Air Holes and Drain Holes in a Fire Pit

Drain Holes Keep Rain Out of the Fire

An open fire pit is a bowl, and in a summer storm it fills. A gas fire pit maker's troubleshooting section lists water in the fire pit as a common complaint and gives three causes: dust from the media blocking the weep holes in the burner pan, an enclosure without drainage, and no cover. Its fix is to remove the media, unplug the weep holes and make sure the enclosure drains.

Clay is the extreme case. A chiminea supplier notes that clay chimineas have no drainage holes and become waterlogged when left in the rain, and warns never to use one until it is completely dry. Steel bowls without a drain simply hold water against the metal until it rusts through.

Wet ash is part of the same problem. Rain on a bowl full of old ash makes a heavy paste that holds water against the bottom and clogs whatever drain hole there is, which is one more reason to empty cold ash every few fires.

Gas Fire Pit Enclosures Need Vents on Two Sides

A gas burner set into a block or stone surround needs air moving through the box under it. The Firegear manual calls for a minimum of 18 square inches of cross ventilation on each side, to keep the inside of the enclosure dry, and shows vents placed on opposite walls so air can flow across.

The same manual warns against setting the fire pit directly on grass, dirt or rocks, because that can block the ventilation, and repeats that drainage has to be built into the enclosure. A surround with no vents and no drain traps moisture around the gas valve and the fittings.

Air Holes for a Wood Fire

Wood burns with air reaching it from above and around, while charcoal needs air from underneath, a chiminea supplier explains. A wood pit with a raised grate and a clean floor gets enough air to burn hot; a pit choked with old ash does not.

Smokeless fire pits use holes on purpose. One maker describes a double wall: air enters low, heats as it rises between the walls, and leaves through a ring of holes near the rim, where it mixes with the smoke and burns it a second time. The same maker notes that ash building up in the bottom blocks that airflow and makes the fire smokier.

Holes and Gaps in a Block Fire Pit

A ring of wall block set on soil drains through the ground. Belgard suggests cutting out the pavers and setting the pit on the same base, which it says keeps ash from washing out and the pavers from settling. A block pit built on a solid slab needs a planned way for water to leave, either weep gaps at the base of the wall or a drain through the slab.

Outdoor fireplaces face the same problem higher up. One outdoor fireplace maker recommends a drainage pan with tubes or weep holes wherever water can collect under the unit, sloped 1/8 to 1/4 inch per foot toward the drain.

Keeping the Holes Open

Holes only work while they are clear.

• Empty cold ash from wood pits every few fires so the floor and any drain stay open.
• Keep gas media dust-free and loosely placed so the pan's weep holes drain.
• Leave the enclosure vents unblocked by planters, cushions or stored firewood.
• Cover the pit between uses, and take a combustible cover off before lighting.
• After heavy rain, let a gas pit dry out before use, as its maker advises.

When a Gas Pit Keeps Flooding

If water still pools in the burner pan after the weep holes are clear, the enclosure itself is the problem, and that is our gas fire pit repair work: vents, drainage and the burner pan. For a new built-in pit, the vents and drain are planned before the first block is set.

An experienced technician from our local, family-owned company does the free inspection and writes the estimate. Proudly American and practical, a Proudly American crew would rather drill a drain in the right place than replace a valve that sat in water.