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Forest Log Cabin Garage vs Gillies & Mackay Garage

This post is supposed to be a comparison pitting a G&M Garage against a Forest Log Cabin garage. Forest Log Cabins have popped up on our radar a lot recently, with customers asking questions about how the two building types compare. 

However, I can’t write that blog post, for the simple reason that these two product types are not comparable. They’re not the same. They’re not built the same, they don’t cost the same and they don’t perform the same. 

We’ve discussed this issue in the past – focussing on Tuin Log Cabins – but it’s worth repeating. You don’t want to find yourself lumbered with a sagging, water-damaged building when you were expecting decades of solid protection.

So what are the differences between a Forest Log Cabin garage and a Gillies & Mackay Garage?

Should I buy from a manufacturer or a supplier?

Every one of our review blogs covers this important topic. If you want reliable, expert feedback on your building once it’s in place, buy it from a manufacturer. 

Nobody knows your Garage like the people who designed and built it. If there are any issues with your building, you can go back to the manufacturer and ask for their advice. 

When you buy from a supplier like Forest Log Cabins, you’re not dealing with the people who made your building. You’re dealing with people who buy these buildings from the manufacturer and sell them to you. 

They may have some knowledge of the construction based on their experience installing the buildings. But they simply don’t need the same level of expertise that a manufacturer has. 

Suppliers deal with multiple models and product types – far too many to be experts in each one. They simply don’t know the buildings they sell as well as the people who build them.

How is a log cabin built?

Log cabins tend to fit into one of two categories: they’re either classic log cabins or interlocking log cabins.

What is a classic log cabin?

A classic log cabin built by Grant Gillies of Gillies and Mackay.
A traditional log cabin built by Grant Gillies, our co-founder and former Canadian cabin-builder.

Classic log cabins are really rare on this side of the Atlantic. They are part of a long-established tradition of cabin-building. Highly skilled experts with an in-depth knowledge of the craft create these unique buildings. As well as the skills required to build a classic log cabin, you also need to stay on top of the high level of maintenance.

What is an interlocking log cabin?

An interlocking Forest log cabin garage.
A Forest Log Cabins garage – a typical interlocking log cabin building

Interlocking log cabins allow you to access a similar aesthetic to classic log cabins without the associated expertise and costs. These buildings slot together like jigsaw puzzles. Each log is the same length and breadth as the building. This single layer of timber stacks up to form the walls.

Constructing an interlocking log cabin is relatively easy, and they’re often self-assembly buildings.

What are the drawbacks of log cabins?

As the linked video above shows, classic log cabins are beautiful, traditional buildings which require a whole lot of maintenance. Even with all the love, care and attention that’s lavished on this building, the owners acknowledge that it’s a lot of work keeping their cabin semi-watertight.

And interlocking log cabins face many of the same issues. Timber movement causes gaps between logs, compromising the integrity of the structure. This movement also causes the building to go out of square, which compounds the problems of water ingress. 

Why should you have your building installed by a professional?

What do I mean by “go out of square”? Let’s get our geometry on and take a look!

Think about putting a lid on a box. The lid is a certain shape and size so that it fits the box. If the box changes shape and loses its 90° corners, the lid won’t fit anymore. 

In this analogy, the walls are the box, and the roof is the lid. When a building is out of square, the corners are no longer at 90°. The building’s carefully designed construction no longer works, because that construction was engineered to work with 90° corners. If this changes, the building won’t be as successful as it was designed to be.

Now multiply this analogy by every single joint and angle in your log cabin. If the walls aren’t square, the roof doesn’t fit properly. When the roof isn’t square, it doesn’t fit the walls. If one joint isn’t exactly the angle it’s designed to be, it impacts all the other joints.   

This is why we always recommend having your building installed by an expert. Getting the building perfectly square is a tricky job if you’ve never done it before. Every single joint matters to the others, and this precision requires a high level of skill and experience. 

But even if it’s installed perfectly, with every joint exactly correct, a log cabin can still change shape.

How does water impact log cabins?

As with any single-skinned timber building, there’s always the potential for timber movement and water ingress. 

