Norsound NOR720 Acoustic Perimeter Seal – 5 × 4.2mm × 2100mm is a compact kerf-fit TPE seal designed for use around smoke-control doorsets and at the meeting stiles of suitable acoustic doorsets.
The profile is inserted into a narrow groove machined into the edge of the door leaf or into a suitably prepared frame.
Once installed, only the flexible sealing blades remain exposed. These blades contact and overlap the opposing door stop, frame or adjoining door leaf to help restrict smoke, airborne sound, draughts and light through the operating gap.
Each NOR720 is supplied in a fixed 2100mm length and is available in:
Norseal specifies the NOR720 for:
The manufacturer’s fitting instructions also permit the profile to be used as a door-bottom seal when it closes against a suitable threshold plate and the gap beneath the door is between 7mm and 9mm.
The exact application must follow the evidence and specification for the complete doorset.
The NOR720 is significantly smaller than many face-fixed perimeter seals.
Its nominal profile dimensions are:
The retaining section is inserted into a narrow kerf or routed groove, leaving the flexible blades visible outside the door edge or frame.
This concealed fixing method provides:
The flexible TPE blades project from the kerf-fitted retaining section.
When the door closes, the blades overlap and deflect against the opposing door stop, frame or meeting-stile surface.
This helps close the normal operating gap without using a rigid compression block.
The profile can help restrict:
The blades should make consistent contact without becoming completely crushed or preventing the door from closing correctly.
Norseal’s fitting instructions specify that the NOR720 should overlap the door stop by approximately:
0.5mm to 1mm
This controlled overlap helps the flexible blades maintain contact when the door is closed.
Too little overlap may leave an open leakage path.
Excessive overlap may:
The seal position and groove depth should therefore be established carefully before the complete installation is carried out.
The NOR720 has been smoke tested in accordance with:
BS 476-31.1
When correctly installed around the head and jambs, the flexible blades help restrict cold smoke passing through the operating gap between the door and frame.
A complete smoke-control doorset may also require:
The NOR720 should not be treated as the only smoke-control component within the complete door assembly.
The NOR720 has been acoustically tested in accordance with:
BS EN ISO 10140-2
Norseal identifies the profile for use at the meeting stile of acoustic doorsets, where the gap between adjoining leaves can otherwise provide a direct path for airborne sound.
The individual seal does not have a universal standalone decibel rating.
Final acoustic performance depends on the complete tested door assembly, including:
Any numerical sound-reduction figure must be attributed to the complete tested doorset rather than to one length of NOR720.
The meeting stile is the vertical junction where two door leaves meet when a double doorset is closed.
Even a narrow untreated meeting-stile gap can allow significant sound and smoke leakage.
The NOR720 may be kerf-fitted into the edge of one or both leaves according to the tested doorset arrangement.
The profile should:
The active and inactive leaf sequence must continue to operate correctly after installation.
For smoke-control doorsets, the NOR720 can be installed around the head and vertical jambs.
The profile may be fitted into:
Where it is installed in the frame, Norseal states that the groove must be machined before the frame is installed.
The exact fitting position must reproduce the applicable smoke-test or doorset arrangement.
Norseal’s fitting instructions state that the NOR720 can be used as a door-bottom seal when combined with a threshold plate.
For this arrangement, the manufacturer specifies a gap between the floor and door bottom of:
7mm to 9mm
The threshold plate must provide a firm and continuous surface for the flexible blades.
This alternative application should be used only where it is compatible with the complete doorset specification.
An automatic drop seal may be more appropriate where:
The NOR720 is manufactured from TPE, or thermoplastic elastomer.
TPE provides:
The blades should be protected from paint, adhesive, deep cuts and permanent deformation.
The NOR720 is not self-adhesive.
It is retained mechanically within a narrow groove machined into the door or frame.
Norseal’s standard fitting instructions specify:
Where the operating gap is less than 3mm, the instructions permit a 5mm router cutter to be set to a suitable depth so the profile can be recessed sufficiently.
Norseal instructs that the seal ends should be cut at 45 degrees to create continuous sealing around the door.
Mitred corner joints help:
The profiles should meet closely without crushing or folding the flexible blades.
This product is available in:
Grey is not included within the manufacturer’s NOR720 colour range or the current stocked product range.
Colour affects the visible appearance of the seal but does not change its dimensions or performance classification.
Each seal in this product range is supplied in a fixed:
2100mm length
Norseal’s wider manufacturer range also includes a 3000mm option, together with other lengths available on application.
Only the 2100mm length is included within this product range.
The number of lengths required depends on the application.
