Composite structural board and wall systems containing same

A composite structural board comprising:

• a) a structural board;
• and
• b) a water-resistant barrier sheet having a basis weight 100 g/m2 or less, a hydrostatic head of 55 cm or greater, a Gurley Hill porosity of 250 seconds or greater, and a moisture vapor transmission rate, of at least 130 g/m2/24 hrs, the water-resistant barrier sheet having an inner face and an outer face;
• and
• wherein a face of the structural board is discontinuously attached to the inner face of the water-resistant barrier sheet by a permanent adhesive and a non-permanent adhesive, wherein the board has a section using the non-permanent adhesive between the structural board and the water-resistant barrier sheet that can be peeled apart from the board for nailing or taping and then re-applied, the water-resistant barrier sheet fully covering the face of the structural board;
• wherein the composite structural board has
• i) attached areas between the face of the structural board and the inner face of the water-resistant barrier sheet, and
• ii) unattached areas between the face of the structural board and the inner face of the water-resistant barrier sheet;
• the unattached areas between the face of the structural board and the inner face of the water-resistant barrier sheet defining paths by which a liquid can move between the face of the structural board and the inner face of the water-resistant barrier sheet.