Washington Minimum Header Structural Requirements for Manufactured Home Alterations are a set of guidelines established by the Washington State Department of Labor and Industries. This set of requirements is designed to ensure the safety and structural integrity of manufactured homes undergoing alterations. There are two main types of Washington Minimum Header Structural Requirements for Manufactured Home Alterations: those for alterations to single-wide homes and those for alterations to double-wide homes. For single-wide homes, the minimum header size is 2×4 inches with a minimum bearing width of 2 inches. For double-wide homes, the minimum header size is 2×6 inches with a minimum bearing width of 3 inches. Additionally, the header must be secured to the wall with at least two nails per joist and the header must be supported by a minimum of two studs. All headers must be adequately braced and anchored to the supporting wall structure. Lastly, Washington State also requires all headers to be covered with a minimum of 1/2 inch of drywall or equivalent material. This is to ensure that the header is protected from weather and other environmental elements.