As a hygroscopic material, wood absorbs and releases moisture from its surrounding environment.

These changes in response to humidity levels can cause warping, shrinking and cracking. Prolonged exposure to water accelerates this process and, if wood stays consistently damp, creates conditions for wood-decaying fungi to thrive.

Not all woods react equally, however.

The most water-resistant species tend to share some key traits: natural dimensional stability to limit moisture-related movement, a dense grain structure to slow water intake, and naturally-occurring compounds (called extractives) that inhibit decay.

All of the water-resistant woods featured here are commercially available in the UK, so whatever your project, you’ll be able to get your hands on the right wood.

We will start with exterior options, followed by interior choices.

The best water resistant woods for outdoor projects

Ideal for cladding, decking, fencing, garden structures and outdoor furniture.

1. Iroko

Iroko goes by the name ‘African teak’, and it performs similarly at a fraction of the cost – it is dense, dimensionally stable, durable and finishes well.

The wood is a mainstay boatbuilding, testament to its water resistance. It has a dense grain structure and naturally-occurring oils, which help to prevent moisture from penetrating the wood.

Another well-earned moniker for iroko is the Rolls-Royce of decking, with the wood also commonly used for fencing and outdoor furniture.

Many tropical African hardwoods offer great outdoor performance, but iroko’s strong commercial availability makes it a go-to high-performance choice for large projects.

Raised wooden deck with grooved planks beside a beige house, stone wall corner and sliding glass doors; gravel ground and countryside beyond.

Outdoor poolside deck with a curved white wicker sofa and gray and purple cushions, a wooden round table with chairs, lush hedges, and a blue-tiled pool.

2. Ipe

Ipe ('ee-pay') is to mahogany as iroko is to teak – a commercially available, similarly water-resistant alternative to a very expensive wood.

Also known as Brazilian walnut, like mahogany this species hails the Americas. The wood has a luxurious colour palette and truly remarkable strength – it is one of the world’s densest hardwoods.

This density, along with the wood’s tight grain and natural oils, prevent moisture from penetrating the wood.

These properties all mean ipe is another fine choice for decking, fencing and outdoor furniture.

Sunlit wooden pool deck with long planks; a slatted wooden bench/railing on the left and a blue pool edge at the top, casting a shadow.

Red-brown wooden deck attached to a modern glass-walled home, with white wicker chairs around a table; large stones beneath.

3. Oak

A time-honoured construction timber, oak is popularly used for outdoor furniture, cladding, decking, timber-framed garden structures, construction and even boat frames.

Oak’s water resistance can be explained by two factors: density and extractives.

European oak and American white oak both dry to densities around 675kg/m³ and 755kg/m³, making it difficult for water to penetrate the grain.

High levels of tannins, the naturally-occurring substances that resist moisture and decay, give it strong stability in wet environments.

Species of oak (especially European) generally finish very well, which can further enhance its outdoor performance.

Colour variation is a hallmark of oak. Expect a timeless light tan to medium golden brown.

Close-up of timber roof framing with diagonal braces, featuring a black cylindrical device mounted on a vertical post beneath the eaves.

Wooden gazebo with seating under a tiled roof sits in a garden, surrounded by curved pod structures, green lawn, mulch beds, and colorful shrubs.

4. Western red cedar

Visually and technically outstanding, western red cedar is go-to cladding and fencing timber.

Whilst this Pacific Northwestern softwood’s low density and scratch resistance makes it less popular decking and furniture applications, it has abundant extractives that protect the wood from moisture, insects and fungal attack.

The wood has an exceptionally low shrinkage factor, resisting moisture-driven movement well.

Since the wood is pitch and resin free, cedar finishes very well – a semi-transparent stain can enhance its outstanding reddish-brown hues.

Wooden-clad backyard with glass walls, string lights, and potted plants; a blue-tiled pool with a metal ladder in the foreground and seating beyond.

Light gray vertical-slat gate in a horizontal wooden fence, with a black latch. Behind and beside it are green plants, a small path, and a shrub on the right.

Modern wooden home with expansive glass sliding doors, a gray wooden deck, and an outdoor dining area; sunlit garden and trees in the background.

5. Douglas fir

Fir is widely used for structural timber, cladding, decking and joinery.

Despite being a softwood, it has a medium density and is highly resinous, which coats the wood’s cell walls and restricts moisture ingress – dimensional stability that helps the wood avoid movement.

With warm, reddish-brown tones and a straight grain, fir is easy to stain and finish.

Long horizontal wooden slat fence with black outdoor lights, beside a paved path with a gravel border and a green lawn visible beyond.

Night view of a small wooden shed with vertical slats and a glass sliding door; interior desk and chair visible, lit trees along a fence.

6. Siberian larch

A popular softwood for cladding, decking and fencing applications, larch contains natural resins and tannins that resist moisture ingress and slow decay.

Like fir, the species also defies its softwood status with medium density. Its hardiness is due to its slow-growing nature in a very cold environment.

