How to Insulate a Shed | Garden Shed Insulation Guide & Tips

Have you noticed that your shed gets too cold in the winter and too hot in the summer? If so, there’s one solution: installing insulation.

For the DIY approach, learning how to insulate a garden shed is key – and that’s exactly why we’re going to teach you. In this guide, we’ll weigh all types of insulation by price and effectiveness to help you get started!

Key takeaways:

  • Insulating wooden sheds can keep the inside warm in the cold season and cool in warmer months.
  • The insulation process can be done at a low cost with a few quick hacks and a reliable guide like this!
  • To do so, you need to deal with all points of its thermal envelope. This includes the walls, floors, windows and doors.

Keep scrolling for step-by-step instructions on how to insulate a shed. (Or check out our short video explainer below.)

Shed Insulation as the ‘Protective Clothing’

As the weather changes, you might start to think about how to prepare your shed for winter. The best way to ensure your garden building stays homely year-round is by insulating it. However, if you’re new to DIY projects, you may not know much about insulation. Here’s what you need to know:

Insulation is a material that helps keep heat from escaping an enclosed space. Insulation sheets reduce the amount of heat transfer between the in and out of the structure. Thus, when insulating a shed, it retains warmth inside even during the colder months – and cooler in summer. The result? A more comfortable and even indoor temperature, no matter what season it may be.

How does it work?

To explain further, insulation will slow excessive heat transfer from your wood shed. It traps air between thick layers of materials and covers any crack where it could escape. An example of this is the gaps around windows.

Adding a layer of insulation isn’t only limited to sheds. The same applies to wooden garden structures, such as a log cabin and summer house. Also, for other outdoor building materials, including plastic and metal.

Why insulate a garden shed?

It’s especially crucial for timber as the material is prone to moisture build-up. Without proper insulation, the panels will invite both cold and hot air in, plus moisture. This also limits the functionality of your storage building at a certain time and season.

But with the right insulation, it’ll prevent warm air from drafting out through the floor. You can be confident your shed will stay productive throughout winter. This also enables you to transform it into a functional garden office, for instance.

Types of Insulation Materials

There are different types of insulation materials available. It’s important to choose an appropriate type based on your specific needs to get the desired results.

Man in a white t-shirt installing mineral wool insulation
Image Credit

Plywood and Polystyrene (Pallet and foam boards)

If there’s one word you want to bear in mind when insulating a shed, it’s Celotex. This insulation board comes in either polystyrene or plywood with foil backs. You can use Celotex boards to insulate all areas of your shed, including:

  • Beneath the roof cladding/in-between roof joists
  • Beneath a concrete or timber floor
  • In-between wall studs


The plywood boards offer a layer of plywood at about £50 a sheet (2.4m x 1.2m), which will bulk up your shed walls. This added width will also slow down heat transfer and insulate your shed.

You can also purchase smaller Celotex boards for about £16 a board (in the same size). Whether you opt for insulation boards, Celotisex is easy-to-install and versatile. Although being a more expensive option than other materials, it won’t break the bank.

Bubble wrap

A sheet of inflated bubble wrap
Image Credit

Yes, that’s right – you can use bubble wrap to insulate a garden shed. But we’re not suggesting you take your standard packing from your last Amazon order.

Instead, opt for foil-backed insulation bubble wrap. This can be tacked to the inside of your shed wall with a staple gun. Or fitted between the wall and an MDF or plywood panel to create a false interior wall.

Bubble wrap contains gaseous air pockets, meaning that atoms have more space. Because of this, they heat more and move slower.

This method of insulating your shed will run you approximately £17 for a 0.6m wide, 8.4m long, by 3mm thick roll. It’s by far the cheapest option, but it won’t deliver the effectiveness as other thicker materials. That being said, it’s still an adequate shed insulation option.

