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

If you’ve got a wooden shed or perhaps a garden office which you plan to spend a lot of time in, keeping it warm and comfortable is important. The best way to avoid those extreme temperatures and keep it comfy is by installing insulation!

Learning how to insulate a shed is key to making the most of it and enjoying it – and that’s exactly why we’re going to teach you how – both cheaply and easily!

In our quick guide below we’ll be weighing up all types of insulation for your shed by price and effectiveness while telling you how to do it yourself! We also have some great information on making all elements of your shed insulated.

 

Key Things to remember:

  • Insulating your outdoor shed can keep it warm in winter and cool in summer.
  • Insulating your shed can be done cheaply with a few quick hacks, full insulation, or even comprehensively as you build it!
  • To insulate your garden shed, you need to deal with all points of its thermal envelope – that includes the walls, floor, windows, and doors.

Keep scrolling to read our great guide, or check out our short video explainer below:

Insulation

There are many ways you can insulate a shed – but none of them are the “right way”. Each form of insulation that we’ll go through has different pros and cons.

But before we get into that, what is insulation and how does it work?

Insulation will slow down the transfer of hot air out of your garden shed by trapping air between thick layers of material and covering any gaps where it could escape. This means that your shed, log cabin, summerhouse, whatever, will stay warmer in the winter months.

Insulation will also help regulate your shed’s indoor temperature in the summer months.

Insulation Materials and Installation

Below, we’ll go into insulation options before explaining where to use them in your shed and how effective they are. When you’ve finished this guide you’ll have a clear plan of action to insulate your shed no matter what your budget.

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

Plywood and Polystyrene (Foam Boards and Pallet Boards)

 

If there’s one word you want to bear in mind when insulating a shed, it’s Celotex. This type of insulation board comes in either polystyrene or plywood with foil backs that insulate the building.

You can use Celotex boards to actually 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 basically bulk up your shed walls. This added width will slow down heat transfer and insulate your shed, aided by the insulating materials of the foil.

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

Bubble Wrap

A sheet of inflated bubble wrap
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Yep, that’s right – you can use bubble wrap to insulate your shed! Now, we’re not suggesting you take your standard packing from your last Amazon order.

Instead, opt for foil-backed bubble wrap insulation. This can be either tacked to the inside of your shed wall with a staple gun or fitted in between your wooden shed‘s 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 (and heat), move more slowly.

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

To install Bubble wrap in your Garden Building, simply:

  1. Measure the shed panel and cut the bubble wrap to fit.
  2. Overlap the bubble 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 frame (wall studs) of the shed and not the actual panel itself!

there was a video here but i’m removing it

Fibreglass or Mineral Wool Insulation

Fibreglass wool and Mineral wool are both extremely well-suited for insulating a 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 insulation, we’d encourage you to use mineral wool. Mineral wool is:

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

Seriously, for around £18 a batt save your eyes, skin, and wallet the trouble! 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) depending on where you’re insulating.
  3. Cover with plaster, MDF etc..

 

Top tip: Always remember to protect yourself, cover your eyes with safety glasses, your nose and mouth with a mask (you’ll probably have some lying around now!), and wear protective gloves when handling fibreglass wool.

Now we’ve covered some of the most popular materials for shed insulation. Now, let’s move on to where to use them 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 have a look at how to tackle each point of your shed’s thermal envelope.

Wall

The walls of your shed actually account for one of the smaller amounts of heat loss on average, approximately 24% compared with around 40% of heat loss occurring through roofing. That being said, if you want to insulate your garden building properly, you’ll still want to look at your internal and external wall panels.

 

If you want more than one layer of insulation then your best bet is to install Celotex boards or rockwool insulation batts and hold them in place with a plywood or plaster wall (depending on your budget and shed size).

 

You can also use a simple silicone gun or spray foam insulation as an effective solution to fill in any cracks in your shed’s outside walls that might be causing heat loss.

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

Ground

We said just now that your flooring can leech up to 40% of your shed’s heat. To combat this, think about installing Celotex panels between your floor joists before you add flooring.

Also, depending on the floor surface that your shed is built on, you may want to use a breathable membrane to provide underfloor insulation. First, use a builder’s plastic sheet to prevent moisture and even weeds coming up through your flooring. Then you can think about floor insulation.

When it comes to insulating shed floors that are already in place, there are two main ways to ensure that heat gets retained inside your plastic garden storage.

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

Top Tip: If you don’t add a breathable membrane, make sure you regularly check under the rug to see that no damp or rot is building up.

Roof

To properly insulate your shed, you want your roof to not only reduce heat loss but also be water-resistant. This is where installing roof insulation felt, like that included as standard with our BillyOh garden sheds, comes in handy.

Not only will roof felt help to prevent dampness and rot in your roof, but it’ll also allow for adequate water runoff. To better insulate your roof, you could install insulation batts or Celotex boards between your roof joists.For metal sheds, seal any gaps with silicone caulk.

Doors

With wide double door sheds you might be losing your mind at how to keep heat in your shed. For doors, the cheapest insulation option is…just keep them closed! You can also use a draught excluder and think about installing double-glazed glass for any 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

To increase the effectiveness of your windows, you might want to opt for double glazed glass. Windows and doors are the most common entryways for water coming into your shed and for heat coming out.

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 a level of noise insulation. If you’re going to use your shed as a workspace, we recommended using fibreglass as this will provide the best noise insulation.

 

Moisture control

As we mentioned just now, moisture build-up can cause just as many problems as a poorly insulated shed. Moisture-caused water ingress or damp items in your shed can wreak havoc. So to combat damp, 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.

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

And if you want more information about preventing damp in a shed check out this great guide we wrote.

Wooden Sheds vs Metal Sheds

 

Now, it should be mentioned that, although a lot of the methods mentioned can be used for both, they’ve been put forward with wooden sheds in mind.

For example, insulation batts won’t really work in a metal shed where you can’t cover them with MDF or OSB boards. So, if you want to learn more about combating condensation in metal sheds, check out this guide.

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 panels are an efficient and easy-to-install option, but aren’t the cheapest.
  • Bubble wrap is by far the cheapest insulation option, but aren’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, check out our range of options via the button below!

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FAQs

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.