The wood’s strong grain pattern and straw yellow-golden brown hues can make it a characterful, traditional choice.

Wood-clad single-story extension with large glass doors attached to a brick house, under a clear blue sky with a bare yard and concrete slabs nearby. — Uncoated Siberian larch cladding

7. Thermally-modified timber

Thermal modification involves exposing the wood to heat and steam in an oxygen-free environment during manufacture.

This triggers permanent structural changes at a molecular level. Specifically, it alters the hydroxyl groups in the wood’s cell walls (the sites that normally bond with water molecules), dramatically reducing the wood’s ability to absorb water.

This creates a more dimensionally-stable timber, less prone to moisture-driven movement.

The modification process also imparts a stunning darker brown colour on the wood, with many knot-free (clear grade) options available.

Popular commercially-available products for outdoor projects like cladding and fencing include Thermo-ayous, Thermo-pine and Thermo-tulipwood. For hard-wearing applications like decking, look at Thermo-oak.

Brown wooden deck with evenly spaced planks, raised above green grass; dark-framed glass doors are visible at the rear. — Thermo-oak decking

Modern exterior with vertical warm-brown wooden slats, black trim, and wall-mounted lanterns along a row of windows; green trees in the background. — Thermo-ayous cladding

Sealing your wood for outdoor use

For maximum moisture protection and longevity, even the most naturally water resistant wood types can benefit from a finish. Choose a penetrating, non-film-forming product. Depending on your desired look, options include:

Colourless water-repellent oils: Hydrophobic finishes like Owatrol H4 Wood will seal the wood from water. Completely clear, they have no immediate impact on the colour of the wood but will allow the wood to weather naturally to a silvery-grey, whilst protecting from water damage like splitting, cracking and warping. Perfect for the on-trend grey look.
Semi-transparent stains: Great for sealing the wood, retaining its natural colour and helping its natural grain to pop. Owatrol Textrol HES is a powerful oil-based sealant for a matt-sheen finish, available in a range of tints. For a water-based product that leaves a rich, matt finish and stabilises the wood, look at Owatrol Aquadecks.

You might also want to consider a new wood protector, like Owatrol Seasonite. These are designed for wood in its first year of use to prevent damage associated with excess moisture. Water-based and colourless, they prepare the wood for a recoating with another finish after around 6–12 months of weathering.

When applying any finish, we’d recommend using a large, soft bristle brush for the most uniform end result. Rollers, sprayers and drips can be faster, but less consistent.

There are also professional pre-treatment and coating options available when purchasing timber products like cladding, decking and fencing.

Gloved hand with a paintbrush applying stain to wooden deck planks outdoors; a person in a red shirt and jeans stands in the background.

The best water resistant woods for interior use

Perfect for kitchens, bathrooms and anywhere else where moisture, humidity or occasional water exposure is a factor.

1. Iroko (or any teak alternative)

Teak is generally considered the ultimate water resistant timber, but can be prohibitively expensive and difficult to source.

Thankfully, iroko (or ‘African teak’) mimics the wood’s looks and water resistance at a fraction of the cost.

With a dense, interlocked grain and naturally-occurring oils, the species is just as suited to use internally as it is externally – popular for kitchen worktops, window sills, window boards, skirting boards and bathroom furniture.

2. Oak

Oak’s just as at home indoors as it is out.

High tannin content and solid density make it a reliable choice for any flooring, worktops, bathroom furniture, internal doors, staircases or architraves that may experience occasional exposure to moisture.

Both American white oak and European oak are good options and competitively priced, with the latter more widely stocked.

3. Western red cedar

Although typically associated with exterior projects, cedar’s lightweight, water-repellent and anti-fungal properties make for a similarly fine interior water resistant timber.

Great for paneling and lining boards – it is also often applied in saunas.

View project: Yorkshire Hut Co. outdoor cedar saunas

4. Maple

Packing in a dry density of 705kg/m³, maple resists moisture absorption and is very scratch resistant. After a treatment, it’s essentially waterproof.

With its creamy white and pinkish brown hues, it is a pale design-led choice for furniture, flooring and worktops.

Many pieces show unique figure like tiger stripe, birdseye and quilting, adding further character.

Bright modern kitchen with white cabinets, a wooden island, open shelves, bar seating, stainless appliances, and fruit on the counter.

5. Walnut

Incredibly dense, walnut is a fantastic darker option – popular for interior furniture, floors, worktops and bathroom units that might need to withstand some water whilst reflecting opulence.

A well-chosen finish can practically seal it from any moisture-related warping and checking.

Waterproofing your wood for indoor use

Even the most water resistant woods will benefit from sealing with an appropriate wood oil. Products containing danish, linseed, teak and tung oil are popular choices for a beautiful, high-performance finish.

Many internal wood finishes will have a mixture of oil, polyurethane and mineral spirits to improve the application process and drying times. Follow the manufacturer’s guidelines for the best result.