Gas or wood: choosing the fuel for a new fireplace

The short version

Neither fuel is the right answer for every house. The better choice depends on how often you expect to light the fireplace, how much handling you want to do, and what the house can accommodate for venting. The two compare like this on the points that settle the choice.

• Lighting: gas starts at a switch, remote or knob; wood is built, lit and tended.
• Shutting down: gas goes off at the switch; a wood fire burns down and its ashes stay hot for days.
• Venting: direct-vent gas units can leave through a side wall; wood needs a chimney that climbs out through the roof.
• Fuel: gas comes through a line or from a propane tank; wood has to be bought or cut, dried and stored.
• Upkeep: both call for a yearly check; wood adds sweeping as deposits build up and ash removal after fires.
• Experience: wood gives the crackle, the smell and a fire you can tend; gas gives a steady flame you control.

Living with each one

Gas is built for convenience. Depending on the model, it lights from a wall switch, a remote or a thermostat, and it goes out the moment you turn it off. There is nothing to carry in and nothing to clean out between uses. The flame looks the same every time, which some people love and others find less alive than a wood fire.

A wood fireplace asks more of you and gives something different back. You build the fire, open the damper, keep the screen closed, add wood and let it burn down before bed. Ashes have to cool before they come out, and they go into a metal container with a lid, kept away from anything that burns. Some owners enjoy that routine; some tire of it. If you expect to light the fireplace on a whim for an hour after work, gas fits that pattern better.

Heat in the room

Gas fireplaces come in two listings, and the difference matters if heat is part of the goal. A vented gas fireplace heater is listed to ANSI Z21.88 and is designed and rated as a room heater. A vented decorative gas fireplace is listed to ANSI Z21.50, and its job is the appearance of the flame. A direct-vent unit of either kind is sealed from the room and takes its combustion air from outside.

An open wood fire warms the people in front of it, but it also draws room air up the chimney to keep burning. In an air-conditioned or heated house, that air has to be replaced from outside, and R1006 of the Florida Building Code, Residential, therefore requires an outside air supply for a fireplace unless the room's pressure is held neutral or positive by mechanical ventilation. If you want real heat from wood, a wood-burning insert with a door does that job better than an open firebox.

What each one asks of the house

Wood needs a chimney through the roof, and its height is set by rule. For masonry, R1003.9 wants the top at least 3 feet above the roof where the chimney exits, and it must top anything on the house within 10 feet by at least 2 feet. A factory-built wood unit comes as a system with its chimney, tested together under UL 127, and follows the height and clearances in its listing. Either way it needs a noncombustible hearth extension ahead of the opening, and a masonry fireplace needs a concrete footing under it.

Location is where gas is more flexible. A direct-vent unit can leave through a side wall, provided the termination keeps the distances its manual lists from windows, doors, soffits and walkways. A B-vent unit needs a vertical vent through the roof. Gas units also need a gas line to their shutoff valve, run by a gas contractor or the propane supplier, and some need an outlet for a blower or electronic ignition, added by an electrician. Both kinds are permitted work.

Upkeep over the years

Under NFPA 211, the chimney or vent gets an inspection once a year, whatever the fuel. A wood fireplace adds sweeping whenever the inspection finds deposits building in the flue, plus the ongoing wear of a firebox that sees real flame: mortar joints that open, firebrick that cracks, a damper that rusts.

For gas, the manuals put a yearly check of the burner system and venting in a technician's hands, and ask for the burner and control compartment to be kept clean. The parts that wear are different: pilot sensors, igniters, batteries in receivers, the glass gasket and the blower. Neither fuel is maintenance-free. The difference is in who does what: wood puts more of the routine work in your hands, gas puts more of it in a yearly service visit.

Fuel on hand

Wood has to be dry to burn cleanly. EPA's Burn Wise program advises burning only dry, split, well-seasoned wood and storing it outdoors, stacked on a rack clear of the ground and covered on top only. Wet or green wood makes more smoke and leaves more deposits in the chimney.

Gas needs a supply. Natural gas comes through the utility's line. Propane comes from a tank outside the house, and the fireplace manuals require propane tanks to stay outdoors. If your house has neither, a propane tank or a wood fireplace are the two ways to get a live flame, and an electric unit is the way to get the look without either. Our guide on electric vs gas fireplace covers that comparison.

Safety differences

Both fuels are safe when installed to the listing or the code and kept up, but the risks differ. Wood brings sparks, so the screen stays closed; hot ashes, which need a metal container outside; and chimney fires if deposits are allowed to build. Gas brings the possibility of a leak, so everyone in the house should know that a gas smell means getting out, then calling the utility or 911 from outside. Glass-fronted gas units built to the 2015 revisions of their standards come with a barrier screen because the glass gets hot enough to burn.

Both produce carbon monoxide when they burn, and both depend on a working vent or chimney to carry it outside. A carbon monoxide alarm near the bedrooms is sensible with either one.

What moves the cost of each

Without quoting figures, the cost of either project is driven by the route more than by the unit. For wood, a masonry fireplace is the largest job, because of the footing, the masonry and the time involved. A factory-built wood fireplace costs less to build but still needs a full chimney through the ceiling, attic and roof. For gas, a direct-vent unit on an outside wall with a short vent run is the simplest installation, and the job grows with vent length, a roof exit, the length of the gas line and any electrical work.

Running costs follow your habits: the price of wood or gas where you live and how often you light the fireplace. Upkeep costs follow the yearly inspection or service, and whatever repairs it finds. An existing wood fireplace can also be converted to gas later with a log set or an insert, which is a different project from building new.

Choosing for your household

Picking a gas or wood fireplace is about use. If the fireplace will be lit on short notice, used by several people in the house, or placed in a room with no path to the roof, gas is the practical fit. If the point is the fire itself, the sound and smell and the ritual of building it, and the house has a route for a chimney, wood delivers something gas does not. Either way, the first step is the same: a visit to see where the fireplace would go and how it would vent. That visit is the start of any fireplace installation, and the written estimate that follows lays out what each option involves.