First of all, please do remember that adding a fire seal to any door doesn't automatically make it a fire door. Do make sure that you have a properly tested fire door construction.

Also, please remember that not all fire doors are the same - so there's no single answer to this question.

What size/type of strip should I use to achieve 30/60 minute fire rating

The first thing to check is the door manufacturer's test evidence for the door you have - whatever type and size (or sizes) of seal they have tested with is what you should buy and the easiest way to ensure that the fire door complies is to adopt this simple rule

Intumescent fireseals should be fitted to appropriately tested and approved fire door assemblies in accordance with the door manufacturers fire test report.

The report will advise what type, size and how the seals were fitted during the test.

The manufacturers of intumescent strips advise that 

1. The door manufactures fire test results are consulted to check that the correct size and type of seal is being fitted.

2. Intumescent strips should be fitted into a groove of suitable width and depth to ensure that the pvc or aluminium holder is flush with its surroundings. (If seals are to be fitted at a later stage it is recommended that allowance in the rebate width/depth be made to allow for timber shrinkage, manufacturing tolerances and/or for the use of paints/stains).  

3. The recommended gap between door/door and door/frame is no more than 4mm. 

4. When using strips with a self-adhesive backing tape, ensure that the seal is pushed firmly into position along its full length.  It is important to ensure that the contact surface of the grove is dry and free of dust and grease that may impair the bond.  If there is any doubt we would recommend that the seal be either glued or pinned in position. 

5. If the door or frame is to be painted/stained care should be taken to ensure that the paint/stain does not come into contact with the brush pile on combined fire & smoke seals. 

6. In addition to the fitting of intumescent fireseals consideration must be given to the ironmongery, any glazed vision panels and around the door/window frame perimeter. 

Protection to these areas can be provided by the use of ~ intumescent mastic - intumescent/fire rated glazing seals - threshold seal cladding kits - hinge, lock & door closer protection products - intumescent letterbox liners/systems - smoke control products ~ further details on these products is available on request.

Also see BWF Fire Door Seals Fact Card (530kb pdf)

Pyro-Seal is a registered trademark of Wessex Intumescent Supplies Ltd.
WIS Multiseal-It and WIS Draught Stoppers are trademarks of Wessex Intumescent Supplies Ltd.
All other trademarks are acknowledged.

All goods sold or offered are subject to our terms and conditions of sale - copies available on request