Timber is porous, meaning that it can absorb water from the air around it. If there’s a lot of moisture in the air, timber expands. If there’s more moisture in the timber than the air, it moves out of the timber and the timber contracts. 

The breathable properties of timber are actually really useful. They ensure that your building can cope with atmospheric changes better than garages made from less natural materials. They also help prevent condensation inside timber buildings.

But they also come with some drawbacks.

Timber copes best with slow, gradual changes in temperature and moisture. It wants a stable, predictable climate, where the seasons heat up and cool down slowly and regularly. Most timber buildings will experience minimal movement in these conditions. 

But this is Scotland. We experience wild swings of temperature and unpredictable rainfall patterns in a single day sometimes, never mind in an entire season!

Because interlocking log cabins are made from thick timbers, it’s less likely that water ingress will happen due to moisture penetration. It’s not impossible, but it’s more likely to happen because of shape changes to the timber itself. 

What type of timber are log cabins made of?

A screenshot of the Bertsch Holzbau website, showing a navigation menu and an interlocking log cabin

If you’re new around here, you might not be aware of my low-key obsession with timber. 

Buying a timber garden building to stand in a Scottish garden? You must find out what type of timber it’s made from.

Not that this is easy. In fact, it can be downright impossible

Bertsch Holzbau are the German manufacturer who supply Forest Log Cabin garages. This product brochure states that they make their buildings from “Northern European Firs.” they also refer to “Nordic timbers from Sweden or Norway.” 

Northern European fir was a new one for me. The vast majority of timber garden buildings are made from either spruce or pine, with the odd larch outlier here and there. 

So I put my research hat on and took a look at Northern European fir.

What is Northern European Fir?

A screenshot of a Google search for Northern European Douglas fir, showing no results.

I found a whole lot of information about Douglas fir, which is native to the US, and very commonly used for interior framing and exterior uses like decking. Douglas fir is a strong softwood that’s naturally resistant to water. If Bertsch Holzbau are making their log cabins out of Douglas fir, then they’ve made an excellent choice in their materials. 

However, neither their brochure nor their website mentions Douglas fir. This seems strange, as Douglas fir is a good-quality timber for exterior use. If they’re using Douglas fir, they should be shouting about it. 

But if you Google “Northern European fir,” you’ll find results that refer to Douglas fir and Silver fir. There are roughly 48-65 species of fir, and the timber of each has different properties. But since Bertsch Holzbau isn’t specifying what sort of fir they’re using, they’re not really telling us anything. 

Next, I discovered that the term “Northern European Douglas Fir” isn’t one that timber merchants or suppliers use. In fact, Google found exactly zero results for this term.

So Bertschz Holzbau uses “Northern European Fir” on the first page of their brochure, implying that this is something praiseworthy. But actually, this term doesn’t mean anything and doesn’t tell us whether or not these buildings are worth your time and money.

Why is it so unusual for timber building companies to talk about timber types?

Are you a timber expert? I’m not, although I certainly know a whole lot more about timber now than I ever thought I would. 

To assess the quality of timber here’s the information you need: the species of tree it comes from, and the country the tree grows in. 

You should also consider which part of the tree the timber is milled from, but if you’re shopping for a timber building, the first two points generally give you enough information to decide whether or not a building is good value for money.

What does the timber expert say?

A large stack of Scandinavian Redwood timber weatherboard, ready for cladding a Gillies & Mackay timber garden building.

Fortunately, G&M does have a resident timber expert – horticulture specialist John Mackay, one of our founding directors. So I asked John about this confusing term: Northern European firs.

He told me several very interesting things:

  1. This is a blanket term for a variety of coniferous species of tree. John pointed out that this is like saying “a loaf of bread,” without giving any further information about what type of bread it is. If the species isn’t included, this term doesn’t communicate any useful information.
  1. The generic term “fir” often encompasses spruce. This doesn’t make any sense, as while the two species are both conifers, fir and spruce are different trees which produce very different timber. But John’s absolutely right – there are timber suppliers using fir and spruce in the same listing to refer to the exact same piece of timber. 
  1. Douglas fir doesn’t grow particularly well in Sweden and Norway. It’s better suited to warmer climates and doesn’t cope well with frost. While there are some plantations of this species in both countries, the timber isn’t notable enough for timber merchants to specify where it’s from. The best Scandinavian timber species are spruce (whitewood) and pine (redwood).

