Planning an outdoor kitchen

Layout comes first

The layout decides everything downstream: where the gas comes up, where the outlets go, and how the pad drains. A working kitchen has a grill with at least 24 inches of counter on one side and 12 on the other, a landing spot near the door to the house, and enough clearance behind the cook that people can walk past. Bar seating goes on the side away from the grill.

Grills need clearance from combustibles. Most built-in grill manufacturers specify 24 inches or more from wood, vinyl siding, and a pergola post, and a longer distance from anything overhead. That rules out backing the grill against a house wall with vinyl siding or tucking it under a low cedar beam.

Decide early what the kitchen will include: grill only, grill and side burner, or grill, fridge, sink, and storage. The utilities and the island size follow from that list, and adding a fridge after the island is built means cutting into finished stone.

Gas and electric runs

Natural gas is run from the house meter in a buried line, sized for the total load of the grill and any burners. Propane comes from a tank and is regulated at the island. Either way there is a shutoff valve at the island, a sediment trap before the appliance, and a flexible connector rated for outdoor use. Gas work is done by a licensed plumber, and most towns inspect it.

Electric goes in a buried conduit, usually PVC at 18 inches of cover, on a dedicated circuit from the panel, installed by a licensed electrician. Every receptacle in the island is GFCI protected with a weather-resistant cover rated for use while a cord is plugged in. A fridge, an ice maker, lighting, and a rotisserie motor each need a receptacle, and it is cheaper to put in one extra than to add one later.

Both runs go in before the patio base, or through a sleeve set in the base if the patio comes first. A sleeve is a length of 2 or 3 inch PVC laid under the paver base from the house side to the island location. It costs almost nothing during construction and avoids lifting the patio later.

Counters and appliances that survive winter

The counter takes the most abuse. Granite is the standard choice: it handles freeze and thaw, heat from the grill, and UV without fading. Sealed concrete counters work if the mix and the sealer are made for exterior use, and they should be sealed every year or two. Engineered quartz is not rated for outdoor use by most manufacturers, since the resin fades and can craze in sun.

The island itself is usually concrete block or a steel stud frame with cement board, faced with a stone or brick veneer rated for freeze-thaw. Wood-framed islands rot. Stucco over the frame is another option, but it hairline cracks in this climate and needs patching.

Appliances should be 304 stainless steel at minimum. Near a saltwater pool, 316 stainless holds up better against chloride corrosion. Doors, drawers, and the grill hood should have covers for winter, and a fridge that is not rated for outdoor use will fail in its first winter.

Drainage under the pad

An outdoor kitchen is heavy. A 10 foot island with a stone veneer and a granite top can weigh over 3,000 pounds, and it cannot sit on a patio base built for foot traffic. The island gets its own footing, either a poured concrete pad on compacted stone or footings below the frost line at 36 to 42 inches, depending on the town and the size of the structure.

Water has to get away from the base. The patio around the island is pitched away from it and away from the house, and if there is a sink, the drain runs to a dry well or to a sewer connection where the town allows it. A sink drain that dumps under the patio will undermine the base.

The drainage and excavation page covers what goes under any structure on the property. Kitchens added to an existing patio need the base checked first, since a kitchen adds real weight to a patio that was not built for it.

Roof or pergola, and ventilation

A pergola gives shade and a place to mount lights and a fan. A solid roof or pavilion keeps rain off but changes the rules for the grill. Any roof over a grill needs a vent hood rated for outdoor use, sized for the grill's output, and ducted out through the roof. Without one, grease and heat collect in the structure.

Pergola and pavilion posts go on footings below frost, with a post base that keeps the wood or aluminum off the concrete. Cedar, fiberglass, and aluminum are the usual materials. Cedar needs finishing every few years, fiberglass and aluminum do not.

Ventilation inside the island is a separate item. Propane is heavier than air and pools at the bottom of a closed island if a fitting leaks. Islands with a propane tank or any gas connection inside need vent openings near the bottom and top of the enclosure, and most grill manufacturers require them in their installation instructions.

Sequencing with the patio

The right order is: excavation and rough grade, drainage and utility trenches, footings for the island and any structure, patio base, island frame, then patio pavers, then veneer, counters, and appliances, then lighting and the pergola. Doing the island before the pavers means the pavers are cut to the island instead of the island sitting on top of a finished patio.

When a kitchen is going on an existing patio, some of the field is lifted to run the sleeve, set the footing, and reset the pavers around it. Lifting and resetting is normal work and it is the reason pavers are the preferred surface under a kitchen, since a poured slab would have to be cut.

Most kitchens are two to four weeks on site once materials arrive, and granite is templated after the island is built, so the top arrives a week or two after the frame. The outdoor kitchens and living spaces page describes what one crew handles under a single scope.

Questions