I am building my sukkah as we speak, can I use duct tape to reinforce it?

Shalom, Thank you for your question. To use duct tape on the Succah depends on where you want to use it. To use tape on all parts of the Succah (including the beams that will support the sach [the natural roofing]) is perfectly fine. However, to use tape to hold down, or hold in place, the sach itself could be a problem. If the sach is heavy enough that it would remain in place under normal wind conditions in your location, then using tape (and other forms of tying it down) are allowed – as this is only being done to add support for abnormal wind conditions. However, if the sach is light, and you fear it may blow away, or fall off, even in normal conditions, then there is a question as to whether it may be tied down with materials that are not in themselves permitted for the sach roofing (such as duct tape, zip-ties, metal wiring, or plastic sting). In order to avoid any question, one should try to avoid using such tape (or other materials, unless they are themselves permitted and still in their natural form – such as vines, or hemp). If though they were used though, then the halacha certainly permits such a succah. Let me add that there are opinions that allow using such ties without any question – and in my mind it is clear that it is preferable to rely on them rather than have your Succah blow away and miss out on the mitzvah entirely. Blessings.