Metal Building Insulation

Options and Prices

Did you know that every steel building other than carports require an insulation package? If you’re a first time buyer, this fact may not have crossed your mind, but metal building insulation is essential if you want your structure to last for generations. Lets explore the importance of steel building insulation, price ranges, options, and other helpful information to assist you in planning a successful project.

Why Do I Need Steel Building Insulation?

Insulation helps maintain a comfortable interior temperature by keeping warm air in your building during the winter and conversely by keeping warm air out during the summer months. More importantly, steel building insulation creates a barrier throughout the roof and walls of your building, which prevents condensation.

Where Should I Insulate?

At the very least you should choose to install some type of insulation in the roof of your building and if you live in an area with varying weather patterns we strongly recommend insulating the walls as well. For example, if you live in an area where snow will pile up against the sidewalls of your building, insulating the walls is extremely important.

Doing so will break the steel-to-steel contact that will in turn prevent condensation and resulting rust. Steel building insulation is typically installed by sandwiching the insulation between the sheeting and building skeleton as shown in the featured video.

Steel Building InsulationHow Much Insulation Do I Need?

The location and intended use of the building will determine the amount and thickness of insulation required. The great majority of insulation options will be between 2″ and 12″ thick. At General Steel we typically recommend 2″ insulation for storage buildings with no HVAC for any location, and 12″ for commercial and residential buildings.

Square Footage Formula:

Width x Length x Roof Pitch Value

This simple formula below will tell you how much insulation you need in the roof and walls separately.

Roof Pitch Values:

1:12 = 1.05
2:12 = 1.10
3:12 = 1.15
4:12 = 1.20
5:12 = 1.25
6:12 = 1.30

How Condensation is Created

Condensation is created when warm air from inside your steel building comes into contact with a cold surface such as your roof or wall panels. This mixture between the warm air and cold exterior surface causes the water vapors in the warm air to condense allowing moisture to congregate.

Why Water is a Threat to Your Building

Rust is caused by condensation and is one of the biggest threats to your steel building long-term. More specifically, your building’s structural integrity can be severely compromised if rust is allowed to collect around your building’s connections, bolts and screws. Not to mention mold and mildew is almost a guarantee in an enclosed moist environment. The good news is this potential problem is easy to prevent by selecting one of the metal building insulation options outlined below. Each has a corresponding R-Value which is a measure of the insulation’s ability to counteract condensation (higher is better).

Metal Building Insulation Options and Prices

There are three basic types of insulation options: rolled, spray foam, and insulated panels. As we’ve discussed, insulation is not something you want to cut corners on and making sure it’s done right is essential to the long term durability of your building. Depending on the size of your building and what you’re planning on using the space for, you may want to purchase your insulation through your Project Coordinator at General Steel to ensure it’s done right. If you’re more of the do-it-yourself type, you can explore purchasing your insulation package locally. All things considered, metal building insulation prices will vary, but here’s a quick guide we put together by surveying multiple local insulation sources to give you an idea how much it will cost.


R Values: R-11 for 3.5” to R-38 for 12”

Metal Building Insulation Options: BattBetter known as fiberglass insulation or batting, this type can be found at your local hardware store and is perfect for do-it-yourself projects.

While effective, this type of insulation does not provide the highest R-Value available and is susceptible to deterioration.

Local Price:

Depending on thickness, rolled insulation can cost $0.12 to $0.60 per square foot, roll insulation is by far your cheapest option and may be your best bet if you’re looking to build a new metal garage or workshop. For example, insulating a 30’ x 40’ two-car garage space would cost you between $150-$600 before installation.

Spray Foam

R Values Open Cell: 3.6 per inch sprayed | R Values Closed Cell: 6.5 per inch sprayed

Steel Building Insulation Options: Spray FoamThere are two types of spray foam insulation: open cell and closed cell. Open cell is cheaper but requires a thicker layer, so it may be your best choice if your framing is thick enough. Closed cell on the other hand is by far the more effective choice. Besides providing a higher R-Value per inch, closed cell is glue like and can increase your building’s structural integrity. Spray foam is typically installed by a professional using a small spray gun. Spray foam is great for unfinished areas like steel garage buildings and to insulate around obstacles.

Local Price:

Open-Cell Polyurethane Spray Foam: $1 to $1.20 per square foot to achieve a value of R-13. By comparison, our 30’ x 40’ example above would cost around $1,200-$1,500.

Closed-Cell Polyurethane Spray Foam: $1.75 to $3 per square foot to achieve a value of R-13. Therefore, the 30’ x 40’ example garage would cost around $2,100-$3,600.

Metal Building Insulation PricesInsulated Panels

While insulated panels are the most expensive option, there is truly no substitute for this great product. These panels cut a step out of the erection process, and even during the hottest summer day the inside of your wall panels will be cool to the touch.

Local Price:

Polystyrene Insulated Panel: $6-15.00 for a 1-inch thick, 4×8 ft. sheet.

Polyisocyanurate Insulated Panel: $22 for a 1-inch-thick, 4×8 ft. sheet.

An Insulation Option You May Not Have Considered

Although metal carports do not require insulation many people who choose to construct this type of steel building do so because they plan to fill in the gaps with concrete blocks. Including its R-Value of 2-2.5 per inch, there are various reasons why you may choose to use concrete blocks rather than traditional steel wall panels, but the most common reason is increased security.

Have Questions? We Have Answers

Our team at General Steel has supplied buildings designed for virtually every use imaginable. If you have questions about metal building insulation or any of the other factors that will make your project a success, contact us for a free project consultation and quote.

Expert Advice: Steer clear of any steel building company who suggests that you don’t need insulation, but perhaps even more treacherous is a company who provides inferior insulation. Be sure to ask for photos of the type of insulation you will receive because there are companies providing what amounts to a low quality bubble wrap backed by aluminum foil.

Resource: houselogic.com/home-advice/insulation/insulation-types

Metal Building Insulation Prices
Article Name
Metal Building Insulation Prices
Accounting for an insulation package in your project budget is a must when it comes to metal buildings. There are many insulation options to choose from to accommodate your budget as well as the temperature conditions local to you.
Publisher Name
General Steel
Publisher Logo

How to Price Your Building