For a dramatic wide-span opening, Altherm bi-folds are hard to beat. They can be built in a range of configurations - all capable of stacking to one end of the frame.
The innovative lay-back bi-fold allows clear decks, with panels folding flat against walls. This option is available in 2-panel and 2+2 configurations. Our unique, bottom-rolling bi-folds ensure the weight is carried on the sill where it has maximum support, which makes the moving panels glide easily.