Hi all , I have been asked to make a frame for an opening that is 52" x 30" . This is voluntary work and I don't have a workshop with machinery . The more basic the better as I'm learning. It's at the top of an outside staircase & is part of shelter that stops rain blowing in through the door to the main building. I would attach a picture but I've struggled to do this in the past. My questions are , what size timber should I use , as in thickness/ width & could it be glued / screwed , as I don't know if I'm capable of mortise & tenon . Thanks Tony