Bifold doors make an excellent addition to the home. Consisting of several glazed panels that fold and stack on top of one another as the doors are opened, they flood the home with natural light whilst creating a chic transition between the inside and out. For anyone who is interested in a set, you may have wondered ‘what lintel do bifold doors need?’. So as bi-folding door experts, we thought we would answer this question and more.
What is a lintel?
The lintel is the horizontal beam that runs above the opening for a window or door. Their purpose is to provide essential structural support. To comply with British Standards for construction, it is possible for lintels on windows and doors to bend slightly without affecting how they are operated, or for the bend to even be visible. However, this is not the case for the bifold doors…
Lintels for bifold doors
Because bifold doors open in a concertina style, where their individual door panels fold and stack on top of one another, even the smallest bend in the lintel can stop them from sliding open or shut. Therefore, it is recommended that a heavy-duty or rolled steel lintel is used for bifold doors because this will ensure there are no bends present.
However, the best lintel option is also affected by various other factors, such as:
- Size of the opening
- Weight of the doors
- The type and height of masonry above the opening
- If 600mm of masonry is present on either side of the opening
- If any floor joists or roof trusses are bearing onto the lintel and the span of any joists or trusses
Another important consideration is whether they are top or bottom running. For example, Accoya timber bifold doors are top running and aluminum bifold doors are bottom running. However, we take care to ensure the lintel is absolutely fit for purpose.
Do I need a structural engineer for bifold doors?
If a new opening is being created for bifold doors, our structural engineer will be given the task of calculating and producing drawings to ensure adequate structural support. However, on most occasions, an engineer will assess the suitability of the existing lintel, which is normally sufficient.
Reddish Joinery works closely with our structural engineer, who will assess your property and choose the correct lintel.
What size lintel do I require?
To determine your required lintel size, measure the width of the opening where your bifold doors will be fitted and then add a minimum of 150mm to each end. So, for bifold doors that are 2100mm wide, you will need to add 300mm (150mm x 2) to this, giving you a total of 2400mm.
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