Do you spend a lot of time in your shed and want to make it more comfortable to work in?
Are you a hobbyist, craftsman or artist and store perishables such as paper, stock or materials in your shed and want to make sure they’re kept safe and dry?
Do you want to know how to avoid damp, moisture and mould in your shed?
If so, you’re probably looking for expert advice on how to insulate your shed.
We’ll cover all of the following in this article:
- The benefits of insulating your shed
- What materials to use to insulate your shed – bubble wrap vs fibreglass wool vs foil backed compression insulation
- Lining the inside of your shed – Recommended materials and pricing
- How much does it cost to insulate your shed?
- How long does it take to insulate your shed?
- How to insulate your shed walls, roof and floor
We have been insulating our sheds for over 25 years – that’s a lot of cozy sheds. Its’s safe to say that we know what it takes to do the job right.
There’s a fair bit of information out there on how to insulate a shed but not much reasoning as to what is the best way and why.
We want to make sure that you have all the information you need to make your shed a comfortable, safe and warm place to be.
What materials do you need to insulate your shed?
Firstly, you need to determine your framing size to figure out how much room you have to fit in your Insulation.
Gillies and Mackay framing is 75mm allowing 50mm of insulation and a 25mm air gap.
The air gap is important because it allows the exterior wall to breathe and stops moisture from traveling through to the internal of the building – more on this later.
If your framing is less than 75mm you may need to use a thinner board of insulation to accommodate the air gap.
2. Insulation: Bubble wrap vs fiberglass wool vs foil backed insulation
Bubble wrap for insulating your shed?
Using bubble wrap for insulation is dangerous if you plan on putting electrics in your Shed, which is often the case for why people might be thinking of lining and insulating their shed in the first place.
So polystyrene or bubble wrap are a major no no! They can combust with electrics and set the whole shed on fire. Not cool.
Fibreglass wool for insulating your shed?
Fibreglass wool as insulation is ideal for bathroom areas and for soundproofing, but can be a real nightmare to handle and fit.
Do not follow the advice in this article – we do not recommend this solution.
Foil backed insulation for insulating your shed
Realistically this leaves you with one good option: Foil backed compressed insulation is the best and easiest to work with, and we highly recommend this option for your shed.
Ecotherm foil backed compressed insulation has the best U-value for efficiency and is completely safe with electrics.
There are three main brands of foil back compressed insulation to look out for: Kingspan, Celotex, Ecotherm – they all do the job and are readily available from warehouses such as Wickes.
Here are a few foil backed insulation recommendations to help you with your search:
- Ecotherm: Eco-versal 50mm 2.4m x 1.2m
- 50mm Celotex GA3050 / Recticel Insulation Board 2400x1200mm
- 50mm Thermawall TW55 PIR Insulation Board Kingspan
How to insulate your shed walls, roof and floor
Insulating your shed wall and roof
Step 1: Protect the wood with anti-fungal treatment
Your shed wall won’t be accessible once you’ve insulated so you need to consider extra preservation. You can either use the same wood protection you have used on the outside, or you can buy an anti-fungal/pesticide wash to treat the internal (some companies do this already, so check with your manufacturer).
- Recommended product: Lignum Fungicide and Insecticide Pro D156 1L (Be sure to check how much you will need per meter coverage for your own building size)
Step 2: Create the cavities
Add a 25mm x 25mm strip of wood (preferably treated) down the side of each stud (frame).
This will create a cavity between the external wall and the insulation. Ideal for electrical wires and eradicates damp penetration.
Step 3: Cut the insulation sheets to size and slot them into place
Measure each wall section. If you’re fortunate your shed will be made to exact centres – e.g. 600mm.
Cut each section from your 2.4m x 1.2m sheet of foil backed insulation. You should get 2 sections from each sheet.
Slot the section into place (on top of the 25mm strip, creating a gap between wall and insulation as mentioned) and repeat on all 4 walls.
Complete the same process for the roof.
Insulating your shed floor
Insulating your floor isn’t going to be easy if your shed is already assembled – normally the insulation sits between the floor joists.
However, investing in a decent underlay and laminate (should your frame size allow) will give you adequate insulation.
If you’ve not assembled your shed yet, follow the same process as the walls for the underside of the floor (add skirting once assembled to keep it neat).
Now all your insulation is in place you can think about lining options.
Lining the inside of your shed
At Gillies and Mackay we opt for 16mm Redwood V’d Lining.
However this isn’t always as readily available to you and I’d suggest calming it down a bit as 16mm Redwood is a bit over the top.
Maybe opt for something like 9mm MDF Beaded Board available from accessible warehouses. It’s a profiled sheet that looks like cladding (see image above).
It’s also neat and easy to work with.
- Recommended product: Matchboard 9mm x 1222mm x 2440mm York Moisture Resistant MDF Panel Portrait – Long Joint
How long does it take to insulate your shed?
If you decide to insulate your shed yourself, it’s likely to be a weekend job depending on your DIY competency.
If you hire a manufacturer or supplier to do it for you it’ll be a half day or full day depending on the size of the job.
How much does it cost to insulate your shed?
DIY costs – Insulating your shed yourself
If you are going to to it yourself, using 50mm insulation, here’s some approximations based on £35 including VAT per sheet of foil backed insulation.
Small shed/summerhouse – 8’x 8′
To insulate the walls, floor and roof you will need approximately 10 sheets of 50mm foil backed insulation. Based on the prices above, this will cost approx. £350 including VAT.
Add 8 sheets of lining at approximately £40 = £320
Total price for 8′ x 8′ = £670 including VAT
Medium shed/summerhouse – 10′ x 10′
To insulate the walls, floor and roof you will need approximately 15 sheets of 50mm foil backed insulation. Based on the prices above, this will cost approx. £525 including VAT.
Add 12 sheets of lining at approximately £40 = £480
Total price for 10′ x 10′ = £1005
Large shed/summerhouse – 16′ x 12′
To insulate the walls, floor and roof you will need approximately 24 sheets of 50mm foil backed insulation. Based on the prices above, this will cost approx. £840 including VAT.
Add 19 sheets of lining at approximately £40 = £760
Total price for 16′ x 12′ = £1600
Note: You may find that the prices will be cheaper if you buy in bulk. These prices are not 100% accurate, but should give you a good indication of the prices to expect.
What about the costs of hiring a company to insulate your shed?
If you don’t want to insulate your shed yourself, you can expect to pay roughly double the costs for a manufacturer or supplier to do it for you.
Final words from Gillies and Mackay on insulating your shed…
Here at Gillies and Mackay we fully recommend insulating your shed/summerhouse. It’s completely worth it and allows you to have an amazing #shedlife all year round.
Insulating your shed is especially important if you are using it as a garden office or workshop, and it will help to protect everything on the inside from the cold, damp and moisture.
If you have any concerns or questions about insulating your shed, summerhouse or garage, please contact us and we’ll help as much as we can.
If you are interested insulating your shed, you’ll also find these articles helpful: