How to Insulate a Garage

Planning a garage conversion? Or need to ensure the heat of your garage for other reasons? You will need to know how to insulate a garage - here's how!

If you are planning a garage conversion, or simply need to ensure the heat of your garage for other reasons, you’ll need to know how to insulate a garage.

In the UK, garages are usually not heated – they are usually constructed from breeze blocks which don’t keep the heat in and won’t help keep the space cool in summer.

Luckily, insulating a garage isn’t a difficult process once you’re clued up and if you know the reasons you are looking to insulate the space - and the insulation materials you will need!

One of the main reasons people insulate a garage is because they want to convert it into a liveable space, such as a second living room or another bedroom - particularly a detached garage.

Rent out my garage


Join thousands of Stashbee Hosts, start earning now

Rent out my garage

However, another reason to insulate your garage is if you find it is making the room next to it or above it cold. In this case you would insulate the room from the garage rather than the garage itself.

Installing garage insulation means you can continue to use your garage in the winter without worrying about being cold, or convert your garage into another liveable space.  

Whatever your reasoning for wanting to insulate your garage, we have you covered with our guide on how to insulate a garage.

Garage construction

How to Insulate Garage Walls

As mentioned, in the UK, garages tend to be built from breeze block. Not only can this let in the cold, but in rainy Britain that means rainwater can make its way into the walls.

Usually, this isn’t an issue, as when the garage isn’t insulated, the moisture will evaporate. However, if you’re thinking of insulating your garage it could become an issue.

Make sure that your internal walls are not damp before insulating and you’ll be fine. 



Water Damage in Your Garage - What Causes It and 9 Ways to Prevent It

Read article

Now you know your walls are ready for insulation, you need to decide whether to opt for external or internal wall insulation – external has the benefit of leaving you more space to work with but internal tends to be easier and costs less.

There are a few options when it comes to internal insulation:

  •  Fix your internal insulation directly to the wall for easy installation. With this method, you need to be sure your existing walls are in fairly good condition, but you simply use adhesive to glue plasterboards with attached insulation to the walls - this method is easy to install.
  • If your walls are not in the best shape, you can fix battens to the wall and then attach the insulation onto these to ensure you have a gap between the wall and the insulation. This is ideal if you’re worried about damp.
  • Construct a new wall inside the original wall. If your existing walls are prone to rainwater and have suffered significant damage then you may not be able to use them to hold up any insulation. 
  • Use insulating plaster. Another option when it comes to insulation is to use an insulating plaster. It might not provide the same energy efficiency as other methods, but it can save time and money and provide additional heat. 
  • For cavity wall insulation, where it is only one wall that needs insulating – you only need to fill the cavity wall with insulation and won’t have any concerns with moisture or rainwater damage. 
Inside of a garage wall, with hoses attached to it and a sign saying "No parking"

How to Insulate a Garage Floor

Although it seems like the first place to insulate, it’s not just the walls that need insulating – especially if you want to make your garage into another living space. You will also need to consider insulating the garage floor, especially if you need to meet building regulations.  

However, it is expensive to rip up the existing flooring and restart. Instead, you can use a similar method to the walls, and add foam insulation on top of the existing flooring.

The exact thickness of the floor insulation will be calculated based on the ceiling height of the room itself.



Garage Floor Epoxy - What You Need To Know Before Going DIY

Read article

How to Insulate a Garage Roof

Insulating a garage roof is pretty similar to insulating the roof in any part of your home. If it’s a flat roof, you may need to add a dropped ceiling and insulate the area between this and the original ceiling. But, with a pitched roof, you can add foam insulation into the existing roof.

Sometimes garages don’t have existing ceilings, so make sure to add some plasterboard if you need a ceiling in the garage.

How to Insulate a Garage Door

What you do with the garage door will depend on what you want to do with the space. If you plan on converting your garage into a liveable space – the best option is to remove the garage door and infill the space with a new wall, adding an internal door if you don’t have one already.

However, if you still plan to use the garage for vehicle access or other reasons and you don’t need to remove the door then there are a couple of ways you can insulate it.

Black-and-white image of a closed garage door

It is fairly easy to do and all it involves is doing some DIY weather-proofing. You can purchase adhesive padding and draught-proofing strips that stick to the door and help retain heat - such as these ones from Weather Defender.




4 Types of Garage Doors You Need To Know About (Before You Buy)

Read article


There you have it. There are so many ways to insulate your garage and it is fairly simple to do so. It all depends on what you want to do with the space, your budget, and the time you have to spend on DIY and planning. 

If you are planning to convert your garage into a liveable space, there are certain rules and regulations you will have to follow, and therefore you’ll likely spend more time and money insulating your garage.

But, if you just want to insulate the space for added heat yet still use it for storage or vehicle access then you may not have to spend as much time or money. 

Whether you’re converting your garage or not, we hope you feel like you know how to insulate your garage and the different ways to do so.

Want to make money by renting out your garage? Find out how much you could be making on Stashbee.


Rent out my garage


Join thousands of Stashbee Hosts, start earning now

Start earning



30th Nov 2022