To install bubble wrap in your shed, simply:

  1. Measure the shed’s actual panel and cut the bubble wrap to fit.
  2. Overlap the wrap strips to avoid heat escaping through any gaps.
  3. Staple or tack the wrapping to the shed.
  4. Place a sheet of MDF boarding over the panel and screw or nail into place.

Top tip: Attach the bubble wrap to the wall studs of the shed and not the actual panel itself.

Mineral wool or fibreglass insulation

Fibreglass wool and mineral wool are both extremely well-suited for insulating a garden shed. Fibreglass is used often in new builds as well, however, it’s a bit of a nightmare to work with. It’s itchy and can cause damage to your eyes or throat if it comes into contact with either.

Instead of fibreglass, we’d encourage you to use mineral wool insulation because it’s:

  • Just as easy to install between studs and joists.
  • Denser than fibreglass wool.
  • Great for acoustic and thermal insulation.
  • More fire-resistant than fibreglass.
  • It doesn’t itch as much!

To use fibreglass wool batts or mineral wool batt insulation, simply:

  1. Cut open bags and let the batts expand.
  2. Place the wool insulation in between wall studs or roof joists. This can depend on where you’re insulating.
  3. Cover with plaster, MDF, etc.

Top tip: Protect yourself! Cover your eyes with safety glasses, your nose and mouth with a mask, and wear protective gloves.

Now, let’s move on to where to use these popular insulation materials in your shed!

Cartoon house cross-section with thermal envelope and direction of heat

Thermal Envelope

A building’s thermal envelope is basically all points at which heat can leave your garden shed. By combating these (especially the roof and floor), you can make your shed:

  • More energy efficient.
  • Perfect for year-round use.
  • Better equipped to protect tools and equipment stored within them.
  • Even suitable for use as a garden office!

So, let’s look at how to tackle each point of your shed’s thermal envelope.

Wall (Wall insulation)

The walls of your shed actually account for one of the smaller amounts of heat loss. On average, around 24% compared with around 40% of heat loss occurring through the roofing. With that, it’s crucial to look at your internal and external wall panels.

If you want more than one layer of insulation, your best bet is Celotex boards or Rockwool. Hold them in place with a plywood or plaster wall, depending on your budget and shed size. Use a simple silicone gun or spray foam insulation as an effective solution to fill in any cracks.

BillyOh Master Tongue and Groove Apex Shed in a grassy garden
BillyOh Master Tongue and Groove Apex Shed

Ground (Floor insulation)

The floor surface can leech up to 40% of your shed’s heat. To combat this, Celotex panels between your floor joists before you add flooring can help.

A breathable membrane can also provide underfloor insulation. First, use a builder’s plastic sheet to prevent moisture from coming up through your flooring. Then you can think about floor insulation.

Now, what about insulating shed floors that are already in place? There are two ways to ensure that heat gets retained in your plastic garden storage shed, for instance.

  • Lining the floor with a breathable membrane.
  • Laying a rug or another piece of cloth (like a section of carpet) on top.

Top tip: Suppose you don’t add a breathable membrane. Make sure you regularly check under the rug to see that no dampness or rot is building up.


You want your roof to not only reduce heat loss but also be water-resistant. This is where installing roof insulation felt comes in handy. Not only will roof felt help to prevent dampness and rot, but it’ll also allow for adequate water runoff.

To better insulate, you can install insulation batts or Celotex boards on the roof joists. For metal sheds, seal any gaps with silicone caulk.


With wide double-door sheds, such as this reverse apex shed, you might be losing your mind about how to keep heat in your shed. For doors, the cheapest insulation option is just to keep them closed. You can also use a draught excluder and put up double glazed glass for doors with windows.

Remember to still aerate your shed, though, even in the colder months. If you don’t have vents, you’ll need to ensure proper airflow through your shed to combat any buildup of damp.

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Windows and doors are the most common entryways for water coming into your shed and for heat coming out. To increase the effectiveness of your windows, opt for double-glazed glass. There are a couple of ways to prevent this:

  • Apply a hardening foam filler alongside the edges of the windows and any gaps in the door frame. You can also use mineral wool for this.
  • Keep windows closed!
  • Invest in thicker glazing.

