Bi-fold door lintel

Got a question on lintels? Follow this advice

Marketing ALL, Concrete Lintels, Specification, Steel Lintels 28 Comments

We get asked all sorts of questions about our lintels, often about what lintels are used in certain circumstances and what loads our lintels can take and how we calculate the loads of the lintels. A lot of the time we can answer your questions but we also need further information to help as well.

Here are four basic questions or areas where we receive a lot of queries, and some advice as to how to get a quicker and more accurate response.

What lintel do I need for Bi-fold doors?

Bi-fold door lintel selection

Bi-fold doors can cause a headache with lintel selection, as the standard allowed deflection can mean the door won’t operate correctly.

If you’re not sure what bi-fold doors are they are two or three or often more doors or window panes that span to the floor and are often used to exit into a patio or garden area. The bi-fold element means they concertina up so you can have a wide opening out to the back that really opens up your house. Because of the wide span, this often causes issues for homeowners and builders when it comes to appropriate lintels to install above the bi-fold door.

The British standards for lintels allow for a small percentage of deflection, meaning that the lintel can bend ever-so-slightly. Over a standard window or door, this deflection has no impact on the usage and is not even visible.

Bi-fold doors are a different story. Because of how a bi-fold door opens and shuts, even the slightest deflection in the lintel above can render the door unusable, because it simply won’t slide open or shut. To this end, we recommend a heavy-duty or even a rolled steel lintel above a bi-fold door to ensure that there is absolutely no deflection. This often depends on the span of the opening and the load, so we would need further details on a project-by-project basis.

Can I have a price for X?

Lintel selection

Selecting and specifying the correct lintel depends upon a number of factors. We can provide assistance if you can advise of the details below.

Yes, is the short answer. We are always happy to provide a quote however it is worth bearing in mind that because we put a lot of business through builders merchants, as an installer of our lintels you will invariably get a better price from one of our merchants or distributors. If you want to find out where your nearest stockist is, just speak to the sales team on 01455 272457.

The opening is X, the brickwork is Y; what lintel do I need?

These are certainly two key factors that we need to know in order to advise on the type of lintel, but we often need to know more – see below for more on what we require. You can also have a look at our lintel selection guide for builders, and our lintel selection step-by-step guides.

What lintel do I need above my kitchen?

This is similar to the above – there are certain criteria we need to know before we can even advise on a suitable lintel.

Please take note
It is also worth pointing out that whilst we can advise the type of lintel based on the information you provide, we are not building regulations, or building control and are not responsible for the structural integrity of the building you are working on.

What information do we need to know?

In order to advise on lintel selection and usage there are basic bits of information that we would need in order to provide a suitable answer:

  • The size of the opening
  • The wall construction
  • The height and type of masonry above the opening
  • If there is 600mm of masonry either side of the opening
  • If there are any floor joists bearing onto the lintel and the span of the joists
  • If there are any roof trusses bearing onto the lintel and the span of the trusses

This information along with site drawings will help significantly.

Hopefully, this goes some way to help you understand what we need in order to provide a sufficient answer. If you still have questions or are unsure of what we have advised, then please contact our technical team, or seek the advice of a structural engineer or equally qualified professional. Alternatively, you can visit our FAQ (Frequently Asked Questions) page for more information. We also have two separate articles on frequently asked questions:

Frequently asked questions part one

Frequently asked questions part two

Comments 28

  1. I have a window opening to construct into a stone wall.
    The window span is 1m, the wall above the lintel is .8m, the wall thickness is .6m and there is a wall plate and roof truss.
    I will need a fair face lintel for the front and standard lintels to make up the remainder of the wall thickness.
    When calculating the size of lintels required do I calculate the whole area above the lintel or the width of the lintels being used.
    Hope this makes sense.
    Thank you

  2. Could you recommend/ quote for a closed eaves lintel. The span will be 3m, brick to brick and supporting a traditional roof.


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    2. I have an opening of 4.8m above Bi-folding doors. The loading on it from flat roof is ( 3.25 KN/m). What type of catnip lintel do you recommend?

