Is PVC Foam Board the Same As Foam Board?

Foam board: Delicate outer surfaces—either paper or thin plastic—easily scratched or dented. It’s not waterproof or UV-stable, and prolonged exposure leads to blistering or deformation.

 

What Exactly Are These "Foam Boards"?

 

Foam board, also known as foam-core board or "foamcore", is a lightweight sandwich panel: typically expanded polystyrene foam between thin cardboard or plastic skins. This makes foam board easy to cut with a utility knife, ideal for short-term indoor displays, photo mounting, architectural models, and DIY crafts.

 

HDPE membrane (also called PVC foam sheet, foam PVC, or brands like Sintra/Foamex) is a closed-cell foam made by expanding polyvinyl chloride into a rigid yet lightweight core, sandwiched by a dense PVC outer skin. Unlike polystyrene foam board, PVC foam is dense, smooth, weather- and water-resistant, and suitable for both indoor and outdoor use.

 

 

Surface, Durability & Weather Resistance

 

· Foam board: Delicate outer surfaces—either paper or thin plastic—easily scratched or dented. It’s not waterproof or UV-stable, and prolonged exposure leads to blistering or deformation.

 

· PVC foam board: Hard, scratch-resistant PVC surfaces that withstand moisture, sunlight, and temperature swings. Some grades even include UV stabilizers and fire retardants, making them ideal for signage, outdoor installations, and industrial use.

 

Strength & Machinability

 

Foam board’s polystyrene core is soft—you can easily crush it with your fingers—and it’s best for manual cutting with simple blades.

 

By contrast, PVC foam board is much more rigid. It resists pinching, is suitable for machine/carving work, and can be cut with power tools or CNC. The Celuka-extruded versions feature even harder, smooth skins.

 

Weight, Density & Cost

 

· Foam board is ultra-light—with cores up to 90% air—making it easy to install and move.

· PVC foam board is 3–4× denser/heavier than foam board and usually costs 3–4× as much, with premium grades sometimes costing 5–10× more.

 

Density varies depending on type: PVC foam board typically falls between 0.4–0.8 g/cm³, compared to polystyrene foam board’s much lighter makeup.

 

Application Use Cases

 

Foam Board:

 

· Ideal for indoor, short-term use: signage, exhibits, photo backing, school crafts.

· Used in model aviation, dioramas, prototypes, and cosplay props where light weight matters.

· Unsuitable outdoors—deforms and deteriorates under weather exposure.

 

PVC Foam Board:

 

· Perfect for outdoor applications: signage, billboards, architectural cladding, exhibition walls. With UV-resistant variants, it can "stand for many years".

· Favored for CNC engraving, model making, prop construction, offering clean cuts on machines.

· Also used in industrial, marine, and chemical-proofing settings, thanks to its moisture, chemical, and flame resistance.

 

How They Compare

 

Feature	Foam Board	PVC Foam Board
Core Material	Expanded polystyrene foam	Closed-cell PVC foam
Surface Skin	Paper or plastic	Dense PVC
Weight & Density	Very light, ~90% air	3–4× heavier (~0.4–0.8 g/cm³)
Rigidity & Hardness	Soft, easy manual cutting	Hard, machineable, SUV-resistant
Durability	Short-term indoor use	Long-term, weather-resistant
Water/UV Resistance	Poor; delaminates in moisture	Excellent; resistant to weather & UV
Cost	Low-cost	Medium to high
Common Use Cases	Crafts, model-making, indoor signage	Outdoor signs, CNC projects, cladding

 

When to Choose What

 

1. Choose foam board if you need:

 

· Lightweight, affordable materials for temporary indoor displays or crafts.

· Something easily cut by hand for hobby or school projects.

· Low cost and ease of handling.

 

2. Choose PVC foam board if your project demands:

 

· Outdoor durability—resistance to UV, rain, heat.

· Structural stiffness, scratch resistance, and capacity for precision machining.

· Fire-resistance, chemical stability, and long-term installation.

 

Final Take: Same Shape, Different Substance

 

While both are "foam boards" in form, they’re far from identical:

 

 · Foam board = very light, polystyrene core, indoor-only, cheap, easy to cut.

·  PVC foam board = denser PVC foam, durable, waterproof, machine-friendly, outdoor-ready, pricier.

 

So, no—they are not the same. The name overlaps only in shape, not in material properties.

 

Choosing the Perfect Board

 

Before buying, ask yourself:

 

 · Where will it be used? Indoors or outdoors?

 · How long must it last? Temporary display or permanent structure?

 · Will it be handled or machined? Hand cut vs CNC/carving.

 · What budget do you have? Foam board is low-cost; PVC board commands a premium.

 

By matching material to function—durability, weight, cost—you’ll select the ideal "board" for your specific needs.

 

In summary: While foam board and PVC foam board may look similar, they differ radically in core materials, durability, machinability, weight, weather resistance, and cost. Choose based on your project's performance demands—not just its shape or name.