Separate Cold Smoke Seal

[Bristolboy]

Hi

 

First post although I have used the forum as a resource in the past. We've got a number of HMOs, and they have all had fire doors fitted at various points (some by us, some prior to us buying the property). I understand the need for fire protection, especially in HMOs where occupants are far less likely to know if others are present in the property should the worst happen, but the combination of door closers and the usual cold smoke seals is a problem, namely that, for the brush to be effective it has to be in contact with the door, but it must not provide any significant resistance to stop the closer from closing the door without ratting the door off its hinges. The margin for error is so fine, and varies day to day depending on temperature of the room, temperature of the door, whether the window is open or not; one day a door will appear to be perfectly fitted and the closer perfectly adjusted, but the next day the door won't close fully or will slam shut.

 

Imo the usual practice of a combined intumescent strip with a smoke seal is poor; I'd much rather have a normal intumescent strip in the door or the frame as normal, and just the cold seal in the door stop so that the closer assisted door closes into the brushes. This would mean it's much easier to maintain a small gap between the door and the frame to increase the effectiveness of the intumescent strip, whilst at the same time increasing the likelihood of the cold seal being effective as the door will have closed onto it (and probably also benefiting from a reduction in the noise of the door being forcibly shut by the closer. Am I missing something as to why this isn't acceptable? I understand that fitting a combined strip can save time, but the tolerances are so fine, especially on natural substances that expand and contract, means that it's very difficult to always have closers and seals working effectively all the time. I'd rather have separate products and be confidence each is working as intended.

 

In an ideal world I'd like to be able to by a fire rated product along the lines of a self adhesive foam draught excluder (eg a self adhesive cold seal brush) but such a product doesn't exist. I have seen the Lorient Batwing and similar products but they aren't particularly cost effective. So, a couple of questions. Is it acceptable to remove the intumescent part of the combined seal to leave just the brush, and fit this in a rebated door stop? (I would still have an intumescent strip in the edge of the door or in the frame, but I don't like the idea of the strip potentially exerting a force to open the door. Or (secondly) am I overthinking this, and a combined strip is acceptable in the doorstop?). Thirdly, is it acceptable to remove the brush and attach that (eg with a staple gun) directly to the door stop? Finally, if I did this, would the remaining part still be acceptable as the intumescent strip (bearing in mind it would have an empty slit in it) or would I need to get a separate ordinary intumescent strip?

 

Sorry for the essay, many thanks in advance for any responses.

 

[Tom Sutton]

The problem is, no matter how you propose to prevent cold smoke passing a fire door and smoke logging the escape route, it has to be tested according to BS 476 Pt.31.1. All cold smoke seals that are on sale meet that minimum requirement and you must consider how you will fit them to the fire door. Batwing Seal would be one of the easiest because I think you could fit it and remove the brush seal, leaving the intumescent seal, without dismantling the door. The cost would be about £3 a length, less the £10 a door and I cannot see you getting it much cheaper no matter what solution you decide upon.

I cannot see removing the intumescent seal and leaving the brush seal will make any difference, as the intumescent seal lies flat with the door edge? A combined intumescent strip and brush seal is acceptable in the door rebate. If you remove the brush seal from the combined fire and smoke seal I cannot think it would be detrimental on the operation of the intumescent seal. 

Check out ASDMA Best Practice Guide I am sure this will help.

[Neil Ashdown MAFDI]

The Intumescent Fire Seals Association website at www.ifsa.org.uk provides information about various compliant options to meet the requirements. It also discusses the drawbacks and advantages of different types of seal.

[Bristolboy]

Many thanks for your replies, I've emailed IFSA so will be interested to hear what they come back with.

[Neil Ashdown MAFDI]

Hi Bristolboy,

Whilst waiting for a reply you could try the various documents here http://www.ifsa.org.uk/documents/ for advice.

Kind regards, Neil.