Small Diy Outdoor Fireplace . Make sure that each new block is level with the previous one. Next, build up the sides of the fireplace by stacking one block at a time. Pima II DIY Outdoor Fireplace Construction Plan Diy outdoor from www.pinterest.com Make sure you have information of underground cables and sewers, if any. Ensure that the pond has stone or concrete lining, not pvc, epdm (a synthetic rubber), or other flammable pond liners. In terms of color, the fireplace’s dark metal frame perfectly complements the white framing of the windows and doors on its left and right.