Cheap and Easy Insulation Ideas for Sheds

Insulating your shed is a good idea to use frequently.

If you plan to use it as an outdoor office, gym, storage shed, or crafting room, shed insulation is the best thing.

Insulation will keep it comfortable and keep it from getting too hot or cold.

You can insulate wooden and plastic sheds more so in a metal shed since metal sheds or metal buildings are good conductors of heat.

 Metal shed interior temperature can quickly become hot or cold.

In this article, you will know why insulation is important and how it can help extend the lifespan of your shed.

You will also learn to choose the best insulation materials for your shed needs.

Quick Comparison of Different Insulation Materials for Your Shed

FiberglassMineral FibersRigid Foam BoardsSpray FoamLoose-Fill InsulationsPlywood Boards with Polystyrene
R-Value (Heat Transfer Prevention) per Inch3. 1-3.43.1-3.44-

More costly if vapor barriers are present
CheapCheap Alternative to Spray FoamExpensiveExpensiveExpensive
Ease of InstallationEasyEasy
(Not suitable for curved spaces)
(Not suitable for curved spaces)
Takes a long time to applyHard to removeDifficult to install; needs pneumatic equipmentRelatively not easy
Moisture Prevention/ResistanceRelatively low but becomes more resistant if vapor barriers are presentMediumHighHighHighHigh
Sound ProofingYesYesYesYesYesYes
Fire ResistantNoYesNoFire- retardantDepends on material; some needs added fire- resistant chemicalNo, needs fire- retardant chemical
Best Suited forWalls and RoofWalls and RoofFloorsWalls, Roof, Door, and WindowsWalls, Roof, and FloorWalls, Roof, and Floor

Importance and Advantages of Having Shed Insulation:

1. Garden buildings, such as outdoor sheds, will benefit from insulation since they are more exposed to weather elements.

2. Insulation helps in avoiding extreme temperatures by regulating the shed’s internal temperature.

3. It helps in keeping off moisture and condensation inside the shed or small building.

3. Insulation helps prevent mold growth.

4. It helps in sound-proofing your shed, which is important if you use your shed as a workshop area.

Heat Transfer Prevention Capacity of Insulation Materials

Air transfers from warm to cold.

  • During the warm season, insulation keeps warm air from entering a shed with colder temperatures.
  •  In the winter season, it will prevent the warm air of the shed from going out to the colder area outside.

In short, insulation prevents heat loss if it’s cold outside; and cools it down when it’s hot outside.

Its R-value measures the effectiveness of any insulation material. R-value is the measure of how a material is resistant to heat flow.

Different insulation materials have different capacities to block heat, which contributes to its total R-value.

 The thickness of insulation material, its placement,  and how well it is installed will also contribute to a higher R-value.

That is why it is important not just to know the inherent heat blocking capacity of material;   but where,  and how to use it.

Different Insulation Materials Suited for Sheds

1. Fiberglass Batts and Blanket

Insulation of this kind are among the most common. You can buy batts and blankets in pre-cut strips and continuous rolls, respectively.

They are readily available in home improvement stores in conventional width to match the wall-stud and ceiling-rafter spacings for easy installation.

They usually have a vapor barrier (reflective foil/vapor-retardant usually placed facing the warm-in-winter side).  

Some do not have this barrier used in reinforcing existing insulation. It has a high R-value but without vapor barriers;  the R-value becomes lower and susceptible to moisture build-up.


  • Cheap
  • Easy to Install
  • Good R-value
  • Readily Available
  • Good Moisture Resistance (for foil-faced)
  • Suitable for wall insulation and roof insulation


  • Not fire-resistant
  • Fiberglass can cut through your hands if mishandled;  can cause itchy hands and neck
  • R-value lowers if in contact with moisture

2. Rock Wool Fibers or Mineral Fibers

Some batts and blankets have rock wool or mineral fibers as insulators.

They are more rigid than fiberglass so that it makes it a little difficult to install,  but they are safer to use than fiberglass.

They have good insulation and sound-proofing capacity. They are also fire and rodent-resistant.

They have a good R-value,  but lose it when in direct contact with moisture. The best option is  to use mineral fibers with vapor barriers to maintain its R-value.


  • Cheap
  • Easy to Install
  • Good R-value
  • Fire-resistant
  • Rodent -resistant
  • Suited for shed walls and floor


  • More rigid;  making it difficult to install in bent places
  • R-value and moisture resistance lowers if in contact with moisture

3. Rigid Foam Boards

Rigid foam boards are also good for insulation.

They do not require studs to be installed. You can simply use any adhesive to install them. They also have high moisture resistance.

 However, some sheds do not have the conducive build for foam boards,  and you might cut off excess foam to fit your shed.

 It is also difficult to install in curved spaces;  that is why it is suitable for shed floor insulation.


