The spa pad can be made of pressure treated lumber, synthetic lumber, concrete, bricks or cement patio blocks. A solid cement pad should be no less that 4 inches thick. This is something that the average homeowner may not want to tackle. The spa pad should be at least the size of the spa.
A hot tub requires a stable surface — whether it's a concrete slab, reinforced deck, or firmly compacted soil with crushed gravel. There's also the option to have the hot tub installed in the ground but that still requires a concrete vault.
For most DIY concrete slabs, the best material to use is a ready-mix crack-resistant concrete mix like QUIKRETE. A concrete base for a spa should be around 4 inches thick. This means that for an 8'x8' spa pad, you'll need enough concrete to fill 21.33 cubic feet (that's 36 80-lb bags of QUIKRETE).
The concrete base needs to be a minimum of 4 inches thick (ideally 6 inches) so it is able to withstand the weight of the hot tub.
They said one week is the MINIMUM; they said it takes up to 28 days for the concrete to completely cure, so they recommend 28 days before putting something really heavy (like a hot tub) on it.
Although a slab made of multiple blocks is acceptable, a single slab is preferred because it is more durable. Usually a concrete slab made to building code is suitable to hold a hot tub. However, many patios and other concrete slabs are pitched for drainage, which may make an unsuitable base for your hot tub.
Concrete is strong and provides enough support to your hot tub, which weighs a tremendous amount. People who opt for a concrete foundation typically have the concrete poured as part of a patio, but it's possible to have a slab of concrete poured specifically for your hot tub if this is the option you like the most.
A concrete surface is an excellent base for your hot tub as this material is extremely sturdy and long-lasting. If you have an existing patio made of concrete bricks, make sure it's in good condition and is level (not angled for drainage). A customized poured concrete pad is an even better choice.
Short answer is: Yes. Gravel is an excellent base for hot tubs because it allows for drainage of water while being sturdy enough to handle the high weight of a hot tub.
If you're having a base installed especially for your Hot Tub we would recommend a patio, decking area or poured concrete base. Whatever you choose make sure whoever installs it for you ensures the base is level and large enough for your Hot Tub and steps.
Average Cost To Pour Concrete
To pour a typical 10x10 concrete slab will cost $670 to $930, a 12x12 slab for a patio will cost $796 to $1,476, a 20x24 driveway slab runs between $1,440 and $3,360, and a 24x24 slab for a garage will cost $3,058 to $5,944.
While it only takes around 28 days to cure concrete, drying can take months. The general rule of thumb is that concrete takes about 30 days to dry for every one inch of slab thickness.
The strength of concrete is measured in pounds per square inch (PSI) and is a measurement of the concrete's ability to carry loads or handle compression.
Ensure this outdoor space has level ground with proper footing. Swim spas require a concrete pad that is at least 6″ thick.
There are many different types of foundations suitable for spas but the one that is highly recommended is a reinforced concrete slab that has a minimum thickness of 4''.
Concrete, when applied using the shotcrete process, or cast-in-place, needs to cure for 7 days. Water is the best curing method (7 continuous days).
The forms or “molding” that holds the concrete in place until it dries should be left alone for at least two days to ensure that the concrete is completely dry. If the forms are removed too soon, the concrete can begin to sag, crack and collapse, especially if conditions like temperature affected its strength.
You should wait at least two days before you remove your frame and an additional 28 days before you place your hot tub on the slab to ensure it is dry and stable.
Hot tubs are heavy even without having water in them. A large hot tub full of water can weigh upwards of 2 tonnes, so a suitable level base is vital. The most common base is a concrete foundation.
With an in-ground hot tub, you can enjoy the relaxation and comfort of a spa while elevating your backyard landscape. But can you install a portable hot tub in the ground? Absolutely! With proper planning and preparation, you can create a custom spa look with the therapy of a portable spa.
In most cases getting the hot tub into the backyard is fairly simple and straightforward. A delivery crew will bring the hot tub to your home and then place the hot tub on its side on a hot tub cart. Then they roll the cart into your backyard and to the spot you would like the hot tub placed..