Best Cedar Cladding Oil for Garden Studios: 2025 Expert Review
DR Joinery
Expert Joiner & Timber Specialist
Western Red Cedar is the gold standard for cladding garden studios and summerhouses. It offers natural resistance to rot and decay, which is essential here in York where the damp can linger. However, homeowners often don't realise that 'rot-resistant' doesn't mean 'colour-fast'.
Without a quality UV-resistant oil, that beautiful amber-red timber will turn a silvery grey within a year or two. Whilst some favour this weathered look, letting the timber dry out too much can lead to splitting and cupping, especially on south-facing walls.
In this review, I'm focusing on Treatex oils. I've used various brands on site, but Treatex creates a finish that penetrates deep into the grain rather than sitting on top like a plastic film. Whether you need a sample to test the colour, a clear oil to maintain warmth, or a grey tone for a modern aesthetic, here are my top recommendations.
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Specs vs. The Real World
The Spec: "Usage Claims"
"Many tins claim 'one coat protection' is sufficient for exterior timber."
In my experience, especially on the thirsty end-grain of cedar, one coat creates a patchy finish. You always need two thin coats for proper UV stability and water resistance.
The Spec: "Maintenance Free"
"Cedar is often sold as a 'maintenance-free' timber."
Structurally, it is very durable. Aesthetically, it requires maintenance every 2-3 years if you want to keep the original colour. If you leave it, it will grey unevenly.
My Top 3 Recommendations
Three options to cover different needs and budgets
Treatex Exterior Cedar Oil 30ml Sample Pot
Treatex
Before committing to a large tin, I always advise clients to test the oil on an offcut of their actual cladding. This sample pot allows you to see exactly how the oil interacts with the specific batch of timber you have, ensuring you're happy with the finish before spending more.
The Good
- Low cost way to test colour compatibility
- Prevents expensive mistakes on large areas
- Allows testing of absorption rates on your specific timber
The Bad
- Only sufficient for a small test patch
- Cost per litre is high due to small packaging
Installer Tip:
Apply this sample to a scrap piece of cedar, not the main wall initially. Let it dry for 24 hours to see the final colour, as wet oil looks different to cured oil.
Priced at £6.50 at the time of writing
Check Price on AmazonTreatex Exterior Cedar Oil 31380H 2.5 LTR
Treatex
This is the standard I use for most garden studios where the client wants to retain that warm, vibrant cedar look. It is highly water-resistant and contains UV inhibitors that slow down the bleaching process significantly. It penetrates well without peeling.
The Good
- Excellent penetration protecting deep into the grain
- Microporous finish allows wood to breathe (crucial for cedar)
- Enhances natural grain without looking plastic
The Bad
- Requires re-application every 2-3 years depending on exposure
- Strong odour until fully cured
Installer Tip:
When applying this to T&G (Tongue and Groove) cladding, ensure you brush the oil into the 'V' grooves first. If you just roll over the face, the grooves stay dry and become arguably the first place for water ingress and discoloration.
Priced at £66.72 at the time of writing
Check Price on AmazonTreatex 31385 Exterior Grey Cedar Oil 2.5Ltr
Treatex
This grey-tinted oil is fantastic for two specific scenarios: clients who want that contemporary 'weathered' look immediately without the patchiness of natural ageing, or for disguising older cedar that has started to turn silver unevenly. It unifies the appearance instantly.
The Good
- Provides immediate uniform colour
- Hides water marks better than clear oil
- Offers higher UV protection due to added pigment
The Bad
- Masks the natural red/amber tones of the wood
- Can look solid/painted if applied too heavily
Installer Tip:
Stir this tin thoroughly and often. The grey pigments settle at the bottom very quickly. If you don't stir it every 10-15 minutes during use, the last bit of cladding you paint will be a much darker grey than the start.
Priced at £65.69 at the time of writing
Check Price on AmazonFrequently Asked Questions
How often should I oil my cedar cladding?
Can I apply cedar oil over wet timber?
Is Treatex suitable for chemically treated 'softwood' decking?
Why has my cedar turned black even though I oiled it?
Do I need to sand the cladding before re-oiling?
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