FAQs

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! 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.

Where door manufacturer's test evidence isn't available, the usual recommendation is to use a 15 x 4mm seal, fitted centrally at the head and both jambs of a single leaf, single acting door. (If you are in any doubt, or have a particular application you would like to discuss, please contact our Technical Services team on +852 2505 0328 for details).

If it's a fire and smoke door (which will be denoted FD30S), then do also remember that a fire seal alone will not be sufficient - you should purchase a combined smoke and fire seal, such as the Lorient DS. Don't forget to seal the threshold too - you may find our FAQ on threshold sealing helpful.

The first product we would always recommend you consider is our Batwing® seal. With proven performance for acoustic and smoke containment, a choice of sizes for different applications, and ultra-low frictional resistance for ease of door operation, it's an exceptional all-round solution. As it fixes onto the doorstop with strong self-adhesive tape, it's easy to install and you won't need to remove your door to fit it.

Alternatively, our perimeter seals, face-fixed to the door stop provide a good option, and several have been designed to accommodate uneven doors.

If you have double leaf doors, remember you will need to fit a seal at the meeting stile too.

And don't forget the threshold! - it's essential to seal it for effective smoke containment (please refer to our FAQ on threshold sealing for more information!). We have face-fixed options in both our door bottom seals and drop seals that can be installed without removing the door.

Brush seals were the first on the market (in fact, Lorient were the first to introduce them, back in 1979!), and hence they have popular appeal as the traditional smoke seal solution. Although they are still effective as smoke seals, the Building Regulations have moved on since they were introduced, most notably with the requirement for doors to provide acoustic containment, and also be easy to operate to allow access for all. With so many doors now needing to conform to these new requirements, the brush-style smoke seal is simply not up to the challenge any more. Brushes are particularly poor at providing acoustic containment, as the brush fibers allow air to pass straight through, and therefore sound too. They also provide plenty of friction, which makes doors more difficult to operate.

Fin-style seals provide a much more modern, comprehensive and indeed hygienic solution. They have better acoustic containment properties (particularly ones with dual fins) and much lower frictional resistance.

It's important though that the fin seal remains continuous around ironmongery for both acoustic and smoke containment - but this can be a challenge if the seal has centrally positioned fins. Offset fins make this much easier. This is why Lorient have introduced the Finesse™ and DS seals, with offset dual fins, for a complete acoustic, smoke, fire and low-friction solution.

The durability of some fin-style seals has been questioned in the market at times - but Lorient have extensively tested the DS, cycling it 1,000,000 times (10 times the usual industry level) on a full-size door assembly, without failure. As long as the seal is correctly installed, and the doors are suitably maintained, it will provide years of reliable service. The Finesse™ seal has been similarly tested too. It's unique in the industry, as its fins start at the base of the product and wrap around the sides of seal, both helping to hold it securely in place in the groove, and provide extra durability.

BS 9999 (an Approved Document to the Building Regulations for England & Wales) states that if a fire rated door has a gap of over 3mm at the threshold, then you do need to fit a threshold seal. It's very difficult to know before the door is installed whether the gap will be over or under 3mm, so we do always recommend fitting a threshold seal. There are other reasons for this too. It is often assumed that the threshold is a low-risk area, but extensive research has proven that this is definitely not the case - an unsealed threshold presents a major cold smoke hazard. That is why undercutting the threshold of a door leaf to provide extra ventilation is extremely risky too, both in practice and principle. Threshold sealing is also essential for acoustic containment, as an acoustic sealing system will only truly be effective if it incorporates every gap around the door, and that includes the threshold. For more information on our threshold seals, please refer to our door bottom seals or drop seals.

Over-painting of fire seals should not compromise performance in a fire situation - however, do not paint over smoke seals as this will certainly compromise smoke containment performance. If the smoke seal part of the seal has already been painted over, you will need to replace the smoke seal. Our seals are available in a range of colours, plus woodgrain and metallic finishes, so over-painting should not be necessary.

Take a look at the LAS3008 si door bottom seal, part of our Lorient Architectural Seals range.

We'd recommend you consider using a stainless steel sealing system from our range. There are perimeter and threshold sealing products included, and both the carriers and gaskets are impervious to most strong cleaning chemicals, making them ideal for hospitals. Please click to link to the following pages:

LAS4050, LAS4055, LAS4060 and LAS4065 threshold plates
LAS3050 door bottom seal
LAS8060 or LAS8070 drop seals.

Please note that while these seals will provide a comprehensive smoke sealing solution, if you have a fire rated door then an appropriate fire seal should be fitted in addition.

