doors on the final exits ground floor level below the walkways, this was spec'ed on the designers plans as submitted for approval.

I can find no indication on the doors or glazing, or anything in writing to confirm FR, just a call from the designer saying they are FR.  Double glazing units are fitted into the door set, not seen this before... Is it me?

[Gasmeter]

If it was me I would ask for a certificate stating that the doorset is BS476.

[Harry Dewick-Eisele]

You should see a sticker at the top of the doorleaf stating the rating (probably FD30) if the door was manufactured by an approved fire door manufacturer. Glazing is not in contradiction to fire rating, although the size and number of panes is restricted.

[Fishy]

You should see a sticker at the top of the doorleaf stating the rating (probably FD30) if the door was manufactured by an approved fire door manufacturer. Glazing is not in contradiction to fire rating, although the size and number of panes is restricted.

Not all fire resisting doorsets have stickers; some use plastic plugs, and some have no indication at all!  

Demand to see the evidence of fire resistance performance for the doorset(s), and make sure that the double glazing is specifically mentioned.  Appendix A of the Approved Document B (assuming you're in England and Wales) gives an idea of what you should be looking for - test certification or independent assessment.

It's by no means impossible to make double glazing fire resisting, but it would take some specialist expertise on the door manufacturer's part.  If they have that expertise it follows that they should be able to come up with the relevant evidence pretty straightforwardly.  If they can't I'd be willing to make a reasonably large wager that they have been caught out, and the client ain't got what he's paid for.

[Redone]

Cheers for the replies folks.

No indication on the glazing or door frame.  The door is identical to that installed on the first floor exit where F/R is not required?

I'm told the relevant written confirmation is in the post...  Postie a bit slow.

[saddlers]

Why ever did we complicate the coloured plug solution on the edges of doors!!! It worked perfectly well and what little confusion it did create (painted doors etc) was surely less than is created by the stickered approach!!!!

[Redone]

The door has a single full size pane...

[kurnal]

Is it fire resisting glazing- should be etched as pyro or similar  or georgian wired, and mounted in an intumescent glazing system.

[Martin Burford]

Redone
Get the certificate from the door set testing centre, which I have done, for confirmation recently.
Conqueror

[Auntie LIn]

Hi Chaps

It's not common to find double glazed units in fire doors - in fact, in all my centuries of dealings with fire doors I don't ever recall seeing proof of one.

Always ask for test evidence - and know what you're looking for.   A test at full scale (which actually passes) or a proper assessment.

[Uncle Dave]

A little general information regarding double glazing and fire.

Assuming the glass is not insulating, the fire performance is partially due to the glass shedding heat to the non fire exposed side (I'm talking single glazing here).  When you have a double glazed unit the fire exposed side glass can not shed heat effectively because of the second pane.  This results in the glass pane on the fire exposed side failing early, leaving the outer pane to do the job on its own.  So, double glazing on fire resistant glass doesn't do a lot, it is the equivalent of single glazing.  Note, the detailing of the glazing must be satisfactory (tested or assessed).

I'm basing this post on a fire resistance test on a double glazed unit I did many years ago.  I can't remember any more than what I have posted.

Dave