HDO Plywood - High Density Overlay and Its Uses

Backyard projects often benefit greatly from using plywood due to its versatility. However, it’s crucial to understand the specific type of plywood before purchasing to guarantee the highest quality for your needs. In this article, we explore the exceptional durability and smooth finish of HDO plywood. This type of plywood is ideal for concrete formwork, signage, and various outdoor projects.

What is HDO Plywood?

High Density Overlay (HDO) plywood is created by bonding a fiber surface impregnated with thermosetting resin to one or both sides of the plywood under heat and pressure. This process results in a highly durable panel, making HDO plywood ideal for demanding applications like concrete forming and industrial tanks.

HDO plywood features resin-impregnated fiber faces, making it highly durable and efficient. The pressure and heat process give it a strong, smooth surface that resists abrasion, moisture, deterioration, and chemicals. Compared to traditional plywood, HDO uses more resin, making it ideal for many applications. Additional benefits include dimensional stability, a high strength-to-weight ratio, and rack resistance. HDO plywood is available in various sizes from suppliers and can be worked with common woodworking tools.

> Read more: 20 Types of Wood and Their Uses

HDO plywood

HDO plywood

Important Things To Know About Overlaid Plywood

Overlaid plywood encompasses both high-density (HDO) and medium-density (MDO) variants. Both types employ the standard structure of plywood, with veneer layers tightly bonded together. The overlaid surface of these sheets lends them a polished appearance.

While the exterior of overlaid plywood may not primarily serve decorative purposes, it boasts exceptional durability, providing the panel with a smooth surface that repels water and prevents damage or adhesion of particles. Additionally, it features a protective coating that guards against scratches commonly incurred during construction and transportation, particularly when sourced directly from HDO plywood suppliers.

During manufacturing, the exterior surfaces are bonded to the rest of the veneers through a process involving heat and pressure. HDO plywood panels contain a higher resin content compared to medium-density panels, rendering them slightly pricier. Nonetheless, both variants offer superior durability and strength when compared to traditional plywood.

HDO vs. MDO Plywood: A Comparison

Below is a detailed comparison table between MDO vs HDO plywood

ElementsHDO plywoodMDO plywood
SurfaceHigher density of the exterior fiber layerHigher resin
Thickness3/8”, 1/2″, 5/8”, and 13/8”, 1/2″, 5/8”, and 1
ApplicationHighway panels, industrial tanks, and other highly demanding applicationsIdeal paint base,structural siding, soffits, and other exterior applications
CostHDO plywood price is slightly higher Half and twice the cost of marine plywood and softwood plywood respectively
Available Concrete Form and Industrial GradesConcrete Form and General grades
FinishSmooth “steel-form”Matte

MDO plywood

MDO plywood

Applications of HDO Plywood


HDO is an exceptional product to be used for industrial applications. It is an ideal material for display shelves, bins, and storage racks because it resists dirt penetration, mars, and scuffs. You just need to make sure about the occasional cleaning with a damp cloth to keep its surface smooth and shiny. When it comes to assembling benches and work tables, a smooth surface of HDO plywood makes it the best choice. Other applications of HDO include pallet decks, countertops, drying racks, freezer lockers, humidity chambers, storage lockers, trunks, and other similar controlled atmospheres.

Concrete Forming

One of the best materials for concrete forming, HDO has an exceptionally smooth surface and can be reused many times. It provides high-performance under the alkaline exposures, and it offers consistent curing conditions with its natural insulating quality of plywood.


It was originally created for highway signs, and still very common for large displays and signs. Highway departments and commercial sign shops often consider wholesale HDO plywood for signboards because it can help to carry the message clearly. Moreover, it possesses the properties that are required for large sign installations. Being highly resistant to extreme weather conditions and vandalism, HDO plywood is definitely an ideal choice for signs and other similar uses.


HDO provides exceptional strength to weight ratio that makes it a perfect option for transportation applications. Its armor-like durability makes it ideal for trailer and truck linings. HDO panels can reduce damage and maintenance costs.

HDO Plywood - High Density Overlay and Its UsesHDO Plywood – High Density Overlay and Its Uses

HDO plywood has a longstanding history in signage applications, and its usage has expanded due to its superior performance in various fields. For residents of the USA, sourcing this material from experienced suppliers is crucial to ensure durability and a polished finish. HDO plywood finds application in highway signs, concrete forming, siding, countertops, truck and trailer linings, and cabinets. While it may come at a slightly higher cost than MDO, purchasing wholesale directly from suppliers can offer both cost savings and better shipping options.

Various grades of HDO Plyform may be available; check with your supplier. With reasonable care, HDO Plyform will normally produce 20 to 50 reuses or more. Some concrete-forming specialists achieve 200 or more reuses with good results.HDO plywood, long used in signs, is now gaining popularity for its durability and versatility. For US residents, sourcing from experienced suppliers ensures quality. Ideal for highway signs, concrete forming, siding, countertops, and more, it offers superior durability and smooth surfaces. While slightly pricier than MDO, wholesale options from trusted suppliers offer both cost savings and reliable shipping.