Featured image for “How to tell if you’re buying a solid shed.”

How to tell if you’re buying a solid shed.

Solid as a rock might be one of the oldest cliches out there. But as far as similes go, it’s a pretty good one. There’s something so trustworthy and safe about the word solid. And when you go shopping for a shed, solidity should be one of the first qualities you look for. But how do you sort a solid shed from a shoddy shed?

How thick should shed framing be?

A close up of the rafters, truss and frame of a Gillies and Mackay wooden shed.

The first place to start is with the specification. As you’ll know if you’ve ever read one of our review blogs, not all shed companies include the specifications of their buildings online. 

This is extremely irritating and usually means a phone call, which is a waste of your time if it turns out their specification isn’t up to scratch. 

But if you do happen upon a website that shares the building specification, the first thing to check out is the thickness of the framing used.

The frame of a shed is the bones of the building. If the framing isn’t solid, your shed won’t be either. For a solid shed, the framing should be at least 40mm x 50mm.

If your shed-maker uses imperial measurements, the framing should be at least 1½  x 2 inches

There’s a little wiggle room included here – if the framing is 38mm x 55mm you’re still within that minimum. Also, if your shed is a big hefty boi with a wall spanning more than three or four metres, the framing should be much thicker than this minimum.

Note that this is a minimum – a really solid shed will use thicker framing than this. You can buy sheds with 70mm x 45mm framing, and this additional thickness makes a huge difference to how solid the shed is. 

Should shed framing be pressure-treated?

Another great feature of shed framing is pressure treatment. A shed salesman recently told me that there is no point in pressure-treating framing, as it’s not exposed to the elements. I didn’t like to tell him he was absolutely blethering, but he was. 

Pressure treatment does make timber resistant to rot, mould and insect damage. This means that it’s far less likely to be damaged by water. (Although this doesn’t mean it’s ideal for keeping water out of a building.)

While the intention when making a shed is to keep water on the outside of the building, a single-skinned shed could be susceptible to water ingress. Water ingress can eventually damage timber. Since the frame is the foundation of your solid shed, a belt and braces approach to keeping it strong and whole is an excellent idea.

And if you’re looking for another marker of quality when it comes to shed framing, ask about the grade of the timber. 

Framing should be either C16 or C24 – C24 framing is what’s used in new-build houses, and if a shed company uses materials of this quality you know that you’re looking at a solid shed.

So remember, for the most solid shed framing, look for:

  • A thickness of at least 40mm x 50mm (thicker is better).
  • Pressure-treatment.
  • C24 graded timber.

How thick should shed cladding be?

A diagram of a panel of timber cladding, showing the tongue and groove profile of the boards.

Ahh, the old cladding question! This is one of the most reliable markers of a cheap shed – the cladding will be like tissue paper. Cheap, mass-produced sheds with 5mm thick cladding are most definitely not solid!

As a general rule, between 16mm and 20mm is best for the Scottish climate. Go for the thickest cladding you can find within this range.

Does thicker cladding make for a better shed?

Interestingly, cladding that’s thicker than 20mm isn’t massively helpful at keeping the weather out. You’re getting into interlocking log territory at this point, and we’ve talked before about the problems seen in those buildings.

The money you’d spend on decent cladding that’s thicker than 20mm would be better spent on a building with layers. Our 3-Tier Sheds are a perfect example of this principle. While these buildings are more expensive, they’re also completely waterproof. With an air cavity and a stabilising layer of OSB, these are seriously solid sheds.

Cladding thickness contributes to the weight of the building, which also impacts how sturdy the building will be. 16mm is the absolute minimum you want if you’re looking for a solid shed.

What roofing material makes the most solid shed?

A Gillies and Mackay apex timber shed painted pale blue. The grey steel box profile roofing is clearly visible.

The problem with roofing felt isn’t that it’s rubbish – good quality roofing felt should last at least ten years. The problem is it’s that it’s hard to tell what sort of quality it is. 