For example:
Measure the complete doorset before calculating the required quantity.
The NOR720 and NOR710 use different fixing systems and are intended for different arrangements.
| Feature | NOR720 | NOR710 |
|---|---|---|
| Fixing | Kerf-fit | Self-adhesive surface fixing |
| Nominal profile | 5 × 4.2mm | 10 × 10.2mm |
| Material | TPE | Rigid and flexible PVC |
| Primary stated application | Smoke-control head and jambs or acoustic meeting stiles | Acoustic and smoke-control head and jambs |
| Machining required | Yes | No |
The products should not be substituted without checking the doorset evidence and intended sealing arrangement.
Suitable applications can include:
Before ordering, confirm:
Do not use the NOR720 to compensate for a warped door, misaligned leaves, loose hinges or excessive perimeter gaps.
Norsound NOR720 Acoustic Perimeter Seal is a kerf-fit TPE profile for suitable smoke-control door perimeters and acoustic meeting-stile arrangements.
| Product Name | Norsound NOR720 Acoustic Perimeter Seal – 5 × 4.2mm × 2100mm |
| Brand | Norsound by Norseal |
| Product Reference | NOR720 |
| Product Type | Kerf-fit acoustic and cold-smoke sealing profile |
| Primary Manufacturer Application | Around the head and jambs of smoke-control doorsets or at the meeting stile of acoustic doorsets |
| Alternative Application | May be used as a door-bottom seal with a suitable threshold plate where permitted |
| Fixing Method | Kerf-fit into a machined groove |
| Self-Adhesive | No |
| Mechanical Screws Required | No under the standard kerf-fit arrangement |
| Nominal Profile Size | 5 × 4.2mm |
| Flexible Blade Projection | 4.2mm nominal |
| Retaining Section Dimension Shown in Fitting Guide | Approximately 3.3mm |
| Material | TPE |
| Available Length | 2100mm |
| Manufacturer’s Wider Length Range | 2100mm and 3000mm, with other lengths available on application |
| Available Colours | Black, Brown and White |
| Grey Available? | No — Grey is not listed for the NOR720 |
| Smoke Test Standard | BS 476-31.1 |
| Acoustic Test Standard | BS EN ISO 10140-2 |
| Certifire Reference | Norseal currently lists CF629 |
| Standard Saw-Kerf Arrangement | 3mm-wide saw blade producing a groove approximately 4mm deep |
| Alternative Router Arrangement | A 5mm router cutter may be recessed to a suitable depth where the operating gap is less than 3mm |
| Door-Stop Overlap | Approximately 0.5mm to 1mm |
| Corner Joint | Ends cut at 45 degrees to maintain sealing continuity |
| Door-Bottom Gap with Threshold Plate | 7mm to 9mm under the manufacturer’s alternative bottom-seal arrangement |
| Intumescent Fire Seal | No — the NOR720 does not replace a required intumescent fire-door seal |
| Standalone Acoustic Rating? | No — performance depends on the complete tested door assembly |
| Standalone Fire Rating? | No — the NOR720 does not independently provide a fire-resistance period |
| Colour | Profile Size | Length | Product Code |
|---|---|---|---|
| Black | 5 × 4.2mm | 2100mm | NOR720/2100/BLK |
| Brown | 5 × 4.2mm | 2100mm | NOR720/2100/BRN |
| White | 5 × 4.2mm | 2100mm | NOR720/2100/WHT |
Norseal’s general order-code format is:
NOR720 / Length / Colour
For example:
The three codes shown above are also the exact stocked codes within the current supplied product range.
Norseal’s fitting guide instructs installers to use:
The profile is then pushed into the kerf.
The groove must be:
Do not widen the kerf unnecessarily, as an oversized groove may fail to retain the profile securely.
Where the gap between the door and frame is less than 3mm, Norseal permits a 5mm-wide router cutter to be set to a suitable depth.
This allows more of the profile to be recessed into the door or frame.
The required depth must be established by trial fitting so that:
The NOR720 has been smoke tested in accordance with BS 476-31.1.
Effective smoke sealing requires:
The seal should not be treated as the only smoke-control component within the complete doorset.
The NOR720 has been acoustically tested in accordance with BS EN ISO 10140-2.
No universal standalone decibel rating should be assigned to one profile.
Final acoustic performance depends on:
The NOR720 is a smoke and acoustic seal rather than an intumescent fire seal.
Where it is installed on a fire-resisting doorset:
Store the NOR720:
Inspect the NOR720 regularly as part of the door-maintenance programme.
