Manufacturers of excellent quality roof lanterns and aluminium bi-folding doors
Threshold is the name given for the bottom of the door (the part you step over).
The drawing you can see is the most popular way that it is done for a bi-folding door that opens outwards into the garden, there are many other ways it can be done using different methods and profiles depending on your requirement.
We advise that you always ask when ordering.
Between the two black lines measures 75mm (total theshold height).
When a bi-folding door is installed it sits on the outside course of brickwork if that brickwork is 75mm lower than fully finished floor level, you will not step over any threshold.
Fully finished floor level meaning tops of carpet, tiles, laminate or any other flooring type used.
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