As with many building materials, it can feel like a minefield when you start researching roofing felt. There are different materials used and different weights. Some recommend underlay, some don’t, some are installed with nails, and others with heat.

How do I find the best roofing felt for my shed?

In general, look for the heaviest felt you can find. We used to use 34kg roofing felt before we decided to stop using this material. Shed companies often talk about “heavy duty felt” but don’t specify what this actually means.

While comparing roofing material options is a whole other article, if you pick felt, choose torch-on rather than nail-on. It’s far more stable and will last longer. Check the weight of the felt, as this will contribute to how solid your shed will be.

What’s the best roofing material for a shed?

If you want a really solid shed, choose steel roofing. Our box profile steel roofing has a 20-year manufacturer’s guarantee. We get it from Planwell in Buckie, and there’s nothing like it for keeping the water out of your shed. A dry shed is a solid shed, so choose the best roofing material you can find.

It’s also worth noting that shed roofs should be made of timber. Make sure there’s no plywood or OSB underneath your roofing felt or steel. We love a bit of OSB, but only when we’re absolutely certain that it won’t come into contact with rainwater. 

Timber sarking boards are best for your shed roof. A solid shed has a timber roof, whether it’s finished with felt or steel. It’s quite common for sarking timber boards to be thinner than the shed cladding, especially with a steel roof. Make sure that the sarking isn’t more than a few millimetres thinner, however. 

What sort of floor makes a solid shed?

Would you believe that some sheds come without floors? 

This is a clear sign that you’re looking at a poorly built shed. If you have to pay extra for a shed floor, or it comes as an option, find another shed company.

As with the roof, it’s very common for a shed floor to have thinner (or thicker) boards than the timber used for the walls. But make sure you stay within that 16-20mm range. Anything thinner than this will not contribute to a solid shed.

While the thickness of the flooring is important, so is what’s underneath the floor. A solid shed floor will have a solid timber frame underneath it, between the building and its base

How can I find out this information for myself?

Annoyingly, sometimes the only way you can find out these details is to phone and ask. Now maybe you like a good old natter on the phone, but if you’re a busy human with lots on your plate, you’d probably rather find out online.

Also annoying is when there is a specification, but it doesn’t include the important information that you need. It’s hard to decide if a shed is solid if the specification doesn’t include the framing thickness.

My best advice is that you ask, keep asking, and ask some more. I hope that one day all shed companies will include this basic information in an easily accessible, non-gatekeeping manner. Unfortunately, right now it’s far more common to have to make a phone call to find out what you need to know. 

How can you tell if a shed is solid?

A Gillies and Mackay pent shed painted pale grey. It has double doors and steel box profile roofing, and sits on a patio next to some grass and a hedge on one side and a wooden fence on the other.

And if you’ve checked the specs and you’re pretty sure that the shed you’re looking at is a solid shed, there’s another really simple way to test this theory out.

We call it “The Shove Test,” and it does exactly what it says on the tin. Go and see a building made by the company you’re dealing with, and give it a really good shove. Put all your weight into the building. If the shed is solid (because of its thick framing, weighty cladding and hefty roof and floor) it won’t move. 


If the shed rocks, wobbles, or even MOVES (the horror!) then your shed isn’t solid. Isn’t it lovely when things aren’t complicated?

If anyone objects to your Shove Test efforts, ask them why it’s a problem to give what is supposed to be a solid building a good shove. Any buildings that fail The Shove Test aren’t solid enough for you to consider putting them in your garden, so unless you’re a teeny petite pixie of a human being, this is a pretty failsafe way to determine how solid a shed is. 

Where can I buy a really solid shed?

You’re more than welcome to come and Shove Test our buildings. They’re all on display at our Show Area in Errol, and they’re all extremely solid. Don’t believe me? Check out our shed specifications and you’ll see that the framing, sarking, cladding flooring and roofing are all top-quality, solid timber. 

And if you’d like to know more about which questions to ask your shed company, check out our Shed Buyer’s Checklist. It gives you a clear framework for understanding shed specifications, making sure that you find the best shed you can.

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