Many of our products have been designed with ease of access in mind, and the seals we recommend will provide exceptionally low frictional resistance to ensure the seal interferes as little as possible with the smooth operation of the doorset.

For a combined acoustic, smoke and fire sealing solution, we recommend you take a look at our Finesse™ or DS seal. Please remember that traditional brush-style fire & smoke seals provide very high levels of frictional resistance, so won't be suitable.

For acoustic and smoke containment only, either for new door assemblies or as a retrofit solution, our Batwing® seal is ideal - we've re-engineered the fins now into a unique curved design, so they provide even less resistance.

Alternatively, any of our perimeter seals mounted onto the doorstop (eg, our LAS7001 si), will provide a compression seal that will provide minimal interference.

It's vital to have a seal at the threshold for effective acoustic and smoke containment, and our drop seals (eg, our LAS8005 si) have been designed with high efficiency mechanisms, so doors can be opened with the minimum of effort.

We also offer a range of threshold ramps for situations where different floor levels need to be accommodated.

The revisions to Approved Document E to the Building Regulations for England and Wales came into effect on 1 July 2003. From that date, all planning applications requiring Building Control approval, and work carried out under Building Notice procedures, has to comply with the revised regulations.

Much of Document E relates to the acoustic performance of floors, ceilings and walls. However, for the first time, the acoustic performance of door assemblies in a number of situations is also specifically detailed.

Requirement E1 states that: “Dwelling-houses, flats and rooms for residential purposes, shall be designed and constructed in such a way that they provide reasonable resistance to sound from other parts of the same building and from adjoining buildings.”

Document E also goes on to give specific guidance about the acoustic performance of doorsets: “Ensure that any door has good perimeter sealing (including the threshold where practical), and a minimum mass per unit area of 25kg/m2 or a minimum sound reduction index of 29dB Rw (measured according to BS EN ISO 10140-1:2016 and rated according to BS EN ISO 717-1:2013). The door should also satisfy the Requirements of Building Regulation Part B – Fire safety.”

Requirement E4 covers acoustic conditions in schools, and incorporates Building Bulletin 93 as the recommended way of meeting the requirements. BB93 requires an acoustic performance for doorsets of 30dB Rw, and for music rooms, 35dB Rw.

Lorient's recommended sealing systems are specifically designed to enable these requirements to be met. It is important to remember that, while Document E says the threshold should be sealed “where practical”, extensive testing has proven that it is essential to do this in order to achieve the required level of acoustic performance.

For more information please download our Acoustic Sealing Systems for Door Assemblies brochure.

Our recommended acoustic seals will certainly help you get the best acoustic performance possible from the door assembly you have - but it's important to remember that no sealing system will improve the acoustic performance of the door leaf itself. Every door leaf will have a maximum acoustic performance, which will have been determined by testing the door construction with all the gaps around the edges filled (caulked). Many combinations of our seals have been proven to maintain a door leaf's acoustic performance to the same level as if the gaps were filled, and that's the best acoustic performance you will be able to achieve.

Some of our recommended solutions are as follows - please click on the links to product page links for more information:

For fire rated doors, our DS or Finesse™ combined acoustic, smoke and fire seals - the complete solution in one seal. Both the DS and Finesse™ have been proven to achieve an acoustic performance of 31dB Rw on a standard architectural solid door core, when tested in conjunction with a Lorient LAS8001 si drop seal.
For non-fire rated doors, we would always recommend our Batwing® acoustic and smoke seal. It has also achieved 31dB Rw on a standard architectural solid door core, when tested in conjunction with a Lorient LAS8001 si drop seal.

Do remember it is essential to fit a threshold seal to complete the system. You may find it helpful to read our FAQ on threshold sealing.

To find out more about our recommended acoustic solutions, please refer to our Acoustic Sealing Systems for Door Assemblies brochure. This also contains more information about how doors are tested, and the acoustic performance of various types of standard door construction.

We also offer a CPD seminar, entitled “Performance Door Design: The Basics of Sound Reduction”. Please visit our CPD Seminars page for more information.

This won't be a problem, provided that thick enough glass is used, with an appropriate sealing system, and the size of the aperture is limited. Conventional “Georgian Wired” glass has been tested in conjunction with our System-36/6 PLUS glazing gasket, and this provides optimum acoustic performance for most types of door construction, including FD30 and FD30S doors. This will allow for up to 0.16m2 (eg, an 800mm x 200mm or 650mm x 250mm glazing panel) to be incorporated into the door without having a significant impact on the acoustic performance. If you wish to use other glass types or larger sizes, please contact our Technical Services team.

