Abstract: A protective cap for covering a top of a wall. The cap is constructed in the form of an elongate channel having an upper plate and opposing sidewalls. Each sidewall tapers inwardly to an innermost side edge, then slants outwardly from that edge. The sidewalls are preferably flexible and resilient with sufficient elastic memory to function cooperatively as a gripper. The cap is placed onto the top of an outdoor wall, with the upper plate of the cap disposed along the top and the sidewalls extending downwardly along opposing sides of the outdoor wall. The cap is constructed such that the outdoor wall is wider than the distance between the innermost side edges when the sidewalls of the cap reside in a natural, unbiased position.