Replace the correct profile where it is:
Do not replace the NOR720 with a self-adhesive or differently sized profile without confirming compatibility with the doorset specification.
Norsound NOR720 Acoustic Perimeter Seal is retained within a narrow kerf machined into a suitable timber door leaf or frame.
The exact seal position must follow the smoke-control or acoustic doorset specification.
Norseal’s standard installation uses a 3mm-wide saw blade to form a groove approximately 4mm deep. The seal should overlap the door stop by approximately 0.5mm to 1mm, and adjoining lengths should be mitred at 45 degrees.
Inspect the complete doorset.
Confirm that:
Correct warped doors, loose hinges, misaligned leaves and excessive gaps before installing the seal.
Identify whether the NOR720 will be installed:
The installation position and number of profiles must match the relevant doorset evidence.
Do not assume that the same detail applies to all three applications.
Before machining, establish the direction in which the flexible blades will face.
The blades must project towards the opposing sealing surface.
Depending on the application, this can be:
Mark the profile orientation so it remains consistent around the complete installation.
For door-leaf installation, remove the door from its hinges.
Lay it securely on its side and restrain it firmly, as instructed by Norseal.
Support the door across its full length to avoid movement or twisting during machining.
Protect:
Where the profile is being installed into a frame, machine the required groove before the frame is installed.
Use a straight edge to mark the complete kerf line.
The line must be:
Check the marked line before beginning the cut.
Measure the door-to-frame or meeting-stile gap at several points.
The standard saw-kerf arrangement is suitable where the profile can achieve the specified stop overlap without excessive compression.
Where the door-to-frame gap is less than 3mm, Norseal permits the seal to be recessed using a 5mm router cutter set to a suitable depth.
Do not establish the recess depth without first trial fitting the profile.
For the standard installation, use a power saw with a 3mm-wide blade.
Cut a groove approximately:
4mm deep
Machine the groove carefully in controlled passes where necessary.
Maintain:
Do not widen the groove unnecessarily, as the retaining section must remain securely gripped.
Where the door-to-frame gap is less than 3mm, use a 5mm-wide router cutter as permitted by the manufacturer.
Set the cutter to a suitable depth so the flexible blades project sufficiently to create the required contact.
The finished position should provide:
Test the recess depth on a suitable offcut where possible.
Remove all sawdust, chips and loose timber fibres.
Use a brush or vacuum to clear the kerf.
Check that:
Push a short section of the NOR720 into the groove before fitting the complete length.
Check that:
Alter the groove only where necessary and permitted.
Measure the first jamb, meeting stile or other required section.
Allow for the 45-degree mitred joint at the corner where applicable.
Transfer the measurement onto the NOR720 without stretching the profile.
Cut the upper end of the first jamb profile at 45 degrees.
Use a sharp cutting tool or suitable mitre guide to create a clean and accurate cut.
Do not crush, tear or permanently deform the flexible blades.
Starting at the upper end, push the retaining section firmly into the groove.
Work progressively along the length.
Check that:
Trim the lower end to the required finished position.
Repeat the measuring, mitring and kerf-fitting process on the opposite jamb.
Maintain the same profile orientation.
Check both jamb profiles for:
Measure the head section between the two jamb profiles.
Cut both ends at 45 degrees so they meet the jamb mitres closely.
Push the head profile firmly into the prepared kerf.
The three pieces should create a continuous seal around the head and jambs without open corner gaps.
Inspect both head-to-jamb corners.
The mitres should:
Re-cut inaccurate ends rather than forcing them together.
Rehang or close the door carefully.
Inspect the flexible blades against the door stop.
The NOR720 should overlap the stop by:
0.5mm to 1mm
Check the overlap along:
Correct any section with no contact or excessive compression.
Open and close the door several times.
Confirm that:
Where the NOR720 is installed at an acoustic meeting stile:
Do not alter the meeting-stile arrangement without supporting acoustic and fire-door evidence.
Where the NOR720 is used beneath a door:
This arrangement should only be used where it is permitted by the complete doorset specification.
Inspect the NOR720 regularly as part of the doorset-maintenance programme.
Check for:
Clean the seal using a soft cloth and a mild cleaning solution suitable for TPE.
Avoid:
Replace damaged sections using the same specified NOR720 profile and colour.
Correct groove dimensions, profile orientation, stop overlap and corner continuity are essential to the operation of the NOR720.
The product does not independently create an acoustically rated, smoke-control or fire-resisting doorset.
Final performance depends on:
For certified doorsets, install the NOR720 only in accordance with the applicable test evidence, assessment, certification and door-manufacturer instructions.
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