You need to be very careful when you look at the acoustic rating of door seals. The door and the sealing system always work in combination, so the only way to really know how a seal will perform in practice is to test it on a full-size, working door assembly. Lorient always do that, and we'd suggest you ask for a copy of the full test evidence for any seal that claims to offer exceptionally high acoustic performance ratings. Do be careful if you find that any part of the door perimeter has been artificially caulked (filled) for testing purposes; or that the door assembly was smaller than it would be in reality; or that a non-standard door construction was used - any of these things may result in the seal being given an 'artificial' acoustic performance that it couldn't actually achieve in practice.

We're more than happy to provide specifiers and Lorient customers with a copy of our test evidence so you can make an informed choice!

Please contact our Testing & Technical Services team for further information on +852 2505 0328 or email sales@lorienthk.com

A threshold plate is a good idea, for several reasons:

• It will help to ensure a good seal is maintained at the threshold, by giving a firm surface for the drop seal to rest against.
• It can help to prevent weather ingress when used as part of a storm-guard system (such as our LAS3008).
• If you are sealing dissimilar surfaces (eg, carpet and vinyl), the threshold plate can cover the join to prevent both wear and tripping hazards. Our threshold ramps can also easily accommodate differences in floor heights, to make access easier for all.
• If your floor surface is particularly liable to wear and tear in places below the door (eg, a high level of traffic, or over a carpet that may become compressed over time), then a threshold plate will help to prevent these uneven areas affecting the threshold sealing.

Please refer to our threshold plates and ramps for further details.

It depends on the test evidence for the door - you will need to check this with the door manufacturer. As long as the door was fire tested with a glazing panel installed, then yes you can install a glazing panel, up to the same size (in area) that was tested, and in the same place in the door leaf.

Lorient's systems have also been tested in typical fire rated door constructions, and we hold extensive test evidence ourselves which allows for glazing panels to be fitted, up to certain sizes - please refer to our Fire Resistant Glazing Systems page and brochure (available to download from this website) for more details, or contact our Technical Services team on +852 2505 0328 if you would like to discuss your specific application.

If you are installing the doors on site, do also remember that cutting apertures for glazing (and other apertures) in a fire door on site is not permitted under the BWF-CERTIFIRE Fire Door and Doorset Scheme, even by an approved aperture cutter. This should only be done at an approved BWF glazing centre. You may also find this link to the BWF helpful, and particularly the fact card on Fire Resistant Glazing.

You will need to refer to your door manufacturer's test evidence, as this will show the maximum size of glazing panel you can fit. The sizes shown in our Fire Resistant Glazing Systems brochure relate to the sizes in Lorient's own test evidence - but if the test evidence for your door shows a smaller size, then that is the maximum size you can fit.

We do have test evidence for our fire resistant glazing systems for use in screens/partitions. The system we would recommend will depend on the type of glass you are using and the level of fire protection you need to achieve (30, 60 or 90 minutes).

Full details are available in our Fire Resistant Glazing Systems brochure, available to download here.

We'd suggest you look at our Firemaster letterplate. It has been acoustically tested in a typical FD30 door leaf, with minimal impact on the acoustic performance of the door.

It could be that you have your eye too close to the glass. The benefit of the wide angle viewer is that you can stand some way back from the glass and still see a clear image (which is much safer) - but if you stand too close the image will be fuzzy. Try standing 8-10” back from the glass.

With our LVH44 high performance intumescent fire damper, we have the production flexibility to make bespoke sizes, so please call us on +44 (0)1626 834252 to discuss exactly what you need.

For larger apertures, the LVH44 can also be installed as part of a modular system, up to a maximum size of 1200mm x 2400mm for 120 minutes fire protection in a wall application (1200mm x 600mm for floors). Please contact us if your application exceeds these sizes.

Yes, we do. Please visit our Enviromental Policy page.

Plenty!

Many of our products hold CERTIFIRE certification - an accredited independent product conformity scheme. Copies of our CERTIFIRE certificates are available to download throughout this site, against relevant products, or from our certification page.

We are also the only manufacturer of acoustic, smoke and fire seals to hold BBA certification on our mainstream range of seals. Again, our certificate is available to download from our certification page.

We extensively test our products, and hold a huge library of test evidence. Copies are freely available for customers on request. Please contact our Technical Services team on +44 (0)1626 834252 for more information.

Yes - both MSDS (material safety datasheets), and COSHH information sheets where relevant are available on request. Please contact our Technical Sevices team on +44 (0)1626 834252 for details.