Residents received letters and people have to fit Intumescent strips to doors. Not sure if I should go with just intumescent or go with smoke seal too?
A cold smoke seal ("brush strip") will inhibit the movement of smoke round the edges of a closed door. Intumescent seals alone won't do this because they only work at high temperatures. They (brush strips) can, however, make it more difficult to close the door without making adjustments to it (planing-in). On the plus side they reduce draughts and noise transmission considerably (adding a drop seal to the bottom of the door further helps)
Do these fit to the frame or the door
In retro fits it is far easier to remove the door from the frame/casing and rout around 3 edges (two sides and the top). The job just cannot be done with the door hung in place. Note that strips alone do not make any old door into a fire door
How should I do the job? Is there a simple way to make to make the 4mm groove?
The simplest approach is to use an intumescent strip cutter which will produce a consistent groove of the correct depth to take the strip. The strips are self-adhesive, although on some jobs (e.g. universities, hospitals, etc) we are instructed to additionally pin them (panel pins) at 300mm centres. These cutters are available for
1/4in routers and for
1/2in routers. Make sure that you get a cutter for the correct width of groove - intumescent strips in the UK are generally 10, 15 or 20mm wide. An acceptable alternative (at least some listed buildings) might be a surface-mounted intumescent seal kit such as
these from SafeLincs. These are generally restricted to 30 minutes only, however. May be worth asking about whether the building owners approve same
Also, they mention something about hinges meeting BS......
Yes, on a fire door the hinges will need to be
class 10 or higher fire rated (depending on door load, fire rating, etc). That generally means a 4in/100mm stainless steel or brass hinge, most often fitted with ball bearing knuckles. The hinges should be mounted onto
intumescent pads as well. In addition on 1 hour doors any ironmongery which pierces the door (e.g. mortise locks, etc) is supposed to be protected by wrapping in intumescent paper, etc
Surely nobody should be asking this question after events such as Grenfell?
One of the points about fire-proofing is that it isn't just a case of installing hew seals and hinges. The gap around three sides of the door (top and two sides) must be checked (and if needs be adjusted) to be between 2 and 4mm - below 2mm and the door generally won't close properly, above 4mm and the seal won't give you sufficient sealing in the case of a fire. I generally use a taper gauge and brake calliper feelers to do this. The gap at the bottom is somewhat different, and many doors have far too big a gap. The rule on 1 hour fire doors, for example, is that the gap must not exceed 4mm between the floor and the bottom of the door across the entire width. If it does it needs to be dealt with by installing a fire-rated drop seal (surface-mounted or routed-in to a groove across the bottom of the door). Then there's the door itself - is it a proper fire-rated door (generally indicated by either a sticker on top or coloured rating plugs in hinge edge) and of the appropriate rating for the door oepning? (Doors between flats and communal stairways generally have to be 1 hour rated). And one other thing - most fire doors need to be fitted with an appropriate door closer to be compliant. And I haven't even got onto door frames/casings, packings, etc
There is now a big push to ensure that doors in public buildings and buildings with communal areas meet the fire requirements. Current legislation is basically embodied in the Regulatory Reform (Fire Safety) Order 2005 (RRFSO). Note the date - 2005. Personally, as a working joiner, I am appalled at how few joiners, especially the one-man bands out there, are still unaware of this legislation and how to apply it (based on how many defective/non-compliant doors I see in the real world). Want some more interesting reading? Then
this will hopefully clarify the points I am trying to make