All of this is an extremely detailed way of saying that I don’t know what sort of timber Bertsch Holzbau log cabins are made of. And when timber building companies are evasive or misleading about this very straightforward piece of information, I assume one thing, and so should you: they’re using spruce.

Is spruce a good timber for building log cabins?

In short, no. Now, Scandinavian spruce is way better than British spruce. But it’s still spruce, and the main reason that spruce isn’t a good idea for exterior applications is that it’s very susceptible to shape change when exposed to moisture. 

Spruce is an excellent timber for indoor applications, and there’s absolutely a place for spruce within a layered timber building. But in a single-skinned exterior structure, it’s not a good shout.

Most interlocking log cabins available on the British market are made of spruce. 

Now, here’s where things get complicated. Norwegian spruce is the best spruce available, but it’s not better than Scandinavian pine heartwood. This is taken from closer to the centre of the tree and takes in much less water than pine sapwood. In terms of problems with moisture and water ingress, Scandinavian pine sapwood is the most likely to cause issues, Norwegian spruce is slightly better than pine sapwood, but Scandinavian pine heartwood is least likely to change shape and cause problems.

Can you see why timber building companies can get away with providing spurious, evasive and downright misleading information about the timber that they’re using? And that’s not good enough. You deserve to know what you’re getting when you buy a timber building.   

What happens to a log cabin when the timbers change shape?

A screenshot of an article on Timmersol.com, showing gaps and timber movement in interlocking log cabins
From Pete’s article, showing some of the problems that interlocking log cabins face.

Exposing timber (especially spruce) to moisture causes shape changes like bowing, cupping and warping. If every piece of your interlocking cabin is designed to be perfectly square, you’re going to have problems when that’s no longer the case.

It’s like the analogy with the box and the lid, but the entire garage is built of boxes whose lids no longer fit!

This excellent article on the Timmersol website has clear photos of the problems that happen when the timbers of a log cabin garage change shape due to exposure to moisture.

What I really like about this article is that Pete, the author, is really responsive to comments and questions. And do check out the comments. They feature issue after issue with interlocking log buildings, caused by the construction methods and moisture-related shape changes that I’ve pointed out here.

Do log cabin garages have any other problems?

One other thing to consider about timber movement due to moisture is the movement of windows and doors. If you have double glazing in your log cabin garage, you may think that this will help keep the water out. However, it doesn’t matter how reliable the double-glazing units are – if they’re placed in a wall that changes shape the frames won’t stay flush with the wall, and water will have yet another way of getting in. 

This is a common issue that’s also discussed in the Timmersol article comments section.

Should you buy a Forest log cabin garage?

Am I saying that no one should ever buy a Forest Log Cabin garage? Of course not. I’m not here to tell people what to do. I’m here to make sure that everyone has enough information to make an informed decision.

If you don’t mind water getting into your building, a log cabin garage might be exactly what you’re after. But if you need a fully watertight structure to protect a valuable classic car or other expensive equipment, a log cabin garage isn’t a reliable choice. 

As Pete points out in his Timmersol article, you can help reduce the chances of water getting into a log cabin garage by regularly treating the timbers with a specialist preservative. But this isn’t going to eliminate water ingress, just limit it. You’ll have to take your chances.

Interlocking log cabin garages aren’t watertight. Because of the materials and construction methods used, variations in the quality of their installation, and how much moisture they’re exposed to, they’re extremely likely to let in water.

What’s the alternative to a Forest Log Cabin garage?

An apex Gillies and Mackay timber garage painted grey with matching grey garage door and personnel door.

If you’re looking for a traditional timber aesthetic but you’re worried about water ingress, we’ve got you covered.

Gillies & Mackay Garages simply aren’t like other timber garages on the market.

