by FlameContain » March 25th, 2009, 11:24 pm
I would reccomend that the fitting of the intumescent seals for existing doors should be carried out by a competent person although I don't believe that a formal qualification exists for such a person, this type of work is often carried out by carpenters. It is important to ensure that the seals have been successfully tested to BS 476 Part 22 and that they are fitted correctly after all it is a life safety requirement for fire doors to have intumescent strip to seal the gap around the door. A 30 minute fire door can be breached by fire within minutes if the gap is not sealed. As for certification of the door that depends on why you are fitting the intumescent - routine maintenance, refurbishment, upgrading the door etc. let me know why you are carrying out the work, what type of building it is and I should be able to tell you whether you need a certificate.
If you are fitting intumescent strips to an existing door there are a number of factors you should take into account the first is to determine the fire rating of the door, a timber door is usually rated at 30 or 60 minutes. A simple method of determining the rating where no label is visible on the door is to measure the door thickness, 44mm for FD30 and 55mm for a 60 minute door. You should fit seals with a fire integrity rating to suit the door i.e a 30 minute or 60 minute strip. A 30 minute strip will usually measure 10 x 4mm or 15 x 4mm and for a 1 hour door the strip will normally measure 20 x 4mm. It is not uncommon for two half hour strips to be installed on a one hour door.
The next step is to determine whether or not the door requires protection against the passage of smoke as well as fire, if smoke sealing is required then you should fit an intumescent strip with a smoke seal, this takes the form of a brush or rubber type fin built into the intumescent strip. Once a smoke seal has been fitted you should ensure that if the door is self closing i.e has a door closer fitted, that the door closes fully into the frame, often you will find that the door will not pass the smoke seal and fully latch, you should adjust the door closer accordingly to overcome the smoke seal.
The seals can be fitted into the door or frame and should be installed down each edge and across the top. It should also be noted that to fully comply with the requirements of BS 476 any ironmongery on the door should also be protected. This matter is often over looked. Hinges should have intumescent hinge pads or gasket fitted between each leaf of the hinge and the door and frame. Any lock case fitted to the door should also be wrapped in an intumescent gasket.
I hope I have answered your question, feel free to get back in touch if you need any clarification.
