Abstract: A deck gutter is illustrated for mounting beneath the surface decking of a wooden deck between adjacent wooden joists. The deck gutter includes "J" shaped hangers that are mounted along an incline with respect to facing adjacent joist surfaces. A uniform cross-section gutter panel 56 is mounted between the hangers for receiving rain water through the cracks or spacing between adjacent decking boards for conveying the water away from and protecting the space below the deck surface. The gutter panel 56 has a central portion 58 with side wall portions 60, 62 extending upward to flanges. Each of the side wall portions has a "Z" shaped expansion band for accommodating during spacing between the joists and any bowing that may occur along the length of the joists.