Wood-Fired Hot Tub Inserts – Fiberglass & Acrylic Liners 

At Gardenvity, we design every insert for durability, comfort, and timeless beauty.
Explore the materials, colours, and sizes available for your perfect wood-fired hot tub.

Stylish Colour Options

Ergonomic Design

Premium Materials

Sustainable Craftsmanship

Materials: Fibreglass vs. Acrylic

We offer two insert options —  acrylic and fibreglass— each with distinct advantages.

Acrylic Inserts

Acrylic is a durable, high-gloss material often used in premium bathtubs and spa manufacturing for its strength, clarity, and luxurious finish.

They’re thermoformed from thick sheets of sanitary-grade acrylic and reinforced with multiple layers of fibreglass for rigidity and durability. Compared to fibreglass, acrylic offers better UV protection and higher scratch resistance, keeping its glossy look for years.

Deep, mirror-like gloss finish

Superior resistance to scratches.

Retains warmth longer, improving heating efficiency

Fibreglass Inserts

Fibreglass (also known as GRP – Glass Reinforced Plastic) is a lightweight yet incredibly strong composite material.


It’s crafted by layering glass fibres with high-grade resin and finished with a gel coating for a smooth, glossy surface.

 

However, compared to acrylic, fibreglass surfaces can be slightly more prone to fine scratches, which is natural for this type of material and doesn’t affect performance or comfort.

Excellent strength-to-weight ratio

Cost-effective without sacrificing quality

Although acrylic inserts are often associated with premium aesthetics, modern fibreglass technology has advanced so much that it’s now difficult to spot the difference in appearance and smoothness.


Fibreglass liners are exceptionally strong and reliable — this material is widely used in yacht and marine manufacturing, proving its outstanding durability and water resistance.

Colours: From Luxurious Marble to Modern Monochrome Shades

Crafting the Marble-Effect Hot Tub Liner

Hot Tub Insert Design – How Heater Type Changes the Interior

The heater type directly affects your Hot Tub’s interior layout and comfort, with each option offering unique benefits to match your space and usage needs.

Standard or Verta Integrated Heater

  • In models with a Standard or Verta integrated heater, the stove is positioned beneath the insert, which creates a raised seating area inside the tub.
  • This elevated spot is perfect when you want to cool down without leaving the water, as it allows you to sit higher while still staying comfortably immersed.
  • It’s a compact and efficient choice, ideal for smaller gardens or limited spaces.

Integrated Horizon or External Heater

  • The external heater is positioned outside the Hot Tub, while the integrated Horizon heater is built inside the tub’s structure. Both options keep the entire interior smooth and spacious, without any raised sections.
  • This design maximises seating comfort and provides more usable space inside the tub.
  • However, it requires slightly more garden space to accommodate the external heater next to the tub (unless you choose a model with the Horizon integrated stove, in which case this does not apply).

Hot Tub Insert Shapes – Round, Square or Ofuro?

Ofuro Oval Insert – Compact & Intimate

Inspired by the traditional Japanese soaking tub, the Ofuro is smaller in size and designed for two adults or two adults and a child.
It’s perfect for those who don’t need a large tub, but still want the luxury of a private, wood-fired spa experience.
Ideal for romantic retreats, smaller gardens, or vacation properties, where a compact size adds both charm and practicality.

Round Insert – The Classic Choice

A round insert gives your hot tub a traditional, timeless appearance.
Its circular shape naturally brings people together, creating a friendly atmosphere where everyone faces each other — ideal for social bathing and family moments.
Round tubs fit beautifully in most gardens and feel instantly familiar.

Square Insert – The Modern Upgrade

The square shape offers a sleek, contemporary design with a bit more interior space.
Its straight lines and wider corners provide extra legroom, making it perfect for those who value comfort and a stylish, modern appearance.
It also integrates beautifully into modern outdoor settings or structured garden layouts.

Sizes, Shapes & Capacity – Find the Perfect Fit for Your Hot Tub

Whether you prefer a round, square, or oval shape, Gardenvity has the perfect size for your space and lifestyle.

Round 

 Integrated STANDARD / Integrated VERTA HEATER

4-6 person

Inner diameter: 180 cm

Round 

 Integrated STANDARD / Integrated VERTA HEATER

6-8 person XL

Inner diameter: 200 cm

Round 

External / Integrated HORIZON heater

4-8 person

Inner diameter: 180 cm

Round 

External / Integrated HORIZON heater

6-8 person XL

Inner diameter: 200 cm
Title

Square 

 Integrated STANDARD / Integrated VERTA HEATER

4-6 person

Inner diameter: 180 cm

Square 

 Integrated STANDARD / Integrated VERTA HEATER

6 person

Inner diameter: 170 cm

Square 

External / Integrated HORIZON heater

6-8 person XL

Inner diameter: 180 cm

Oval (Ofuro) 

Integrated HORIZON heater

2 person

Inner diameter: 170 cm

Please note: for ranges such as 4–6 persons, the lower number indicates how many people can enjoy the Hot Tub very comfortably and with plenty of space.
The higher number reflects the maximum capacity, meaning additional people — often children or extra adults — can still join, but the seating will be more compact compared to the optimal comfort level.

Thermal Insulation – Keep the Heat, Save the Energy

Most of our pre-configured hot tub models already include thermal insulation as part of the standard setup (however, always check each model’s component list for details).

If you’re configuring your hot tub from scratch, we strongly recommend adding thermal insulation to your selection — it provides a clear improvement in both comfort and efficiency, especially during colder months.

Why It Matters:

Reduces heat loss through the liner walls

Keeps the water warm for longer sessions

Reduces firewood use while maintaining temperature

Improves overall energy efficiency and user comfort

Choosing thermal insulation means less time heating and more time relaxing — enjoy the warmth longer while using less energy and wood.

Ready to create your own oasis?

Turn your dream backyard moments into reality — find the hot tub that matches your style and space.

Start Choosing Your Hot Tub

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