Do bifold doors need a lintel?
Yes. A wide bifold opening needs a structural lintel rated for the load above it, and top-hung systems need the opening strengthened. Choose the lintel by span and by what sits above the opening, such as floors, a flat roof or heavy brickwork.
How do you choose the right lintel?
Lintels are grouped by load. Standard or medium duty is for wall load only. Heavy duty is for a floor or flat roof above. Extra heavy duty is for heavy masonry or multi-storey loads.
What about bearing and propping?
Allow at least 150 mm bearing on solid masonry each side, so a 2,400 mm opening needs a lintel of at least 2,700 mm. Prop the wall above the full span before removing masonry.
When do Building Regulations apply?
Enlarging an existing opening needs Building Regulations approval. Part L also affects lintel choice, because standard steel lintels create a cold bridge, and thermally broken lintels are available. MLI Building Products can supply aluminium bifolds. Ask a structural engineer or building control about the lintel.
Need a trade price? Call the trade counter on 01903 262 636 or visit us at Unit 1, Friar Walk, Worthing. We offer free delivery within 30 miles.
← Back to Supply Only Aluminium Windows and Bifold Doors FAQs | See our supply only aluminium