They’re fully Building control-compliant, solid, watertight structures that do not let water in.

What is Building Control?

If you’re building a structure to live in, you must follow Building Standards regulations, which are legally enforced by the Building Control process. These regulations ensure that the building is fit for habitation – it’s constructed in such a way that it won’t let in water, it’s not going to collapse on top of anyone, and it’s safe for humans to live in.

While you’re probably not going to live in a Gillies & Mackay Garage, from a safety point of view, you absolutely could. And in terms of keeping the contents of your garage dry, there’s no safer bet. 

The vast majority of garages we install fall under permitted development rules and don’t need either planning permission or Building Control. But our buildings meet the construction standards for either of these situations.

How is a Gillies & Mackay timber Garage different?

A diagram showing the specification of a Gillies and Mackay timber garage, with each layer labelled.

With a 3-Tier construction including an air cavity and breather membrane, a Gillies & Mackay Garage is for people who want to be sure that they’ll never have to deal with water inside their building. 

The secure tongue & groove profile of the outer layer of cladding minimises moisture-related timber movement and the 3-Tier construction ensures that any movement is limited to this outer layer. Oh, and we use pressure-treated Scandinavian Pine, also known as Scandinavian Redwood, for this outer layer. We’ve got nothing to hide about our building specifications.

This carefully engineered design ensures that moisture doesn’t have a chance of getting into your building, and any windows and doors stay exactly where you placed them when you designed your bespoke Garage. 

Because they’re designed, manufactured and installed by experts, you can put anything you like in a G&M Garage and it will stay safe and dry for decades. 

How do Forest Log Cabin Garages compare to Gillies & Mackay Garages?

Quite simply, they don’t.

One type of building can’t be guaranteed to stay watertight due to poor-quality materials, limitations in the construction method, and an inability to deal with the Scottish weather.

One type of building can be guaranteed to stay watertight due to the best materials available, Building Control-compliant construction, and the ability to triumph over the Scottish weather.

How do the prices compare?

A screenshot of a text box containing the text: Pricing Information. At Forest Log Cabins we have always tried to show accurate prices on our website, unfortunately this has become very difficult over the last couple of years due to volatile timber prices. We simply have too many products on our site now to keep everything showing an accurate price.

I’d love to tell you what sort of budget you need for a Forest Log Cabin garage, but unfortunately, I can’t. There’s a notification on their website saying that they have far too many products to display up-to-date prices for everything. You have to contact them for a quotation. I’m not sure what this is all about – even a ballpark figure would take care of this problem. But from looking at their website, a Forest Log Cabin garage costs somewhere between nothing and a million pounds, I presume.

You can find indicative prices for a Gillies & Mackay Garage here. These are guidelines and the final price will depend on exactly what you choose for your custom design. But they give you a clear breakdown of how much every aspect of the project will cost. The final decision on which features you include is entirely up to you.

I assume that a Bertsch Holzbau-supplied Forest Log Cabin garage is significantly cheaper than a Gillies & Mackay Garage because they’re not in any way the same quality of product. Hotdogs don’t cost the same as fillet steak. 

If your budget allows for a log cabin garage, you have to be prepared for the amount of maintenance needed. You shouldn’t expect that the building will stay watertight. This means being careful about what you store in your garage. You must regularly look out for signs of water damage, mould and rot, and check window and door frames to ensure that no movement has taken place.  

Should I choose a Forest Log Cabin garage or a Gillies & Mackay Garage?

A large Gillies and Mackay apex timber double garage with natural coloured timber, a grey garage door and a timber carport.

Your choice will depend on your budget and your expectations for your building.

If you don’t mind the limitations of a log cabin garage and don’t plan to store perishables inside, this may well be the best choice for you. If this is the building you can afford right now, be aware that it will need to be replaced in a relatively short period of time.

But if you want a building that you can rely on to stay entirely watertight, that allows you to store anything you like safe in the knowledge that it will stay dry, and which will last for many decades as a result, go for a Gillies & Mackay Garage.
Do you need more information about your garage project plans? Book a Consultation with us so we can get you started thinking about exactly what you need.

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