Concrete Sandwich Panel Insulation: What You Need to Know

Traditionally, a building’s walls are constructed from wood or metal framing, masonry, or concrete (including both cast-in-place or precast options). With these systems, insulation has to be added in a separate step. 

Today, innovative solutions have been added to the range of possibilities for building envelope materials. These unconventional systems combine the structural wall with the insulation so that it can be completed in a single step on the jobsite rather than a series of installations by various contractors. One such solution is the precast insulated concrete sandwich panel wall system.

Let’s learn more about these concrete sandwich panel insulation systems.

What Are Insulated Concrete Sandwich Panels?

Precast concrete insulated sandwich panels are made up of three layers composed of two materials. The exterior and interior layers are made of precast concrete. Sandwiched between the concrete layers, is a single layer of foam insulation. The foam layer can be made of insulation materials including extruded polystyrene (XPS), expanded polystyrene (EPS), or polyiso. 

The overall thickness of a precast concrete insulated sandwich wall panel varies, but is usually between 9 and 17 inches wide. Typically, the exterior-facing concrete layer is thinner, and ranges from two to three inches thick. The interior layer is load-bearing, ranging from 5 inches up to 10 inches in thickness. The insulation can also vary between 2 and 4 inches.

How Concrete Sandwich Panels Are Made

Insulated concrete sandwich panels are manufactured off-site. The process involves several stages:

• First, molds are created. 

• Next, the exterior concrete layer, reinforcement, and connectors are set in place and poured. 

• The insulation layer is added. 

• A thick interior concrete portion is poured to encapsulate the insulation. 

• Once cured, the panels are transported to the jobsite and lifted or tilted into place.

Why Concrete Sandwich Panel Insulation?

There are many reasons that architects, contractors, and building owners choose insulated concrete sandwich panels. 

Here are some benefits of insulated concrete sandwich panels:

Shortens Construction Phase: Precast sandwich panels are pre-assembled off-site, so walls can go up in weeks instead of months.

Thermal Performance: The concrete plus insulation combination provides high thermal resistance and reduces heat loss and energy costs to run HVAC systems.

Structural Security: Concrete provides inherent structural properties.
Reduction in Labor Cost: Precast concrete insulated sandwich panels may cost more up-front, but the labor is reduced since fewer workers can get the walls up in a shorter amount of time when compared to traditional methods.

Fire Resistance: Concrete is naturally fireproof. By encapsulating your insulation between two layers of concrete, your structure’s walls become virtually fireproof.

Durability: Concrete will not only withstand severe weather, but this tough material stands the test of time, to outlast wood or metal building envelopes.

Sustainability: Concrete is a natural and sustainable building material that is environmentally-friendly and that reduces the energy consumption of building heating and cooling systems.

Applications

Some building types are more apt to benefit than others from precast insulated concrete sandwich panel wall systems.

For example, large warehouses can be constructed in a fraction of the time and—once operational—benefit from good thermal efficiency since the concrete wall panels help keep the large interior space temperature-regulated.

Cold storage facilities are another type of facility where precast concrete insulated sandwich wall panels make sense. The added insulation and thermal mass properties of concrete help keep the temperature constant in sensitive environments. 

Many other building types align with these insulated concrete sandwich panels, including:

• Grocery stores 

• Retail spaces

• Agricultural buildings

• Sports facilities

• Schools

These spaces require superior security, energy efficiency, and durability that concrete sandwich panel systems can provide.

Choosing a Concrete Sandwich Panel Insulation

Not all insulated concrete sandwich panels use the same materials. The type of insulation used in these systems can drastically impact the wall system’s effectiveness. For example, using EPS (expanded polystyrene) insulation offers only R-5 per inch, making it R-10 when 2” EPS is used in the panels. 

Polyiso, on the other hand, carries an R-value of R-6 or more per inch. This means that for the same thickness, you can achieve better thermal performance when choosing polyiso over other rigid foam insulations.

Another reason to choose polyiso over other insulations for concrete sandwich panels is that it has a higher resistance to moisture. Since the insulation is directly exposed to moisture during the concrete pouring and curing process, moisture resistance is critical for this application.

Choose a Quality Polyiso

Selecting the best quality wall systems starts with choosing high-performing components. If precast concrete insulated sandwich wall panels make sense for your project—make sure the insulation inside your panels lasts as long as the concrete that encapsulates it. Rmax is proud to offer high-quality polyiso solutions, such as Durasheath® building envelope insulation, for use as a concrete sandwich panel insulation. 

For more information, contact your local representative today!