We replace numerous kiln roofs each year. Our preference is to manufacture full length stainless steel panels and pack with polyisocyanurate insulation. We install these panels on the kilns, then cover with an aluminum standing seam roof. One key is adding slope to keep water and condensation from puddling on top and inside the panels. The picture is a complete rebuild of masonry kilns, including new structure and complete roof system. Also, when the option is available, we prefer to install vents in the front and rear walls.
Again, stainless steel inside panel packed with insulation, covered with aluminum standing seam roof. New heavy gauge aluminum roof vents shown in this photo.