How to Insulate your Metal Building - 6 Best Ways

What is the Best Type of Insulation for Metal Buildings - Weatherproof Solutions

Are you looking for the best ways to insulate your metal shed or garage for a moisture-free storage space? You have come to the right place!

Metal structures are usually durable and easy to maintain if you know the right way to go about it.


 ALSO READ: 9 Best Duramax Sheds For Your Yard

However, metal is a good conductor of heat and insulators are required to manage the temperature in the garage. Without insulation, your metal garage will amplify the external conditions and end up affecting the interior.

During spring and fall, the warm days and cool nights will lead to condensation that leads to the formation of water droplets on the interior of the shed.

Let's take a look at 6 different types of insulation and insulation material that you can incorporate to your metal structure. 

6 Ways to Insulate Your Metal Garage

  1. Fiberglass Batts
  2. Rigid Foam Board
  3. Spray Foam
  4. Mineral 
  5. Brown-in Cellulose
  6. Vapor Retarder

Before Insulating Your Metal Building:

You will need to plan adequately for the best results. Here is a list of things you should check before insulating your metal garage.

  • Take the measurements of the ceiling, wall, and floor of your metal garage.
  • Remove the internal wall sheathing if you need to.
  • Coat the wall in 2-inch layers using closed-cell spray foam.
  • Let the spray foam dry between the layers.
  • Repeat the process for the ceiling and wait for it to dry.
  • Lift to install strong foam panels under the floor.
  • Alternatively, remove the floor to install strong foam panels between joists.
  • Re-install the flooring and interior sheathing if you want to.

3 Critical Reasons For Insulating Your Metal Garage

First, you need to understand that metal buildings are good thermal conductors. This makes it difficult to keep them moisture-free, which could damage the structure's metal panels and steel frames.

Insulating your garage will make it withstand all weather conditions and last longer.


 Here are some of the reasons why you should insulate your metal garage:

Condensation in Your Metal Building

Your garage will get heated up all day long. At night, the heat will want to escape when it gets cold.

Metal being a good thermal conductor, allows the internal heat to leave the garage and when this happens, water droplets form on the interior side of the garage due to condensation.

Condensation causes the interior floor of the garage to have water marks all around the base, and eventually rust. The droplets could form on the ceiling and begin dripping on the floor.

If your floor is wooden, this could cause rot and damage to the structural integrity of your garage.

Control Interior Temperature

Insulation will reduce the amount of condensation on your walls and ceilings. Regulating the heat transfer from the exterior walls to the interior will help maintain a comfortable temperature in the summertime.

It will also lead to reduced heat loss in the evening and on cold nights. Roof vents in the gables of your shed are effective in removing moisture from the interior of your metal garage.

Insulating your Metal Shed for Acoustic Control

If you plan on using your metal garage as a workshop or studio, it will lead to increased reverberations. Fiberglass batts, rigid foam, or spray foam insulations will dampen loud sounds coming from your garage.

Best Practices for Insulating a Metal Structure

1. Using Fiberglass for Metal Building Insulation

Fiberglass batts are very popular insulators for metal sheds. Bigger, prefabricated metal sheds sometimes come with fiberglass batt systems pre-installed.

The main advantage of fiberglass is its R-value. It has a good R-value of about R-13 for 4 inches and is also very affordable.

Moisture is the main problem threatening your metal garage. Fiberglass performance is affected by moisture. Faced fiberglass batts come in convenient rolls.

The faced part is made of plastic, vinyl, or paper composite and is ideal for sheds. Facing waterproofs the fiberglass and protects its R-value.

Fiberglass batts completely covered by plastic, vinyl, or other water repellents are usually more expensive but offer good value for money. It is also very durable, easy to install, and works well on ceilings and walls.


2. Install Rigid Foam Board

This is another good alternative for weatherproofing your metal garage. They are rigid as the name suggests and sheds with curved surfaces will struggle to install rigid foam boards.

Most metal sheds possess studs that are not the regular 16” or 24” wide. You may need to cut your foam up severally to fit or double pieces of foam to fit bigger gaps. You will end up fitting foam into oddly-sized stud openings regardless.

You can always tape seams and install a vapor barrier, but the gaps between the foam panels will always allow heat and moisture to move in and out.

Installing rigid foam boards is a more affordable alternative to using spray foam for garages without studs. Rigid foam boards are best used on the floor of a metal shed. If the floor is made of metal as well, foam can also be used under the entire shed.

3. Spray Foam Insulation - The Vapor Barrier

Spray foam gives you the advantage of being a vapor barrier as well as having a very high R-value per inch rating making it very convenient.

Closed-cell polyurethane spray foam properly seals the inside of your shed from thermal conduction and moisture from the outside.

This foam waterproofs your metal garage in the winter. It is very important to insulate your metal garage in the winter to remove excess moisture and prevent the spray foam from condensation on the interior ceiling and walls.

Closed-cell polyurethane spray foam kits are available at most stores. They are a bit expensive but they are easy to install by yourself.

Just spray onto the walls of the shed in 1-inch layers. Repeat for the ceiling as well. Spray foam is hard to remove once applied.


4. Using Mineral Wool to Insulate Metal Buildings

Mineral wool works almost like fiberglass batts. They come in 4” and 6” wall stud applications. Mineral fiber has good moisture-resistance properties. It shouldn’t come in contact with water as it will shrink and lose its R-value.

Mineral fiber is composed of various components, such as crushed stone, making it much easier to handle compared to fiberglass. It is fireproof as it is made from molten rock.

Mineral wool insulation isn’t available in foil-faced versions, which are an alternative for metal garages. They are more rigid compared to fiberglass-faced and encapsulated insulators, making them harder to install on curved roofs.

If your metal shed is studless, applying this insulation will be difficult.

5. Install Blown-in Cellulose to your Metal Garage

It is a mixture of old newsprint, sawdust, or other products of waste paper giving it an equal R-value to mineral fiber. It is not fireproof or mold-proof as it is a paper product. When installing this insulation in your metal garage, you must fix a barrier for the insulation to fall into. 

Your garage must have sheathing on the ceiling or a vapor blockade with an opening that will allow you to fill it with cellulose.

It also has fire retardant properties to reduce its combustibility. This insulation shouldn’t come into contact with water to reduce its chances of growing mold.

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6. Add Vapor Retarders to the Metal Frames

Vapor retarders are a good component of fiberglass insulation. It helps further reduce condensation by regulating the amount of vapor entering your building via the walls or roof. This is ideal for metal garages that still face condensation problems after installing an insulation system. The many issues resulting from condensation have been discussed in this article.

TAKEAWAY - Best Insulation Methods

While fiberglass is the best way of insulating your metal garage, you may also consider spray foam insulation. Alternative reasons are not recommended for various reasons such as reduced R-value, maintenance costs, or fire hazards.

Some insulators may contain harmful chemicals that may be harmful. Fiberglass is highly recommended because it is durable, attractive, and effective. These are some of the ways you can use to insulate and weatherproof your metal garage and keep your storage space moisture-free.