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How to Determine if a Deck Can Support a Hot Tub?

how to determine if a deck can support a hot tub
Written by Kai Michel
Last Update: August 10, 2023

In general, most decks are already strong enough to put up with a hot tub of any kind on their backs since they are made to handle at least 100 lbs of load per square foot.

You may consider adding some extra support down below the deck in case yours is designed to hold less than 70-80 lbs of weight capacity per foot.

Sort out the load-bearing capacity first if you are planning to build a brand-new deck. Many issues will arise along the way as you get going, such as the type of the soil, the size of the footing, the overhang rules, the spacing of the joists, and more.

How to Determine if a Deck Can Support a Hot Tub?

Consider the full weight

If you’re preparing for a hot tub placement on your deck, think about the poundage of a completely occupied tub with all the water and people with their stuff inside and around it.

The load-bearing capacity of a deck is influenced by multiple items from the timber to the construction model to the support posts and the beams.

Consult a professional

Even though it is totally possible to place a hot tub on a standard wooden deck, you can choose to upgrade a few parts to make the deck more resilient.

Your wooden deck will probably backload a hot tub with no additional support if it is slightly lower to the ground; less than 2 feet high.

Consult your engineer friend or a construction expert before you put the tub down onto an old deck or when you build a new one.

How Much Does a Hot Tub Weigh?

Hot Tub Weigh Chart

Average weight

A smaller unit for 2-3 people weighs about 500 lbs when empty and nearly 3,000 lbs with full water and a couple of hundred more with people.

A six-seat unit roughly weighs around 1,000 lbs empty and 6,000 lbs full.

Types of Hot Tubs for Decks

From a diverse range of materials and features, we picked out some of the most advanced and common hot tubs that would best sit on your deck.

We’re only using the term “hot tub” as a standard for all types and features.

1. Portable

Portable hot tubs are featured as individual units and can be easily relocated. In reality, they’re not as portable as they sound because of their weight and size.

Their title got validated since you receive all the obligatory equipment needed to operate your tub solitarily contained with them. You can get one of these portable luxuries for $300 to $1,000 if they interest you.

2. Inflatable

Inflatable hot tubs are actually portable with the weight of 60 to 100 lbs deflated. They’re usually made of plied vinyl or PVC and are extremely well-made tubes.

You may not get necessary equipment such as a pump or a filtration scheme but they often bring proprietary pumps with them.

These tubs weigh far less than other models and you might find them useful if you are concerned and doubtful about your existing deck.

A medium 4-seated unit will weigh approximately 2,500 lbs at full capacity and cost $300 to $1,000. It’ll take your deck to hold about 75 lbs at a max.

3. Acrylic

They are carved out of acrylic sheets and coated with synthetic materials with foamy compound substances sprayed onto them from the inside.

Acrylic hot tubs are extremely popular because they come in all shapes and styles and are highly-priced; starting at $3,000 to $4,000.

Fiberglass and ABS layers are often added below the acrylic shells for more reinforcement.

Some exorbitant models are layered with thin slices of steel to prevent cracks. They can be as a 7-8 people empty unit will weigh between 900 to 1,200 lbs and that will be heavy for a deck when your tub is entirely occupied; around 3,000 lbs.

4. Roto Molded

Also known as polyethylene tubs, these are formed with plastic molds and are lighter than acrylic. A regular 4-7 people unit weighs from under 200 lbs to about 450 lbs when empty and around 2,000 lbs when full.

Their strong and lightweight characteristics make them an ideal option for placing on a deck. Their price ranges from over $2,000.

Their strong and lightweight characteristics make them an ideal option for placing on a deck. Roto-molded hot tubs range from over $2,000.

How Much Weight Can a Deck Hold?

How Much Weight Can a Deck Hold

The weight-bearing capacity of a deck can come to be real puzzling at times but luckily; there will always be a rule of thumb.

Take the lengths, sizes and spacing of joists, beams, supporting posts, fasteners, and design into account maintaining all the codes of construction.

In case you are a DIYer or want support online to build a new deck, you can calculate your deck load here.

Pro tip: Load of your hot tub will be concentrated in one spot. Make sure to add enough support posts under that particular area to match with your tub since the weight will not stretch out in most cases.

2 Steps to Reinforce an Existing Deck for a Hot Tub

  • How to add a beam?

An additional beam in between every two previously installed beams will help your deck with its load capacity.

Disperse the deck boards from the selected spot and set the beam in connecting your joists. This might get tricky if the joists are more than 16” away from each other.

You can add patio stones under deck blocks or put in some screw piles around the joists.

There’s one thing you don’t want to do with your existing deck is to dig footings underneath.

You can, however, carefully dig a few footings to reinforce some posts when the deck is not high enough from the ground.

  • How to add a post?

Getting underneath an existing deck and putting a bunch of support posts in place will be hard and troublesome.

The solution is to evenly level the topsoil underneath your beams to add the adjustable post holders, patio slabs, posts, or deck blocks.

This process will not be as efficient as a new beam will be, but it’ll surely increase your deck’s capacity to some extent.

What Impacts a Deck’s Load Capacity?

  • Deck’s time of life
  • Category of planks used
  • Amount of fungus, mold, and deterioration
  • Arrangement of joists
  • Dimensions of beams, joists, and support pillars
  • Groundwork condition

How to Make a Deck Strong Enough for a Hot Tub?

Extra support beams

When you doubt your existing deck that it can’t pull off all the weight of a hot tub full of water and people, you need to add some accessory support beams in between the existing ones.

Concrete slabs

You might as well try out a few concrete slabs, deck blocks, support holders, and any other such suitable items to reinforce your deck.


1. Can my balcony support a hot tub?

Ans: In short, yes! As long as your balcony has a load capacity beyond 100 lbs per square foot. If you’re renting the property and you have no idea how your balcony was constructed, try to get the blueprint of the structure to be sure.

2. Can a Trex deck support a hot tub?

Ans: Yes, Trex decks are a kind of composite deck and often handle more load than traditional wood ones. Make sure that the hot tub’s weight is distributed evenly; and you’ll be just alright.

3. Can you put a hot tub on a condo patio?

Ans: Generally, you can place your hot tub in any condo or apartment. But it’s a good idea to have a structural engineer examine your spot.

4. What is the smallest hot tub you can buy?

Ans: The 71”x 26” bestway Saluspa Miami inflatable hot tub, 4-person Airjet spa is one of the smallest portable hot tub models you can get for around $500. You can go for other similar hot tubs under $1,000.

About the author

Kai Michel

Hello, this is Kai, addressing homeowners in need of some help with their home renovation projects. I’ve worked on numerous toilet repair projects over the years that incorporated a wide variety of tasks, from repair to renovation and maintenance. Besides acquiring a degree on the legal codes and procedures, I gathered vast insights into bathroom settings, toilets, showers, fittings, and other household appliances, fixtures, and components. This helps me guide my clients through their home improvement and interior development plans. Since maintenance is my area of expertise, I can assist people in all phases of the actual ‘improvement’ process. To get my messages even further, I contribute to this site through my blog posts. Check my content here for expert suggestions!

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