How To Insulate A Garden Shed | Step By Step Instructions

Summerhouse Mancave Insulation For Your Garden Office

Everyone who spends an extended amount of time in their garden gym, office, shed, or summerhouse will know the importance of keeping it insulated & warm. Comfort ability is a key component of creating an atmosphere that you want to spend time in, and this is where insulation comes into play.

Here is a quick summary of the key takeaways from this guide: 

  • If you want to stay warm in the winter you should consider insulating your shed.
  • You should insulate your shed the moment the shed is ready for insulation to be put in place.
  • You need to choose the right material to insulate your garden gym shed otherwise it’s practical use will not be what you need it to be. Some materials are very easy to install, some materials are very resistant, and some materials are expensive. It is entirely up to you what you choose, you just need to have in mind what best suits you, your budget & your uses.
  • Guides On How To Install Floor, Roof & Wall Insulation For Your Shed.

Step 1: Picking The Right Material

Insulation Garden Gym Shed, Flooring, Walls & Ceiling
Insulation For Your Garden Gym Shed

Your first step in insulating your garden gym shed is picking the right material. It’s important you pick the right material so that the shed can function properly for the job that you intend to use it for. You may also want to check out our guide on the best home gym flooring ideas

Types Of Insulation:

Tongue And Groove 

This is made up of a lot of wooden planks. These wooden planks fit together, however this can take a lot of time to install. Tongue & Groove does look very good & will add a great aesthetic look to your garden shed.

One drawback to using tongue and groove insulation is it’s very expensive. A shed made from this excellent insulating material will have an amazing heat resistant property about it, resultantly meaning you may save money in the long term.


Is great insulation if you’re on a budget. Plasterboard is very easy to install, you can install it with nails and glue. It’s very practical and adds a lovely contemporary feel to your garden shed. However if you’re looking for something more aesthetically pleasing, plasterboard might not be your best option.

Breathable Membranes:

Breathable membranes are great for waterproofing your garden gym shed. Additionally, if you do not have shed ventilation the air permeability this.

It’s important to have ventilation in your garden shed, for example if you were to make a gym in your garden shed the air would become very thick with sweat, moisture and germs. As a result of this your garden gym would stink, no one wants to be constantly smelling sweat whilst they’re working out, which is why it’s essential to have good ventilation in your garden shed.  

Bubble Wrap:

Is the most cost-effective way of insulating your shed. Bubble wrap is the closest thing you can get to being able to insulate your shed for free. If you’re on a tight budget this is a perfect option for you as easily obtained from any store.

The only problem with using bubble wrap as insulation is it’s not a great insulator, despite the fact it is very cost effective. However it is better than using nun at all and you should consider using it in conjunction with another insulating material for great results.

Fibreglass Roll:

If you like saving the environment, a fiberglass roll is perfect for you. If you’re a DIY experienced man or woman, who knows how complicated DIY can be, this option is an amazing quick and easy DIY job which you will love.

Fiberglass has plenty of air pockets within it, which makes it a great long-term investment as it will not need replacing often. This will save you a lot of money, however when it is wet you need to be careful as it will lose its insulating properties. Another thing to be cautious about is that it can contain properties, which if they are inhaled, can result in damage to your lungs. We suggest that you put an insulation board over fiberglass to prevent harm. 

Step 2: Laying Down The Flooring

Flooring To Insulate Your Garden Gym Shed Fitness Center
Picking The Right Flooring For Your Garden Gym Shed

Now, assuming that you have picked the correct Flooring for your garden gym gym shed it is time we now move on to how you can lay down this flooring so you can start using it as soon as possible.

If you have only just got your shed the best way that you can prevent heat from escaping is by laying under floor insulation.

This is also a considerable option if you have the time to remove your shed flooring & replace it because you would like insulation.

How To Lay Under Floor Insulation:

  • Put Wooden Blocks Under Each Joist Cavity
  • Make Sure Each Cavity Has At Least Two Support Blocks
  • Set Up A Table Saw, Or A Handheld Jigsaw
  • Measure & Cut Your Chosen Insulation So It Can Fit Between Your Floor Joists.
  • Layer Insulation Flush To The Top of The Joists

How To Insulate A Shed Floor (without Under Floor Insulation):

  • Measure & Cut A Breathable Floor Membrane, This Will Allow Some Ventilation Through The Floor of Your Shed.
  • Lay It Over Your Shed Floor.
  • Cut Your Chosen Insulator To Size (we recommend that you use something easy to install, like carpet)
  • Lay Down Your Chosen Insulator.

Which insulator you choose is entirely up to you & again, depends on your uses or budget for your garden shed.

How To Insulate Your Shed Roof & Walls:

insulate your garden gym shed roof & fitness center
how to insulate your garden gym shed roof

Now you’ve insulated your shed floor, you’re ready to start on the roof & walls. Luckily for you, the process of installing each is very similar. It is important to remember that the very best garden sheds will use a standard roofing felt.

  • Measure Each Gap Between The Wall Panels
  • Cut Your Chosen Insulator & Breathable Membranes To Fit The Size Of Each Wall Panel.
  • Lay Down Your Breathable Membrane Over The Wall / Roof Panels, With The Insulator Of Your Choice On Top.
  • Place An Oriented Strand Board (OSB) Over Each Panel & Staple Them Into Place. 

Make Sure You Do A Proper Job! 

It doesn’t matter whether you have an office, a gym shed or a summerhouse in your garden you need to make sure that it has been properly insulated. No one wants to be unable to use their garden building in the winter  because they didn’t fully insulate it. Or even worse, fully insulating their garden building in the winter.

If your shed’s walls are thin, make sure you put a thick layer of insulation, if the shed is big, make sure you use more, it is all relative to the size of the shed & the thickness of the walls, use your common sense. Remember that heat rises from the floor & will be lost through the roof, so make sure you take extra time & be extra attentive to insulating these parts of your garden building.