Norsound NOR755 Retro Fit Door Head & Jamb Door Seal

Norsound NOR755 Retro Fit Door Head & Jamb Seal | Aluminium | Silicone Bubble Gasket | 5 × 26.5mm

The NOR755 is a screw-fixed head and jamb seal designed for retrofit installation around the perimeter of doorsets to provide acoustic sealing and draught exclusion at the door head and jambs. The seal uses an ultra-soft silicone bubble gasket that compresses against the door face when the door closes, forming a continuous seal around the door perimeter. The silicone bubble profile provides a high degree of compliance, accommodating minor variations in door face geometry and ensuring consistent contact across the full length of the seal. The NOR755 is fixed to the door frame stop and does not require modification to the door leaf.

The NOR755 is manufactured from aluminium with a silicone gasket, supplied in satin silver with a grey gasket. The housing profile is 5 × 26.5mm. Available in two standard lengths — 1000mm and 2100mm — to suit head and jamb applications respectively, or to be cut to length on site. Acoustically tested in accordance with BS EN ISO 10140-2. Suitable for use on standard fire doors to assist compliance with Approved Document E.

Applications

• Door head and jamb sealing on acoustic doorsets — fix to the door frame stop at the head and both jambs to create a continuous perimeter seal around the door leaf. The silicone bubble gasket compresses against the door face on closing, sealing the gap between the door leaf and the frame stop. Used in conjunction with a compatible door bottom seal (NOR815, NOR820, or NOR855), the NOR755 completes the acoustic barrier around the full doorset perimeter.
• Retrofit upgrade to standard fire doors — the NOR755 is fixed to the frame stop and does not require modification to the door leaf or frame rebate, making it suitable for retrofit installation on existing doorsets. The screw-fixed aluminium housing is compatible with timber frame stops on standard fire doorsets.
• Approved Document E compliance assistance — when installed as part of a correctly specified doorset assembly with a compatible door bottom seal and threshold, the NOR755 can assist in achieving compliance with Approved Document E requirements for airborne sound insulation through doors.

Product Benefits

• Ultra-soft silicone bubble gasket — high compliance, consistent contact. The silicone bubble profile compresses readily against the door face, accommodating minor variations in door face flatness and frame geometry. Silicone maintains its elastic properties over a wide temperature range and does not harden or crack over time, providing consistent sealing performance throughout the service life of the seal.
• Screw-fixed to frame stop — no door leaf modification required. The NOR755 is fixed to the door frame stop, leaving the door leaf unmodified. This makes it straightforward to retrofit to existing doorsets and preserves the fire resistance certification of the door leaf.
• Acoustic tested to BS EN ISO 10140-2. Tested in accordance with BS EN ISO 10140-2, confirming acoustic sealing performance at the door perimeter.
• Two standard lengths — 1000mm and 2100mm. The 1000mm length is suited to head applications on standard door widths; the 2100mm length covers standard door height jamb applications. Both lengths can be cut to size on site.
• Low-profile 5 × 26.5mm aluminium housing. The compact housing profile adds minimal build-up to the frame stop face, maintaining door clearances and preserving the visual profile of the doorset.

Installation

Measure the door head and jamb dimensions and select the appropriate lengths. Cut to size on site if required.

Position the NOR755 on the face of the door frame stop at the head and both jambs, with the silicone bubble gasket facing the door leaf. The gasket should be positioned to make contact with the door face across its full length when the door is in the closed position. Mark and drill fixing holes. Screw-fix the housing to the frame stop at regular intervals.

Close the door and check that the silicone bubble compresses evenly against the door face along the full length of the seal at the head and both jambs. Adjust the fixing position if required to achieve consistent contact. Ensure the seal does not impede the door from closing fully or engaging the latch.

Install a compatible door bottom seal (NOR815, NOR820, or NOR855) and threshold to complete the acoustic barrier around the full doorset perimeter.

The Technical Details