Structural Damage:In case you notice sagging trusses or rafters, it implies serious structural damage which needs immediate professional attention. Persistent Mold Issues:If mold issues persist despite regular cleaning efforts, hire professionals as constant moisture exposure suggests ongoing leakage problems...
You should have the roof deck, roof frame and trusses inspected before installing metal over-top. Make sure the roof frame will be able to support the added weight. I know metal is light, bus asbestos, plus the layers of liquid roof do add up to quite a lot of weight. Good Luck and...
Warped, Curved, or Arched: Look along the flat length of the lumber. If the lumber bends slightly to the left or right it will form an arch or a dip horizontally. It is still useable for joists or the trusses/rafters, not great as a stud. Ensure they are laid arch up; the weight ...