What is a Sandwich Panel?


A Sample Sandwich Wall Panel To Show Cross Section

In the most basic terms, a sandwich panel is a panel type composed of three (or sometimes more) materials that are adhered together to form one. Sandwich panels are used in a variety of applications in the construction industry from roof panels to floor panels to the very walls that make up a building itself. Sandwich panels can also be referred to as composite panels, meaning they are formed out of more than one type of material.

Sandwich panels are referred to as a sandwich because of the configuration of the panels. The panels have three basic components: the two outward-facing layers and a thick core; the two outside panels act as the "bread" of the sandwich and the core is the meat.

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Generally, the two outward-facing layers are applied to help increase the overall durability of the panel or in certain cases, additional layers can be added to a sandwich panel to enhance its other characteristics. Keeping with the sandwich analogy, sometimes some additional 'ingredients' (materials) can be needed in order to make the perfect sandwich panel for you.

With our sandwich wall panel system, these specific characteristics are usually most important: STC (Sound Transmission Class) rating, R-Value, and Fire Rating.

Each of these panel characteristics can be extremely important to a project, depending on the environment the sandwich panel system would be going into. For example, a wall panel system being delivered to a warehouse in Maine might require a different panel type than a chemical facility in Arizona.

Example of a Panel Built Sandwich Panel with Additional Steel Skin for Extra Durability

STC Rating

Let's begin with a panel's STC rating. Standing for Sound Transmission Class, STC refers to the panels ability to reduce the noise passing through it. This characteristic is most important in heavy manufacturing facilities or any facility where workers must endure loud noises for a prolonged period of time.

The most effective way of increasing the STC rating of a sandwich wall panel is to add additional substrates to help absorb the noise. For Panel Built, we have adopted a specialized designed fiberboard that can be added to any of our panel configurations to instantly increase its STC rating. These sound deadening panels are often utilized in the installation of modular breakrooms, offices, and conference rooms in facilities with a higher than average noise level.


Another vital characteristic of a sandwich wall panel is its R-Value. R-Value is a common construction and building term that refers to a materials insulating capacity or its ability to resist the flow of heat. Panel Built's standard wall panel has a thickness of 3" (although this can be altered for specific applications). In order to increase the R-Value of a panel, you will need to make the insulating portion of the panel (the core) as thick as possible or construct the panel of another core material.

Server Room
Some Special Purpose Rooms Can Use a Higher R-Value to Create Energy Savings

For example, take our popular Gypsum/Gypsum wall panel. Looking at its configuration, the G/G panel has two 1/2 inch gypsum boards on each side, leaving 2 inches of insulation for the polystyrene core. This configuration offers an R-Value of 11. However, we can change the insulation of the Gypsum/Gypsum panel to a Poly-ISO core and instantly boost the R-Value to 17, greatly increasing the heat resistance of the structure.

Sandwich panels with increased R-Values can be found in environments that are both hotter and colder than usual. If the wall panel does a good job of keeping outside heat outside then it will likewise do a good job of keeping inside heat inside.

Fire Ratings


The final and perhaps most important factor for your sandwich wall panel is the fire rating that it provides. Fire ratings can sometimes be difficult to understand and fully comprehend because regulations may use different measurements to determine their fire ratings. For a full rundown of the difference of our fire ratings, visit Fire Rated Wall Systems: A Beginner’s Guide.

But here's a quick rundown...

Fire Rated Wall Panel
Panel Built's Panel Classifications

Panel Built's standard sandwich panel (gypsum/gypsum) carries with it a Class A rating, meaning it will not sustain a flame, but can possibly ignite. In order to change the fire rating of a wall panel system, you must change the materials the wall panel (and typically the building envelope as a whole) is composed of.

However, for more stringent environments, Panel Built also offers a 1 Hour Fire Rated panel. '1 Hour Fire Rated – Refers to an assembly that can withstand a standardized (ASTM) fire exposure for up to an hour-long. After this, the wall is sprayed with water from a fire hose. If the wall withstands the hosing, the assembly is considered 1 hour fire rated. Panel Built's 1 Hour sandwich panel can still be customized, but will always contain a 2 Inch mineral wool core and a 20 gauge steel stud every 12”.

Between the Class A wall panel and 1 Hour Fire Rated, Panel Built offers a 'Non-Combustible' panel. This is for facilities that would prefer some additional fire protection, but a 1 Hour panel would likely be overkill. This panel has a similar configuration to our 1 Hr panel but uses the 20 gauge steel stud less frequently.

Overall, the amount of fire protection that a sandwich panel will require will largely depend on the environment that it is going into. In facilities that have a large amount of combustible materials & chemicals, a higher level of fire protection is typically required. However, in some cases, local ordinances can demand a higher level of protection. In this case, it can be very helpful to have a knowledgable Panel Built dealer help you determine what fire protection level works best for you.

Modular Offices
Panel Built Building with a Custom Glossy Black Wall Facing

But Why Sandwich Panels?

So far we have talked a lot about what makes up sandwich panels and some of the characteristics that make them different, but why should you choose sandwich panels in the first place? What's the benefit of using this wall system over others?

Mass Production with Customization

The biggest benefit that Panel Built's sandwich panel system provides for you is the cost savings of a mass-produced product that is still able to remain highly flexible.

For the majority of our panel projects, we are able to use the same panel system each time. This panel system can be configured in whichever layout the end customer needs, using our binder-post system to attach them to one another. However, if one of our custom sandwich panels is needed, we are able to quickly substitute the alternate material. Afterwards, the custom panel still fits perfectly into our standard wall panel assembly, minimizing any additional work to fabricate or assemble.

Incredible Convenience at the Job Site

A Modular Office System Mid-Installation

Besides the cost savings passed along to you, sandwich panels are incredibly easy and quick to install at the job-site in comparison to stick-built. With Panel Built, we ship all the wall panels your project will need directly to your job site. The panels are pre-cut and labeled to easily match up with the project's CAD drawing which is provided with each new project. This means our sandwich panels can be erected on-site with no additional fabrication needed on site.

The prefabricated nature of our panel system, your project can be delivered and installed quicker than conventional construction methods. Additionally, with all the fabrication done in our modular construction facility, the job site itself is much cleaner, easier to maintain, and far less disruptive overall.

If you have any questions about our Sandwich Panel System, give us a call at 800.636.3873, send us an email to info@panelbuilt.com, or you can talk to us in our LiveChat feature in the bottom-right of your screen. Our main goal is to Solve your Space Needs With Excellence and Great Customer Service

Sandwich Wall Panel Examples


Wall Panel InstallationModular-Wall-Show-Room











One Hour Fire Rated Panel