Leviathan Wooden Pergola 4m x 3m | As Seen on ITV Love Your Garden | 120mm Posts | Smart Seal | Nationwide Installation

Leviathan Wooden Pergola – 4m x 3m | As Seen on ITV Love Your Garden

📺 As featured on ITV’s Love Your Garden — the nation’s favourite garden transformation programme, and the show that chose the Leviathan Wooden Pergola to create a stunning outdoor space on national television.

The Leviathan Wooden Pergola 4m x 3m by Dunster House is the pergola that means business. Four metres wide and three metres deep, it delivers a genuinely substantial outdoor living space — large enough to entertain properly, defined enough to feel like a room, and built with the imposing 120mm x 120mm upright posts that give the Leviathan its unmistakable presence.

This is the sweet spot of the Leviathan freestanding range. Wide enough to zone into separate areas — a dining end and a lounge end, or an outdoor kitchen along one side — but perfectly proportioned for most UK gardens without overwhelming the space. It’s the pergola that garden designers reach for when they want impact without excess.

Built by Dunster House from slow-grown, pressure treated spruce — not cheap pine — with every rafter pre-cut, pre-notched, and planed to precision. All timber is fully pressure treated (not merely dip treated) and finished with Smart Seal timber sealant as standard, providing a superior barrier against moisture and UV damage. Backed by a 10-year guarantee against rot and insect infestation.

🌟 Professional nationwide installation and Smart Seal timber treatment are both included in the price, free of charge. Our experienced fitting teams cover the whole of Mainland UK — handling everything from delivery to final fitting.

Key Features

• 📺 As seen on ITV Love Your Garden — trusted by the nation’s leading garden transformation programme
• ✅ Generous 4m x 3m rectangular footprint — the perfect balance of space and proportion for most UK gardens
• ✅ Imposing 120mm x 120mm upright posts — heavyweight structural strength and premium visual impact
• ✅ Slow-grown spruce, not cheap pine — denser grain, superior long-term durability
• ✅ Fully pressure treated (not dip treated) — long-term rot and insect resistance
• ✅ Smart Seal timber treatment included as standard — superior moisture and UV protection
• ✅ 10-year guarantee against rot and insect infestation
• ✅ Pre-notched, pre-cut, planed rafters — precision engineered for a clean, professional finish
• ✅ All fixings included — no hidden extras
• ✅ Perfect for climbing plants — 4m of rafter span ideal for roses, wisteria, and jasmine
• ✅ Nationwide installation included as standard — anywhere across Mainland UK, free of charge

Specifications

• Approximate Size: W4m x D3m (W13'1" x D9'10")
• Upright Posts: 120mm x 120mm
• Timber: Slow Grown Spruce (Fully Pressure Treated)
• Timber Finish: Smart Seal (included as standard)
• Guarantee: 10 Years against Rot and Insect Infestation
• All sizes quoted are nominal. All fixings supplied. Rafters are pre-cut, pre-notched, and planed.

Why Choose Bespoke Oak and Slate?

At Bespoke Oak and Slate, we supply and install premium Dunster House garden structures across the UK — the same structures trusted by ITV’s Love Your Garden to transform outdoor spaces on national television. Every Leviathan order includes professional installation and Smart Seal timber treatment as standard — completely free of charge. No hidden costs, no surprises.

Frequently Asked Questions

Was this pergola really featured on ITV Love Your Garden?

Yes — the Leviathan Wooden Pergola by Dunster House was featured on ITV’s Love Your Garden, the nation’s favourite garden transformation programme. It was chosen by the show’s team to create a stunning outdoor living space — a testament to the quality, visual impact, and versatility of the Leviathan range.

Does the price include installation?

Yes — professional nationwide installation is included in the price, free of charge. Our experienced fitting teams cover the whole of Mainland UK. The price you see is the price you pay — fully installed, no extras.

What is Smart Seal and is it included?

Smart Seal is a premium timber sealant that provides a superior protective barrier against moisture penetration, UV damage, and weathering — going beyond standard pressure treatment to keep your pergola looking and performing at its best for longer. Smart Seal is applied as standard with every order, free of charge, by our installation team as part of the fitting process.

Do you install anywhere in the UK?

Yes. We install anywhere across Mainland UK at no extra cost. Whether you’re in the South West, the Midlands, Scotland, or anywhere in between — our teams will come to you.

Why is the 4m x 3m the most popular size?

The 4m x 3m hits the sweet spot for most UK gardens — wide enough to zone into a dining area and a lounge or outdoor kitchen, but proportioned to sit comfortably in a typical garden without dominating it. It’s the size that garden designers and programmes like ITV Love Your Garden reach for when they want maximum impact in a real-world setting.

How does the 4m x 3m compare to the 3m x 3m and 5m x 3m?

The 4m x 3m sits between the two — offering more space and zoning potential than the 3m x 3m, while remaining more proportionate for typical UK gardens than the 5m x 3m. It’s the most versatile size in the range and the one most commonly chosen for entertaining-focused outdoor spaces.

What makes the Leviathan different from cheaper pergolas?

The Leviathan is a Dunster House product built from slow-grown spruce, not cheap pine, with 120mm x 120mm posts, full pressure treatment, Smart Seal finishing, and precision pre-notched rafters. It’s the pergola trusted by ITV Love Your Garden — and that’s not a coincidence.

What is the difference between pressure treated and dip treated timber?

Pressure treatment forces preservative deep into the timber fibres under pressure, providing long-lasting protection from the inside out. Dip treatment only coats the surface and offers far less protection over time. The Leviathan uses full pressure treatment plus Smart Seal as an additional protective layer — backed by a 10-year guarantee against rot and insect infestation.

Can I grow climbing plants on this pergola?

Yes — the 4m span and open rafter design are ideal for climbing plants such as roses, wisteria, jasmine, clematis, and ivy. Over time they create a spectacular natural canopy across the full width of the pergola, adding fragrance, shade, and a beautiful living element to your outdoor space.

Does this pergola need planning permission?

In most cases, a pergola of this size falls within permitted development rights and does not require planning permission, provided it meets standard conditions. We recommend checking with your local planning authority to confirm your specific situation before installation.

What is the guarantee?

The Leviathan Wooden Pergola 4m x 3m comes with a 10-year guarantee against rot and insect infestation on the pressure treated timber, provided the care instructions supplied by Dunster House are followed.