  • A relatively cheap alternative to spray foam
  • Good for sheds without studs
  • Excellent choice for floor insulation
  • High moisture resistance
  • Good R-value


  • Difficult to install in curved spaces
  • Needs additional vapor barrier and ventilation
  • Needed to be cut;  to fit in-wall and ceiling cavities

4. Spray Foam Insulation

Spray foams also act as vapor barriers and offer a high R-value. It effectively seals the inside of your shed.

Since it is very effective in keeping moisture out  during the winter months;  in which it will be heated inside, it is advisable to install ventilation to avoid condensation.


  • Great R-value
  • Acts as vapor barrier
  • Good moisture resistance
  • Fire-resistant
  • Best suited for door insulation and window insulation


  • Expensive
  • Longer application process
  • Hard to remove
  • Needs to install ventilation

5. Loose-Fill Insulation

Loose-fill insulations are blown or filled materials, usually made from glass, rock, cellulose, vermiculite, etc.

They are poured and filled in the spaces requiring pneumatic equipment.


  • Great R-value
  • Acts as vapor barrier
  • Good moisture resistance
  • Great for blocking airflow


  • Expensive
  • Not easy to install
  • Some loose-fill materials are NOT fire-resistant, not unless sprayed with chemicals that are fire-resistant or retardant

6. Plywood Boards with Polystyrene

Polystyrene is a transparent thermoplastic used in making the foam board. It is then reinforced with plywood boards with foil back, to serve as a vapor barrier.

The added plywood board further slows down  the heat transfer.


  • Great R-value
  • Acts as vapor barrier
  • Good moisture resistance


  • Relatively expensive
  • Not as easy to install compared to others
  • Not fire-resistant, needs to add retardant chemicals

7 Things to Consider Before Insulation

Before undertaking a shed insulation project, here are the important things that you need to think about:

1. Consider your electrical and plumbing plans and prepare for ventilation needs.

2. Understand your requirements. Measure your shed properly.

3. Choose the best option for insulation materials suited to your need and shed type.

4. If you decide to proceed, clear your shed and the surrounding area.

5. Check for airtightness prior to full insulation.

6. Fill the holes first with spray foam or any insulation materials to seal your shed.

7. ALWAYS use protective gear.

Quick Guide for Easy-to-Install Shed Insulation

A. Spray Foam

1. After removing all items inside the shed, tape the vents, windows, doors, outlets, and switches with plastic.

2. Wash the walls, ceilings, and floor, and thoroughly dry them.

3. Spray the foam onto the ceiling cavities, then the wall panels.

4. If stud cavities are present, fill the frames first,  then the middle afterward.

5. For doors and windows, you can also spray foam to the frames  and simply cut off the excess once it dries up.

6. After insulating the interior, lift ‌your shed,  and apply the spray foam underneath the floor,  between the joist cavities.

 7. Make sure that it is clean before application.

8. If you cannot lift your shed, dismantle the flooring and apply the spray foam.

9. You may use a plank board for easy lifting of your shed.

PRO TIP: Do not spray over 2-in thick foam to reduce fire risk.

B.  Rigid Foam Boards

1. Remove items from the shed and clean the shed.

2. Measure your walls, ceilings, and floor.

3. Cut the foam boards to snugly fit the cavities.

4. If your shed doesn’t have studs, simply cut the foam at the height of your shed.

5. After insulating the wall, start installing the ceiling.

6. Cut the foam to fit the ceiling rafters.

7. If there are no rafters, use adhesive.

8. Access your floor cavities and cut the foam to fit the joist cavities.

9.  If there are no joists, simply lay the foam covering the entire floor.

PRO TIP: Layer your foam to increase R-value.

  •  Make sure the foam fits right but is not too tight,  to avoid distortion.

How to Prolong the Life of Your Shed

  • Best way to control moisture is to control temperature. Insulated sheds will not keep too much heat and encourage mold growth.
  • Install gutters and downspouts to control water and moisture.
  • Stain your shed to weatherproof it.
  • Immediately repair damaged parts.


Should I have an air gap between the insulation material and the application surface?

Yes. If you are using reflective foil or radiant barrier as insulation, an air gap is important for the insulation to be effective.

When there are no air gaps, your insulation materials will directly conduct the heat.

Is there another way to insulate the floor if it’s hard to dismantle it?

Yes. You can simply lay a breathable membrane on the floor and put a carpet on top of it.

Does bubble wrap work for insulating sheds?

Yes, but ‌use the foil-backed bubble wrap insulation. You can simply tack it into your wall.

What is PIR Foam Insulation Board?

Construction industry experts consider polyisocyanurate to be one of the best insulation materials available.

PIR board is an improvement of previously used PUR board  (polyurethane), typically produced as a foam, and used as rigid thermal insulation.

 The insulation core and facings resist attack by mold and microbial growth.


Insulating your new shed is an important step to prolong the lifespan of your shed. It will prevent the shed from rotting and causing damage.

D. Hahn

DIY guru, dad, husband, blogger. When I'm not creating life hacks I'm teaching my kids how to fix stuff after their dad breaks it.

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