We have a fourty foot by twenty foot bifold door on our shop and love it can drive the combines in no wiggling or swearing and the shop has a 20 foot celling . I went to siast in Saskatoon in the AG mechanics course and they had the doors with the post in the centre which gave them fourty feet just seemed.like a.pain in.the ass. With our big door we just don't open it unless we need to in winter
How do you find it is for sealing up? I think it could be sealed up well except the hinge area might be a bit tricky. Then again I guess it is really no different than an overhead and at least there is only one joint to worry about. I really like the concept of the HP doors but because of the way they move, I don't know if they can be sealed up along the sides as well.