Osmo 420 UV Protection Oil Extra

From £36.09 (inc VAT) £30.07 (ex VAT) per litre

Osmo UV Protection Oil Extra offers an added layer of protection against harmful UV rays particularly on vertical cladding surfaces exposed to the sun which can cause discolouration, greying and blackening of wood. The Extra formula also contains active ingredients to protect against algae, mould and fungal decay.

Please note: Osmo UV Protection Oil Extra can only be used on vertical cladding surfaces.

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  • Product Name: Osmo 420 UV Protection Oil Extra
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Osmo 420 UV Protection Oil Extra

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At a Glance

  • Sizes: 750ml / 2.5 litre.
  • Enhanced UV Protection for existing finishes or as a standalone finish.
  • EXTRA - provides protection against algae, mould and fungal decay.
  • Suitable for vertical exterior wood applications such as cladding, doors, fencing and furniture.
  • Provides a satin-matt, clear finish.
  • Easy to apply, can offer up to 4 years maintenance-free service.

As a microporous finish, Osmo UV Protection Oil allows the timber to breathe, eliminating the chance of the finish cracking, peeling, blisters or flaking. The natural oils penetrate deep into the wood, keeping it flexible and preventing the wood from drying. 

Osmo UV Protection Oil is easy to apply, and maintain, with no sanding or priming required before or during application. Osmo UV Protection Oil can provide maintenance-free service of 3 to 4 years, depending on the exposure to direct sunlight and water. 

The oil is suitable for a range of products, including exterior vertical cladding and siding, doors, windows, garden furniture, fencing, screens, garden offices, summer houses, pergolas and more. 

Osmo UV Protection Oil is free from biocides or preservatives, offering a safe finish for humans, plants and animals when dry. 

Also available - UV Protection Oil - offers same UV protection without active ingredients to protect against algae. 


  • ThermoWood - prone to grey very fast and therefore application is recommended within the first two weeks after processing.
  • Cedar - new or sanded, requires at least 12 weeks exposure to the exterior elements before application.
  • Larch - new or sanded, requires at least 6 weeks exposure to the exterior elements before application.
  • Pressure-Impregnated Pine - new or sanded, requires at least 12 weeks exposure to the exterior elements before application.

After the weathering period, it is generally recommended to de-grey the surface with a suitable product (eg Sansin Wood Cleaner or Owatrol Net-trol) and clean the surface from the extractive content before application.  Always trial apply before use.    


Natural products

Osmo uses food safe, natural ingredients for the basis of their wood finishes, waxes and pigments, including sunflower, soya, linseed and thistle oil, which is good for customers and wood alike.

Osmo products contain disaromatised white spirit to ensure finishes spread easily, removing the need for so-called "Green solvent" materials which can cause allergies.

Natural beauty of oils and waxes

Wood is a natural material, the cell structure, similar to our skin, can take on and release moisture, it breathes. To ensure that this exchange is not prevented we have created finishes especially suited to the character of the wood.

Osmo natural wood finishes are based on oils and waxes, the oil penetrates into the wood surface, protecting from deep within. The waxes form an elastic, micro-porous surface which protects the wood from external influences. The wood remains naturally beautiful, protected and durable.

Size Price per Tin Equivalent Price per Litre
750ml £25.79£30.95 £34.39£41.26
2.5 litre £75.18£90.22 £30.07£36.09

Coverage / Maintenance

  • Number of coats recommended: 2.
  • Drying time (to touch): 12 hours.
  • Time to re-coat (between applications): 12 hours.
  • Usage: vertical exterior wood surfaces: doors, windows, carports, timber cladding, balconies, fences and pergolas.
  • Recommended application: for best results wood surface must be clean, dry and frost-free (moisture content max. 20%).

Please note:

UV-Protection Oil is recommended only for vertically structured timber (drip angle min 10°) to enable the rain to drip off rather than staying on the wood's surface for prolonged lengths of time.  

Over application and/or low ventilation can increase drying times.

Approximate Coverage

18 square metres per litre with one coat on smooth wood.

Coverage will vary depending on the type of wood, age and surface texture.

Application & Maintenance Advice

Number of coats required

As a final top-coat - 1 coat is required.

As a stand-alone finish - 2 coats required.


Ensure the surface is dry and clean from loose fibres, grease, dust and dirt. 
Do not thin or dilute.
Stir well before use.
Do not sand prior to application.

Application Instructions

Apply a thin and even layer, following the wood grain with a brush or roller, spreading well.

Allow good ventilation while drying - approximately 12 hours.

If a second coat is required, apply as above.  1 coat is ordinarily sufficient when applying on top of an existing finish.

Recommended application amount is approx. 55ml/m².


Depending on the level of weathering, apply 1 coat of Osmo UV Protection Oil every 3 to 4 years and a clean and intact finish. Please note maintenance period can be shortened depending on climatic conditions and how exposed the material is to direct sunlight.

No sanding required

Osmo natural wood finishes can be simply recoated without the need for sanding. This also allows for users to touch up small areas quickly.


UV Protection Oil is unsuitable as a stand-alone finish for decking.

For ingredient-rich wood species (such as Cedar), please allow a minimum of 12 weeks exposure in situ to the outside elements prior to application. 

Please be aware, the high oil content of Osmo UV Protection Oil shows a light-yellowing effect when used on white stained surfaces. In this instance, Natural Oil Woodstain White is recommended. 

Treat any damage or cracks from everyday wear and tear in the finish immediately with two coats.

For full protection against timber weathering, cracking, swelling and shrinkage, use with Osmo End Grain Wax to seal the end grain of the wood.

Exceptional Coverage

Containing a high quantity of pigments and oils, Osmo wood finishes leave a stunning surface finish after just one or two coats, without the need for a primer or base coat.

This means you can achieve near to double the square meter coverage with just one tin compared to an ordinary finishing system.

When It comes to the Osmo paint range, no pre-priming is required, saving time and money.

Courier Delivery


Woodcare, fasteners and accessories.


Up to 3 working days.


£5.00 (ex VAT) for mainland UK deliveries.

£12.75 (ex VAT) for Highlands & Islands.

£18.25 (ex VAT) for Northern Ireland, Isle of Man, Isle of Scilly.

£23.25 (ex VAT) for Isle of Wight.

Free delivery is offered on orders over £100 + VAT to UK mainland postcodes only.

You can view our detailed delivery charges and services here.