Edge detailing & intumescent seals.
Hardwood lippings are generally applied to vertical door edges of most product ranges, although they can also be applied to top and bottom edges where required - for example where used externally. Timber species are usually selected to match veneers, as outlined in the doorset materials and finishes section. Lippings provide protection to the edge of the door. The Plasform range utilises a postformed edge detail which conceals hardwood lippings.

Details of door edges for various situations are illustrated below:

Edge detailing. 

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Intumescent & smoke seals.

Perimeter fire seals are essential to performance and form an integral part of the doorset fire rating, irrespective of stop size. There are three types available: intumescent, intumescent and smoke seal combined, and concealed intumescent. The first two systems incorporate exposed intumescent strips to the frame jambs and head as standard, whereas the concealed method houses the intumescent strips behind vertical door lippings but exposed on top – this provides 30 minutes fire resistance only.

Generally, exposed intumescents are 15mm x 4mm for 30 minute performance or 2 no 15mm x 4mm seals for 60 minutes. Intumescent colour can be selected from our standard colour range.
All necessary intumescent seals will be included to the frame as standard in order to achieve the stated performance. In the case of pairs of fire-rated doors, a combined intumescent and smoke seal will be incorporated at the meeting stile of the primary leaf corresponding with a plain intumescent in the secondary leaf.

Where doors only are being supplied, seals need to be specified precisely if required. If intumescents are to be fitted by others, they must comply with our fire certification requirements under the BWF CERTIFIRE data sheet or Trada Q-Mark schemes. 

To reduce friction and aid compliance with opening force requirements a PS01 compression seal is fitted in the stop to provide smoke protection in accordance with BS 476 Part 31.1, ‘Requirement for Cold Smoke Protection’, providing the gap at the bottom of the door does not exceed 3mm. If it does, an additional threshold seal will be required.


Thresholds may be needed for acoustic and smoke control applications to restrict below-door gaps, working in conjunction with appropriate door-mounted seals. Essential thresholds must be fixed parallel to the bottom of the door and may be screw-fixed directly to hard surfaces such as concrete or smooth vinyl.

For carpet or textured/profiled vinyl flooring, they can be fixed directly to floor screeds. Aluminium thresholds for acoustic purposes should be located on a hardwood packer (to suit the floor finish depth) with mastic to threshold/packer and packer/screed. Note: Intumescent detail may vary from that shown depending on performance and certification.

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