How are the treads constructed?
Our basic tread is an open steel sub-frame with screw holes to mount a wood tread. Formed diamond plate treads are available on special order. Smooth sheet metal treads are available on special order but are not a practical choice. We feel they have no advantage over the open frame since they also need to be decked with wood for most interior uses, such as carpeting. Natural woods are more attractive on an open frame stair. Your building codes may require a partial riser for residences. A partial wood riser with a maximum 4″ air space is commonly used.