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10 Tips For Insulating Your Outdoor Shed

Insulating a Shed

There are a few ways to insulate a shed and depending on what you’re going to be using your shed for will determine how you’ll need to insulate your shed. With some good planning during your shed build adding insulation won’t be a problem.

In this article I’m going to look at 10 tips that will help you with insulating your shed and which materials you need to use. Most folks insulate a shed so it’s more comfortable to be in especially if there using it as a workshop or even and office space.

10 Tips For Insulating a Shed

1] Considerations… If you’re trying to keep your shed cooler in the summer and warmer in the winter than adding insulation will greatly help. Let’s look at the 2 most important considerations.

– Your Location… What type of climate conditions do you live in? Living in a cold climate will require more insulation in the walls and the ceiling; you’ll also want to add some insulation into the floor before you apply the sheeting. Also use double sealed windows and an insulated exterior door.

Heating and Cooling… If you’re going to be insulating a shed then you’re going to need to know how you’re going to keep it cool and heat it in the winter. Do this before you insulate your shed and close in the walls and ceiling.

2] The Insulations “R” Factor… You’ll hear this term used when you’re looking at buying insulation, whether it’s batt insulation or another type of insulation. The “R” factor simple means an insulation’s ability to prevent heat loss or keep heat out. The higher the “R” factor the better it will resist heat transfer.

The building code will determine the required amount for each area, if you’re not sure the local building authority or building inspector can tell you what you would require. In my area in Northern British Columbia the minimum required is R-22 for walls and R-44 for ceilings. This is for a home, a shed has no requirements here, but it may in your area.

Download Shed Plan

3] Types of Insulation… There are several different types of insulation available, but the most common is batt insulation. It’s the easiest to install and come in different thickness and can be used in floors, walls and ceilings to provide the “R” factor you need.

– Batt insulation… It’s made from fiberglass or other natural fibers and has specialty uses for increasing fire rating and sound proofing applications.

– Blow-in… Is made from fiberglass, cellulose and is typically blown into the attic space to the required thickness. It can also be blown in between stud spaces in older homes from the outside to improve the homes “R” rating.

– Rigid… This is usually constructed from a type of polystyrene and is commonly sold in 2 foot by 8 foot pieces and can be in different thicknesses. Is used on the outside of a home’s walls to increase the “R” factor.

– Reflective Type… Is constructed with a reflective side and you made have seen it as a shiny bubble wrap. It is typically used on the outside of walls under the finished material.

4] Sealing the Shed… Another way to insulate a shed is to make sure that its air tight, you need to seal up any places where air is coming in from. Most sheds that are used for storage of lawn equipment and gas cans won’t be very air tight on purpose; this allows any fumes to escape.

Now that you’re going to insulate your shed so you can use it as an office or workshop you’re going to need to insulate it so it’s usable all year round. You’ll also need to look at proper ventilation and vapor barriers to prevent moisture from getting into your shed during the insulating and finishing process.

5] Controlling Moisture… Controlling moisture will save you from having to do expensive repairs to the shed. Insulating your shed and controlling the moisture will better the quality of air and make it much easier to heat and cool the shed. Another thing to consider is moisture promotes the growth of mold which is unhealthy.

Cooler or warmer air entering the shed is usually the main cause of moisture problems as well a poorly ventilated shed will cause moisture problems too. Left unchecked the moisture can lead to the insulation getting wet and cause the untreated wood to rot. Normally the sheds floor would be constructed out of treated wood, but the walls and rest of the framing and sheeting is regular wood.

Inspect your roof overhangs and eaves to make sure they are finished correctly and sealed to prevent any moisture from penetrating the roof and walls causing excess moisture to the interior wall and roof framing. Make sure you use a good quality eave’s protection under the shingles to prevent water backup and leaks inside the sheds roof.

Shed Plans

Install the eaves protection so it goes up the roof 2 times the overhang width or just use 30 pound breathable felt paper under the shingles for the whole roof. Also be sure that your shed is built on higher ground to allow for water to drain away from the base. I have 2 articles that you can get more information from, the first is “How Do I keep Moisture Out of My Storage Shed?” you can read it here and the second is “What’s the Best Location For an Outdoor Storage Shed?” you can read the article here.

6] Vapour Barrier… When you insulate your shed you need to install a vapour barrier over the insulation to prevent moisture from getting into the interior finish of your shed. The most common form of vapour barrier is 6mm plastic and its attached on the inside of the wall framing overtop of the insulation.

You’ll need to completely cover the ceiling and walls with vapour barrier for it to be effective. Use tuck tape on all the joints and around electrical outlets to stop moisture from coming in. I’m going to recommend “TRM Manufacturing 6mm Plastic Sheeting Vapour Barrier” as a good quality vapour barrier for your shed.

It comes in a large 10 foot by 100 foot roll witch will be enough to do the inside of most sheds. It has 40 answered questions and 63 user ratings. You can read the reviews and get more information here on Amazon.

I’m going to recommend “3M Construction Seaming Tape” for sealing all the seams in the vapor barrier. You can get some here on Amazon.

7] Preparing For Insulating Your Shed… There are a few things you’re going to have to do before you go ahead and insulate your shed.

– Any Electrical Work to Do?… If you’re planning on insulating your shed it’s likely you’re going to need some electrical outlets and lights. Be sure to consult an electrician to have the shed wired for the electrical needs you’ll want.

– Any Plumbing?… Most sheds won’t have any plumbing, but depending on what your plan is you may want some running water and maybe even a hot water tank.

– Cable or Phone Line… You may want to have a phone line installed in the shed if you’re going to be using it for an office.

Once you have done any of the electrical, other cables and any plumbing now it’s time to go ahead and insulate the shed and install the vapor barrier and interior finish.

