Hot tubs on decks and under gazebos

You can put a hot tub on a deck or under a gazebo, but the structure has to be designed for it: a filled tub with people in it puts far more weight on a small area than most decks are built to carry, and a roof over a tub needs headroom, airflow and a plan for rain and snow. Whoever builds it, we'll give them the tub's dimensions, full weight and service access needs before they start.

Hot tubs on decks

How much weight is that?

Here's a worked example for a mid-size tub. Water weighs about 1 kg per litre:

• 1,500 L of water (about 400 US gallons): about 1,500 kg
• The tub itself, empty (an example figure): about 350 kg
• Five adults: about 400 kg
• Total: about 2,250 kg, or roughly 4,950 lb

On a 7 by 7 ft footprint (49 sq ft) that's about 100 lb per square foot, and it sits there permanently. That's a much more concentrated load than the furniture and people most decks are designed for. A 4–5 person tub is in this range; larger tubs weigh more, smaller ones less.

How can I tell if my deck will support a hot tub?

You can't tell by looking at it. Most existing decks need added framing, beams, posts and footings under the tub area before they can carry that weight safely. Have the structure checked by an engineer or a qualified builder, and give them the tub's full weight and footprint. Ask your municipality whether the deck work needs a building permit; our permit guide covers what to check.

Building a platform for a hot tub

A deck or platform built for a tub is designed around the tub's weight from the start: footings sized for the load, beams and posts under the tub's footprint, and a surface that stays flat and level. Many people find it simpler to put the tub on a ground-level concrete pad or paver base beside the deck, with the deck built up to the rim. You get the look of a built-in tub without the deck carrying the weight.

Setting a tub into a deck

A tub sunk partly or fully into a deck looks great, but plan for service. The equipment (pumps, heater and control pack) sits behind one cabinet panel, and a technician needs to get to it. Leave that side open, or build removable deck panels or a hatch large enough to work through. Make sure the tub can be lifted out one day without tearing the deck apart, and keep the base under it drained.

Gazebos and pergolas

A roof over the tub keeps rain and leaves off, adds privacy and makes winter soaks more comfortable. Things to plan:

• Headroom and the cover lifter. Most cover lifters swing the cover up and back. Check there's room for it to open fully under the roof and beams, and enough headroom to step in and out comfortably.
• Ventilation. A warm tub under a roof gives off a lot of moisture, especially in winter. Open sides or good airflow help prevent condensation, mould and rot in the structure.
• Roof runoff. Send rainwater away from the tub and its base, not onto the cover or into the cabinet.
• Snow. The roof has to carry snow when we get it, and snow sliding off a roof shouldn't land on the tub or the steps.
• Privacy screens. Panels or lattice on one or two sides, without blocking the airflow.
• Lighting and outlets. Wiring lights, fans or outlets into a gazebo is electrical work that needs a permit, the same as the tub's own circuit. See hot tub electrical.

Ground-level patios

The simplest setup is often the best: a tub on a level concrete or paver patio, close to the house, with a short path to the back door. It's easier to deliver, easier to service and puts no load on a structure.

Hot tub deck ideas

• Steps and a handrail. Wide, non-slip steps and something to hold make getting in and out safer, especially on wet winter nights.
• Storage. A bench or cupboard nearby for chemicals, test strips, towels and the cover lifter's straps.
• Privacy. Screens, planters or a pergola on the side facing the neighbours.
• A short, dry path. The closer and better lit the path from the back door, the more you'll use the tub in January.
• Lighting. Low lighting on steps and paths, installed under a permit.
• Room around the tub. Space for the open cover and for a technician to reach the equipment side.