This kind of steel roofing takes advantage of flat panels with vertical ribs on each end. The panels are fixed together and to the roofs under the vertical ribs. Housing guidelines: You might require to decide on roofing that fulfills the necessities of the housing Affiliation or metropolis ordin

Any triangle or quadrilateral (even non-convex) can be employed as a prototile to kind a monohedral tessellation, generally in more than one way. Copies of an arbitrary quadrilateral can form a tessellation with translational symmetry and 2-fold rotational symmetry with centres in the midpoints of a