8] How to Insulate a Shed Floor… If you have an existing shed then insulating the floor can be difficult as most sheds are sitting very close to the ground. Your two options for insulating an existing shed floor are:

– Number 1]… Jack the shed up so you can crawl under it and install insulation into the floor joist spacing, than apply some typar building wrap to the underside to prevent the insulation from falling out.

– Number 2]… Cut out the floor from the inside and add insulation into the joist spacing and then install a 6mm vapor barrier on the top and then re-install the sheds flooring.

If your building a new shed then insulating a shed floor will be much easier, most sheds use 2×6 floor joists and you can use R-22 batt insulation either for 16 or 24 inch centers. I would recommend 16 inches joist spacing to help stop the insulation batts from falling thru the space.

Ryans Shed Plans

I use cardboard and cut in wider and attach it to the joists on the bottom sides to make a support for the insulation. Once you have added the insulation apply a layer of 6mm vapor barrier and apply the floor sheeting and keep tarped over ifs it raining.

9] How to Insulate Shed Walls… Using R-12 insulation for 2×4 walls and R-22 insulation for 2×6 walls work the best for insulating shed walls. Depending on your stud spacing you will use batt size or 15” for 2×4 walls and batt size 23” for 2×6 walls.

Great Stuff Smart Dispenser Foam InsulationBegin by installing the full batt into the top stud wall space and then cut the bottom piece about 3/4/ of an inch longer. Next, install the bottom batt and make sure you don’t over compress the batts. You’ll need to remove small pieces of insulation to fit around plug, light and switch outlet boxes.

Where’s there wiring running through the wall just measure to the wire and using a utility knife cut about halfway into the batt from the back side and then carefully position the batt so the wire goes into the groove you just cut.

You’ll also want to cut thin strips of insulation to fill in spaces around windows and doors. If the spaces are really small you can use some spray foam insulation and cut off the excess. I recommend “Great Stuff Smart Dispenser Foam Insulation” because it works really well and it’s pretty cheap to buy. You can check it out yourself on Amazon here.

Once you’ve finished insulating add the 6 mm vapor barrier and use the “3M Construction Seaming Tape on all the joints and you can use it to seal around the electrical outlet boxes to ensure a good seal. If you want to add a bead of acoustic sealer caulking in the corners and top and bottom edges before installing vapor barrier.

Note… Acoustic caulking is REALLY messy to work with and not easy to remove.

10] How to Insulate a Shed Ceiling… The way to insulate a shed ceiling will depend on the type of roof you have. If you’re planning on building a shed and you’re going to insulate it, then the design of your roof is important. The 2 types of shed roofs that work well to insulate are the “gable roof” and the “lean to”. Let’s look at both:

– Gable Roof… This is the most common type of roof for homes and for sheds and works well for area’s that are subject to cold winters. It basically consists of 2 separate sections that go from the top of the wall to the center creating two roofs that meet in the middle.

This design creates an attic space that can be used for storage and allows for thicker amounts of insulation to be used. It can also have varying pitches to create a lower roof or a higher roof. The gable roof also allows for easy ventilation which is important for controlling air movement in the attic space helping with cooling and keeping the shed warmer.

Attic Insulation StopsMake sure you have gable vents or roof vents installed, before installing the insulation make sure you add insulation stops [baffles] every second rafter space. Insulation stops allow for air to enter the roof space thru the soffit and exit thru the gable or roof vents to prevent condensation from forming and it also lets hot or cold air enter and leave the attic space which helps control temperature.

Once you have installed the insulation stops [baffles] you can proceed to insulate the ceiling with 2 layers of R-22 insulation, one row between the rafters and another going the length giving you R-44 insulation in the attic space. Once you have completed the insulation install the vapor barrier and seal all the joints with construction ceiling tape.

– Lean To Roof… This is also a very common roof for sheds and very easy to build, however if you’re going to be insulating a lean to roof you’ll need to provide at least two inches of space above the insulation for air to flow from the soffit up thru the roof and out air vents at the top.

You’re going to want to use 2×6 rafters, strapped on the bottom with a one inch filler to lower the R-22 insulation so it’s about ¾ to 1 inch below the top of the rafters. Or better yet you can use 2×8 rafters which will provide 2 inches of space above the insulation. There are several ways to do this:

– First… You’ll need to drill holes, 1 inch holes every 16 inches into the top 1 ½ inches into each 2×8 rafter for air flow.

– Second… Strap the top of the rafters with 2x4s either directly on top of the rafters or across the entire roof. This will depend on what type of roofing you’re going to be using. Strap if directly and sheet the roof with ½ inch plywood if you’re going to be using shingles.

If your using metal roofing cross strap the rafters every 16 inches with 2x4s and then add the 30 pound felt paper from top to bottom. Now you can install the metal roofing, you’ll still need to add some roof venting at the top of the roof.

How to Insulate Doors and Windows

These will big the main places you’ll need to insulate and seal around in addition to insulating the floor, walls and ceiling. Depending on how much of a gap you have around the window and door frames will dictate how you will seal these openings.

– Tiny cracks can be filled with a good quality waterproof type of caulking.

– Larger gaps can be blocked with some spray foam insulation.

– Bigger spaces should be filled with pieces of batt insulation.


These tips for insulating your outdoor shed will give you a comfortable place to use all year round, remember it vital to make sure you use vapor barriers and proper ventilation for your own protection from mold and moisture damage.

If you’re not sure about something ask a question, or go talk to your local building inspector and they can give you the information you need to insulate your shed in your area. You can also go talk to someone in your local building center or building supply store, they can also recommend local contractors if you need help. Thanks for reading! Give the article a share if you have found it helpful.