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By Amy Hanlon on 28 Feb 2024

What’s the best timber for a wooden garage?

If you’re shopping for a wooden garage you’re definitely going to have questions. Questions about the price of the building. Questions about the quality of the building. To buy the best timber garage you can, you might think that the first question you need to answer is: what’s the best timber for a wooden garage?

But hold on…

To buy the best timber garage you can, there’s an EVEN MORE important question you have to ask first: How is the garage constructed?

I don’t mean to get all technical (who am I kidding – I LOVE to get all technical!) but before we get to the nitty-gritty of timber, we need to consider the specifications of the building.

What makes a good-quality garage?

A diagram of the Gillies & Mackay timber garage specification.

There are three crucial components to a watertight timber garage: layers, a dampproof membrane and an air cavity. A well-built garage base could be considered the obscure band member who left before timber garages became famous.

Most wooden garages on the market have only a single layer of cladding fixed to a timber frame. They’re built exactly the same way as a shed. And like single-skinned sheds, they are quite good at keeping water out, as long as they’re meticulously maintained. 

But if you’re building a garage to house a precious classic car, or you’re constructing a workshop that will store expensive equipment, do you want a building that’s quite good at keeping water out, or do you want a completely watertight building?

What problems does water ingress cause?

The corner of a painted timber building showing signs of water ingress and mould.

Water ingress in a timber garage is much more problematic than it is in a shed. When a timber building lets in water, the timber it’s made from is susceptible to shape changes like warping and cupping. 

If this happens in a shed you may spring some leaks and find that the door doesn’t close properly. As more water penetrates the building, these problems intensify, eventually leading to mould, rot and structural instability.  

If this happens in a garage those small problems are magnified and have a much greater impact. When larger timbers change shape, larger issues occur. Larger leaks. More water.

And if a shed deteriorates enough that it falls apart, it’s troublesome, but not a huge deal. If a building the size of a garage falls apart, you’ve got a disaster on your hands. 

How does an air cavity prevent water ingress?

Timber is a naturally porous material, even when it’s painted. While pressure treatment is often used as a way to prevent insect damage and rot in wooden buildings, it also makes timber more porous, and therefore more likely to absorb water. 

If you have a single-skinned garage and the walls are absorbing water, this water will eventually end up on the inside of your building. Over time this causes damage, shape changes, mould and eventually rot. The contents of your garage will also mould and rust. 

This is why a vented air cavity is essential in a wooden garage.

When combined with a damp-proof membrane, an air cavity stops water ingress in its tracks. 

Even if water seeps through the outer cladding of the building, the worst that can happen is that this moisture condenses on the membrane. As the cavity is vented, that moisture will evaporate once the outside air contains less moisture. 

If there’s a layer of insulating material between the membrane and the inside of the garage, it’s unlikely that even this will happen, as the insulating properties of both air and the inner wall won’t allow for the temperature difference needed for condensation to form. 

Related Reading:

The Best Timber Garage Specification

How Are Timber Walls Constructed?

Log Cabin Garage vs Gillies & Mackay Garage

As you can see, the calibre of a wooden garage comes down to more than just the type of timber it’s made of. But this is still an important question to ask…

What type of timber is usually used for wooden garages?

Most timber buildings are either built of Spruce or Pine. In the UK, Spruce is often called Whitewood and Pine is often called Redwood.

But it’s a wild world out there online when you’re looking for information about timber. Just take a look at this, taken from Dunster House’s listing for the Deore Garage:

A screenshot of Dunster House website listing for the Deore Garage, showing the product information.

This listing is problematic. It confidently states that this garage is made from Spruce, which is better than Pine. Later it reiterates that it’s made from Slow-Grown Spruce, NOT cheap Pine.

And they may have a point. Spruce grown in a cold, stable climate, like in Sweden, Finland or Norway, is better than Pine grown in a mild, changeable climate like Britain. 

But Spruce is not inherently better than Pine. Good Pine is much better than good Spruce for exterior use. Since the Dunster House listing doesn’t say where the Spruce is sourced from, you don’t have enough information to judge whether or not it’s better than cheap Pine. 

What’s the best timber for a wooden garage in Scotland?

A large Gillies & Mackay apex timber garage stained golden brown, with a dark grey roller garage door.

Scandinavian Pine is the best timber for a layered building with an air cavity that will withstand the weather we see here in Scotland.

Sometimes referred to as Scandinavian Redwood, this timber is slow-grown and naturally far more resistant to shape changes than even slow-grown Spruce.

If your timber building is going to be installed in Scotland – whether it’s a shed, summerhouse or garage – steer clear of Spruce. Pick Scandinavian Pine.

Is Cedar the best timber for a wooden garage?

Cedar is another cladding option that’s used for wooden garages, specifically Western Red Cedar. 

Cedar is a stable softwood that’s naturally more resistant than Scandinavian Redwood to shrinking and shape change. It’s prized for its pinkish-red appearance, and can also be left untreated to weather to a silvery-grey colour.

However, Cedar is an expensive alternative that’s lighter and more brittle than Redwood. This makes it easier to mark and damage. And whether your building uses Cedar or Redwood, it needs an air cavity and membrane to stay watertight.

As with any other type of timber, check which country your garage cladding is sourced from. Canadian Western Red Cedar is infinitely better than British Western Red Cedar, and accordingly, it’s around twice the price. If you’re being offered cheap Western Red Cedar, it’s most likely British, and of lesser quality.

Is Larch the best timber for a wooden garage?

Larch also falls under this very important rule. The best Larch is Siberian, but due to current sanctions against Russia, this timber isn’t available in the UK. 

This means that any Larch garages are likely being made with British Larch, and while it’s admirable to buy British, our climate means that in the case of timber, it’s not the best choice.

Should wooden garage walls be pressure-treated?

The answer to this question very much depends on the construction of the building. If your building is single-skinned, pressure treatment will increase the likelihood of water ingress. 

If your building has an air cavity between the cladding and the internal walls, it’s a great idea to pressure-treat the cladding. You can enjoy the anti-rot and strengthening benefits conferred by pressure treatment without having to worry about water getting into the building. 

What’s the best timber for a wooden garage?

The best timber for a watertight garage with layered walls, a damp-proof membrane and a vented air cavity is Scandinavian Redwood.

If you’re buying a single-skinned garage Scandinavian Redwood is still your best option, but be aware that your building will succumb to water ingress in prolonged periods of wet weather.  Keeping moisture out of your garage is crucial to the longevity of your building, as well as the condition of its contents. Single-skinned garages won’t last as long as layered buildings with a cavity. 

Where can I buy a watertight timber garage?

If you want to find out more about layered timber garages, have a look at our Learning Centre. It has tons of useful content about our buildings and the decisions we’ve made about their specifications. You can also come and see two of our gorgeous Garages at our Show Area here in Errol.

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