Leviathan Wooden Pergola 2.5m x 2.5m | 120mm Posts | Smart Seal Treated | Nationwide Installation Included

Leviathan Wooden Pergola – 2.5m x 2.5m | 120mm Posts | Smart Seal Timber Treatment

Don’t let a compact garden hold you back. The Leviathan Wooden Pergola 2.5m x 2.5m by Dunster House proves that big impact doesn’t require a big footprint. With its commanding 120mm x 120mm upright posts and precision-engineered framework, this pergola brings genuine architectural presence to even the most modest outdoor space — creating a defined, beautiful garden feature you’ll enjoy for years.

Picture lazy summer afternoons beneath the open rafters, a climbing rose weaving its way up the sturdy posts, the scent drifting across your garden. The Leviathan is the kind of structure that transforms how you use your outdoor space — turning an ordinary garden into somewhere you actually want to spend time.

Crafted from slow-grown, pressure treated spruce — not cheap pine — every component is denser, stronger, and built to last through the British seasons without complaint. 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 — we handle everything so you can simply enjoy your new pergola from day one.

Key Features

• ✅ Substantial 120mm x 120mm upright posts — premium strength and visual weight
• ✅ Slow-grown spruce, not cheap pine — denser grain, superior 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 finish
• ✅ All fixings included — no hidden extras
• ✅ Ideal for smaller gardens — big pergola presence in a compact 2.5m x 2.5m footprint
• ✅ Perfect for climbing plants — posts and rafters designed to support roses, jasmine, and more
• ✅ Nationwide installation included as standard — anywhere across Mainland UK, free of charge

Specifications

• Overall External Dimensions: 2.30m x 2.30m (7' 6" x 7' 6")
• External Width: 2.13m (6' 11")
• External Depth: 2.13m (6' 11")
• Internal Width: 1.83m (5' 11")
• Internal Depth: 1.83m (5' 11")
• Overall Height: 2.33m (7' 7")
• Internal Eaves Height: 2.12m (6' 11")
• 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. Every Leviathan order includes professional installation and Smart Seal timber treatment as standard — completely free of charge. No hidden costs, no surprises — just a beautifully installed, fully sealed pergola ready for you to enjoy.

Frequently Asked Questions

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.

Is this pergola suitable for a small garden?

Absolutely — the Leviathan 2.5m x 2.5m is specifically designed to deliver maximum impact in a compact footprint. At just 2.30m x 2.30m externally, it fits comfortably in smaller gardens, patios, and courtyard spaces while still providing the substantial 120mm post presence the Leviathan range is known for.

What makes the Leviathan different from cheaper pergolas?

The Leviathan is a Dunster House product built from slow-grown spruce, not cheap pine. Slow-grown timber has a denser grain structure, making it significantly stronger and more durable. Combined with full pressure treatment, Smart Seal finishing, 120mm x 120mm posts, and precision pre-notched rafters, the Leviathan is in a different class to budget pergolas.

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 layer of protection — which is why it comes with a 10-year guarantee against rot and insect infestation.

Can I grow climbing plants on this pergola?

Yes — the Leviathan’s 120mm x 120mm posts and open rafter design are ideal for climbing plants such as roses, jasmine, clematis, wisteria, and ivy. Over time, climbing plants can create a beautiful natural canopy, adding fragrance and shade 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 (e.g. not covering more than 50% of garden area, not positioned forward of the principal elevation). We always recommend checking with your local planning authority if you are unsure.

What are the exact dimensions?

The overall external footprint is 2.30m x 2.30m (7' 6" x 7' 6"), with an internal space of 1.83m x 1.83m. The overall height is 2.33m (7' 7") with an internal eaves height of 2.12m (6' 11"). All sizes are nominal.

Are all fixings included?

Yes — all fixings needed for assembly are included at no extra cost. As installation is included as standard, our professional team handles the entire build for you.

What is the guarantee on this pergola?

The Leviathan Wooden Pergola 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.

How does this compare to the Leviathan Diamond Corner Pergola?

The Leviathan Wooden Pergola 2.5m x 2.5m is a freestanding, open-sided structure designed to sit anywhere in your garden as a standalone feature. The Leviathan Diamond Corner Pergola is designed specifically to fit into a garden corner, with a distinctive diamond roof design and a larger 3m x 3m footprint. Both share the same 120mm post specification, pressure treated spruce construction, and Smart Seal finish.