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        Thanks for the message.
        We wouldn’t recommend a catnic lintel, we would recommend one of our own. The technical team will be in touch.

  3. Hi, I have an opening of 3100mm with 600mm brickwork either side. I am hoping to have 3 courses of bricks above the lintel and the wall will be a 90mm cavity with 100mm blocks on the inside wall with wall plate above.
    A pitched, tiled roof with a 17.5 deg pitch and sandroft Calderdale roof tiles covering an area of 22 sq metres. What lintel would you recommend ?

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  4. Hi,
    I am enlarging a lounge window in my traditional 1950s house to then install bifold doors, so I am concerned to get the right lintel with <1mm nominal live load deflection as required by the door manufacturer. Please could you advise?
    1. The opening will be 2500mm wide in a brick / cavity / brick wall 280mm overall width.
    2. Above the opening is 3000mm height cavity brickwork of the first floor, penetrated by one bedroom window 1000 x 1200mm centrally located above the lounge opening below.
    3. There will be minimum 600mm masonry nib each side of the opening.
    4. The timber first floor will be supported on the lintel and the floor span is 3300mm.
    5. The roof of the house above is traditional pitched and hipped cut timber frame with double lap rosemary type plain clay roof tiles. The roof load bears onto the inner leaf of the cavity wall.

    I have some pdf drawings of the house if this assists.

    It would be great if you could help.
    Many thanks,

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      1. Hi Andy,

        Many thanks to you and to Simon for all your help. I will be arranging to have the Stressline lintel installed that Simon established as appropriate.

        Best regards,

  5. I am building a summerhouse in my garden. I want bi-fold doors but wasn’t sure if I need a steel lintel ? It’s all wood and stud work throughout. The door opening is approx.2.7m long. The height (not built yet) but about 2m. Ive seen some bi-fold doors that are these dimensions, they are 3 panels. Can I get away with a strong re-inforced wooden header to fit frame into, or do I need a steel plate or lintel?

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  6. Hi I’m looking at having some bifold doors fitted where my dining room window is, I’ve paid for a structural engineer to calculate, his information is pretty sketchy them beam needed is 178×102 ub +10 mm bottom plate if needed the beam would need to be 2.7m, I’m not sure where the plate would need to be welded or if there’s an alternative lintel that could be used?
    I’ve got a spare beam of 152×152 could this be used?
    It’s a double skinned wall with hardly any cavity.
    I hope this makes sense.

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    2. Hi, I need advice on which of your lintols I need, I’m fitting bifold doors to a single storey extension, spec as follows,
      3740 clear opening
      Internal skin thermalite 100mm block
      External skin 100mm concrete block
      50mm cavity
      1200mm of block work above the opening forming a parapet wall to a balcony
      Balcony does not load bear over the opening
      Blockwork either side of opening for at least 600mm
      Your help in selecting the appropriate lintol would be appreciated

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  7. Hi I’m installing bifold doors in a single storey extension, so only joists and flat roof to be held up. Width of doors will be 4m x 2.1m any suggestions for type of lintel required..

    Many thanks,


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  8. Hi I’m having bi-fold doors 3.6m wide fitted at the back of my house this will not be holding much up theres going to be a glass roof sloping and 1.2m in length from the house would this need a lintel?

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  9. Hello,

    I have an single storey extension with a tiled leantoo roof.
    The bifold opening size is around 4500mm
    I am going to need a goal post because no place to sit a steel beam.
    Could you advise.

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  10. Hi, I’m looking at purchasing a house with a side conservatory with double upvc doors from the kitchen. There are some cracks on the wall above the doors on the conservatory side of the wall. The previous home buyers report didn’t mention any problems. I am wondering if this could be a lintal problem or would this be repointing as the cracks aren’t showing on the other side of the wall. Any ideas at all?

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  11. Hi. I have a 3m opening for a window. No floor above the opening, just a large tiled roof. What lintle do you recommend?

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