
Are you looking for a garden room that’s the envy of all your neighbours, but doesn’t require too much maintenance?
Our Radiata Garden Rooms are one of the newest additions to the G&M family, but have instantly become a customer favourite. Their thoughtful design means they’re fully watertight, in keeping with permitted development, easy to look after and of course, come with a 30-Year Guarantee.
These garden rooms are clad in Radiata Pine ThermoWood, which not only gives them an eye-catching colour but is incredibly durable and long-lasting. As with any timber building, though, these rooms do need some care to keep them looking pretty and living up to their lifespan.
This is your comprehensive guide to caring for your Radiata Garden Room. I’ll cover cladding care, ventilation and other tips and tricks for garden room maintenance.
How do I care for the cladding?
Your Radiata Garden Room comes with a preservative base coat which protects it during transit and installation. Your cladding is naturally protected from moisture, so it isn’t necessary to recoat your building unless you want to retain the original dark brown colour of the timber.
You have two options: leave your Garden Room to weather, or oil it.
Can I leave my Garden Room to weather?
Left untreated, the dark brown timber will gradually change to a pale blond tone, and eventually weather to a silvery grey colour.
Weathering is a completely natural process caused by exposure to UV light and weather. This is a cosmetic change and doesn’t impact the integrity of your Garden Room. This is the lowest-maintenance option for your building, and if you’re happy with these colour changes you don’t have to treat your building in any way.

Can I oil my Garden Room?
If you’d prefer to maintain or stabilise the colour of your timber, oiling is the way to go. You have two approaches:
- Preserve the original colour: apply Osmo UV Protection Oil in shade Light Red Cedar (431) around three weeks after installation, then recoat once a year.
- Let it weather first: allow the timber to reach your preferred tone, then begin the oiling cycle using clear Osmo Oil or Light Red Cedar depending on the finish you’re after.
If your Garden Room has weathered unevenly, a blend of clear and Light Red Cedar Osmo Oil can help standardise the tone. If it’s weathered more than you’d like, Light Red Cedar can be used to darken the timber back down.
Before recoating, we always recommend cleaning the cladding with Osmo Decking Cleaner, following the manufacturers instructions. Beyond that, your building only needs recoating once a year, or whenever you feel it needs a refresh.
You can buy Osmo Oil from Bannermans in Dundee or Perth or online here.

Access our Radiata Garden Room Buyer's Guide
Everything you need to know about Radiata Garden Rooms in one easy-to-digest guide!
Enter your email address below to access your copy.
Should I ventilate my Radiata Garden Room?

Just like you’d open up the windows in your house to air it out, it’s also important to ventilate your timber building.
Most customers choose to position their Radiatas in a sunny spot in their garden. The rooms are very well insulated, so they easily retain warmth. Sitting in direct sunlight in the summer means they can get hot quickly. To protect the interior, it’s important to avoid excessive heat build-up.
We recommend opening up windows and folding back the French doors on hot days when possible. This will get the air flowing and prevent the building from getting uncomfortably hot.
We’d also advise fitting blinds to your Garden Room windows to reduce direct solar gain and keep the room cool. For your window size, the best fit is:
Width: 568mm
Drop: 1306mm
Ingo depth: 40mm
Blinds will help filter sunlight, maintain a pleasant temperature, and add extra privacy to your Garden Room.
During the summer months, another easy way to make sure your Radiata is getting enough ventilation is to use the Openlock feature on the double-glazed windows. This allows air to flow through the windows and into your garden room whilst the window is still securely locked. Perfect for if you’re out at work or away on holiday, but still want to ventilate the space.
Here’s a demonstration of how to use the Openlock feature:
What else can I do to look after my Radiata Garden Room?
Here are a few more tips for keeping your Radiata Garden Room happy that you might not have considered:
Flooring
If you’ve chosen laminate flooring in your Radiata Garden Room, we recommend keeping this clean with a floor wipe mop, rather than a wet mop, to prevent excess moisture from building up in the building.
Adding a large rug is a simple way to protect flooring in high-sunlight areas while also adding comfort, warmth, and style to your space.
Guttering

Best practice for your Radiata Garden Room is to have guttering and a perimeter soakaway that the guttering runs into. Without guttering or a soakaway, any water that flows off the roof will hit the ground and splash up onto the cladding of your building. This excessive moisture can damage the timber over time.
If you’ve opted for guttering on your Radiata Garden Room, make sure to regularly check and clean the gutters to avoid any blockages. This will ensure water can effectively run off the roof, protecting your garden room.
It’s also best to keep any grass, shrubs, or trees trimmed back from the cladding of the building, to prevent moisture getting trapped against the timber. Similarly, we don’t recommend adding window boxes or plants to the side of your building, because the moisture can damage the timber cladding.
Roofing

Depending on the Radiata Garden Room model you choose, it will have either an Isola shingled roof or a steel box profile roof. Both options were carefully selected for their durability, low-maintenance design, and longevity.
The steel has a 20-year manufacturer’s guarantee, while the shingles come with a 30-year manufacturer’s guarantee. Neither of these roofing options requires routine maintenance; simply try to keep the roof clear of debris and trim back any overhanging trees to preserve their lifespan.
How much maintenance does a Radiata Garden Room need?

Now you know how to care for your Radiata Garden Room to keep it looking and performing at its best! Remember that you have the option to recoat the building in Osmo Oil to maintain the timber tone or to leave it to weather naturally.
These small steps will help you get the very best from your Garden Room, protecting all furnishings and finishes while ensuring year-round comfort.
For even more advice on Radiata maintenance, check out our Aftercare Guide.
If a Radiata Garden Room seems like the timber building of your dreams, book a no-obligation Consultation with our Team to discuss your garden room plans in detail.
Come and see these beauties up close at our Show Area in Errol, where you’ll find a Deuchny, Vorlich, Rannoch and Kindrogan on display – which one will be your favourite?









