How to Make Foundation Vents Out of Stone

Chose a stone that will fit snugly in the space you plan to put the finished vent in your foundation. Place it on a surface safe for stone cutting.

Fit a diamond blade into your saw. Make sure the blade is small enough to cut within the edges of the stone block. For example, If your block is 1 foot by 6 inches by 6 inches, the blade should be no more than 4 inches in diameter, so it will cut within the edges of the sides of the block.

Put on your safety glasses, mask and gloves to protect yourself from bits of stone and dust.

Hollow out the stone block so that you are left with an empty rectangle shape. If your block is 1 foot by 6 inches by 6 inches, begin by cutting around the entire perimeter of a 1 foot by 6 inch side, staying about 1 inch in from the outside edge. Cut through the 6 inch depth of the block to make an 1 inch wide, 1 foot by 6 inch frame with a 6 inch depth. Lay the block on one of the hollow sides.

Cut the screen so it is an inch longer in both height and width than the hollowed out space in the stone block. Cut out a 1/2 inch square at each corner. Lay the screen to cover the hollow space on the upward facing side of the block.

Bend the edges of the screen upward (1/2-inch from the edges, at the corners of the squares) with the pliers so that the screen can slide into the hollow space with the bent sides running parallel with the inside of the stone block. Push the screen down through the block so that it reaches the opening at the other side.

Apply the epoxy adhesive over the parts of the screen the rest against the stone block interior, working some in between the screen and the stone, and allow it to dry completely. The screen should now be affixed to the interior of the stone block, facing out at one of the hollow sides, completing your stone foundation vent.