Top tip: Shed heat insulation will also provide noise insulation. If you’re going to use your shed as a workspace, use fibreglass, as this will provide better noise insulation.

Moisture Control

Moisture build-up can cause just as many problems as a poorly insulated shed. One, moisture-caused water ingress or damp items in your shed can wreak havoc. To combat dampness, think about installing a moisture barrier.

To see whether you need a vapour barrier between your shed’s walls or roof, check out the infographic below:

Use this infographic to decide if your wooden shed needs a vapour barrier. And if you want more information about preventing dampness in a shed, check our “How to Damp Proof and Insulate a Garden Shed” guide.

Does my shed need a vapour barrier Garden Buildings Direct infographic with three tiles for different sheds and climates with icons and arrows regarding air flow, insulation, and vapour barriers

How Much Should You Insulate a Garden Shed?

The amount of insulation needed depends on where you live and the intended use of your shed. For extremely cold regions, R-values equivalent to 60 or higher are often recommended.

Should You Hire a Professional or Do-It-Yourself?

Again this decision also depends on different factors. These include the complexity level involved in the chosen wiring plan, for instance. If properly researched and well-prepared, you can install low-voltage electric heating systems. But seeking professional advice first is always recommended.

Insulate a Garden Shed: Rounding Up

After reading all that, we’ll bet you’re now an expert on shed insulation! Let’s quickly recap those different types of insulation as well as their best and worst bits:

  • Celotex insulation boards are efficient and easy to install but aren’t the cheapest.
  • Bubble wrap is by far the cheapest insulation option, but it isn’t as effective.
  • Fibreglass wool is an efficient insulator but can cause you harm without proper safety equipment (it’s also pricey!).
  • Mineral wool is just as good as fibreglass but is cheaper to buy and doesn’t have any added health risks!

You’re all set to start insulating! Or, if you’re ready to invest in a garden shed sale, Garden Buildings Direct is your one-stop shop. For year-round use, we recommend our pressure terated sheds. Check out our range of options for more via the button below!

What’s next on your reading list: Metal Shed Insulation: What Type of Insulation Is Best?

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One of the cheapest forms of shed insulation is bubble wrap. Air pockets will trap and slow down the transfer of heat. You can also buy foil-backed insulation bubble wrap for garden buildings. Otherwise, use a draught excluder and rugs and keep doors and windows shut when not in use.

Yes, insulation can be installed in your shed at all points of its thermal envelope (flooring, walls, and roofing). Insulation methods range from caulking and expanding foam in gaps and around window frames to using insulation batts and boards.

To insulate a small wooden shed we suggest weighing up how important it is to do so and what your budget is. Make sure to seal and gaps in the roof and walls and if need be, consider installing some insulation batts for a cheap solution.

If you want the most comprehensive insulation installed whilst building your shed, we encourage the use of Celotex insulation boards. Although slightly more expensive than insulation batts, they are less prone to water damage and longer-lasting.


Use an energy-efficient radiator or tubular heater on a low, constant setting.

Yes, insulating a shed will slow down the transfer of heat exchange. That means it'll stay warmer in winter and cooler in summer, especially if you close its thermal envelope and use a fan or air conditioning.


See the infographic below to determine whether your shed needs a vapour barrier between the roof or walls. A breathable membrane underneath any garden building's flooring is always a good idea.


Does my shed need a vapour barrier Garden Buildings Direct infographic with three tiles for different sheds and climates with icons and arrows regarding air flow, insulation, and vapour barriers
Use this infographic to decide if your wooden shed needs a vapour barrier.

Yes, an inexpensive way of insulating a garden shed (somewhat) is to tack bubble wrap to the wall panels.

Disclaimer: Please note that this guide is intended to present general information regarding garden sheds for sale. All information indicated are representative and not exhaustive, which means that the results may vary depending on your item, its size, complexity and other circumstances.