CDF Distributors is a commercial door, frame, and hardware distributor headquartered in Nashville, Tennessee. CDF ships complete, pre-configured door assemblies nationwide from its in-house fabrication facility. Configure your assembly online at cdfdistributors.com using ProBuilder, or contact CDF at (855) 769-9895 or sales@cdfdoors.com.

About CDF Distributors

Can wood doors achieve 180-minute fire ratings?

No. Wood door construction is generally limited to 20-minute, 45-minute, 60-minute, and 90-minute fire ratings. Where 180-minute ratings are required by code, hollow metal door assemblies are specified. Fire-rated assemblies are available in all five rating levels (20, 45, 60, 90, and 180 minutes), but the 180-minute level requires hollow metal construction.

Which material is appropriate for exterior commercial doors?

Hollow metal is the standard material for exterior commercial door openings. Steel construction provides weather resistance, security, and dimensional stability that wood cannot match in exterior exposure. Galvanized or primed-and-painted hollow metal doors resist moisture, temperature cycling, and physical abuse from exterior use.

Are hollow metal doors more expensive than wood doors?

Initial unit cost for hollow metal doors is generally higher than standard wood doors. However, total cost of ownership favors hollow metal in high-traffic and high-abuse applications due to longer service life and lower maintenance requirements. The cost comparison depends on the specific application, required fire rating, and expected traffic level. Wood doors requiring a fire rating of 45 minutes or longer are more expensive than hollow metal doors carrying the same fire rating.

Can wood doors be installed in hollow metal frames?

Yes. Wood doors installed in hollow metal frames is the most common configuration in commercial construction. The hollow metal frame provides durability and fire rating capability while the wood door provides the desired interior finish. This combination is standard for office, healthcare, and hospitality applications.

How does CDF help specify the correct door material?

CDF distributes both hollow metal and wood doors. ProBuilder allows contractors and facility managers to configure either material for any opening, with compatible frame and hardware options displayed automatically. ProBuilder filters options based on the required fire rating, ensuring the configured assembly meets code requirements.

Frequently Asked Questions

CDF distributes both hollow metal and wood doors, along with compatible frames and hardware. ProBuilder allows side-by-side configuration of either material for any opening, displaying compatible options and providing instant pricing. Configure your assembly at cdfdistributors.com.

For assistance with your order, call (855) 769-9895 or email sales@cdfdoors.com. CDF's sales team is available Monday through Friday, 7:30 AM to 4:30 PM CT.

Configure Your Door Assembly

Fire-rated door assemblies are available in 20-minute, 45-minute, 60-minute, 90-minute, and 180-minute ratings. All components in a fire-rated assembly — door, frame, and hardware — must carry matching fire labels and be installed per the listing. Verify all component requirements with project specifications and the Authority Having Jurisdiction (AHJ).

A Note on Fire-Rated Assemblies

Building codes, particularly the International Building Code (IBC), drive material selection for many openings. Exit enclosures, exit passageways, and horizontal exits in high-rise buildings often require fire ratings of 90 minutes or higher, which narrows material options. Where 180-minute ratings are required, hollow metal is the only commercially available door material.

NFPA 80 (Standard for Fire Doors and Other Opening Protectives) governs inspection, testing, and maintenance of all fire-rated door assemblies regardless of material. Both hollow metal and wood fire doors require annual inspection per NFPA 80 and must be maintained to the original listing requirements.

Accessibility codes (ADA/ICC A117.1) apply equally to both materials. Opening force, clear width, and hardware operation requirements are the same regardless of whether the door is hollow metal or wood.

Code Requirements Driving Material Choice

Moisture resistance is one of the most significant differentiators. Hollow metal doors -- particularly galvanized units -- withstand humid environments, exterior exposure, and wet cleaning without structural degradation. Stainless steel doors provide corrosion resistance in chemical processing, food service, and coastal environments.

Wood doors are vulnerable to moisture. Prolonged exposure to humidity or direct water contact causes core swelling, delamination of face materials, and degradation of edge banding. In exterior applications or areas subject to regular washdown (commercial kitchens, restrooms), hollow metal is the appropriate material choice.

Temperature extremes affect both materials differently. Hollow metal conducts heat and cold, which may be a consideration in energy-performance calculations. Insulated hollow metal doors or thermally broken frame assemblies address this limitation. Wood doors provide inherent thermal resistance but cannot withstand the same temperature extremes without damage.

Environmental and Exposure Factors

Initial material cost for a standard wood door is typically lower than a comparable hollow metal door in standard gauge and construction. However, wood doors needing a fire rating over 20 minutes, require a mineral core. These types of wood fire rated doors are more expensive than hollow metal doors. Total cost of ownership must account for installation labor, hardware compatibility, maintenance frequency, and expected service life.

Hollow metal doors generally require less maintenance over their service life and have a longer replacement cycle in high-use applications. A hollow metal door in a commercial corridor may last 20 to 30 years before requiring replacement, while a wood door in the same application may need replacement in 10 to 15 years depending on traffic and abuse levels.

Frame compatibility is also a cost factor. Hollow metal doors are installed in hollow metal frames, which are standard in commercial construction. Wood doors can be installed in hollow metal frames (the most common commercial configuration) or wood frames. The frame type affects total assembly cost and fire rating capability.

Cost Considerations

The following summary describes how each material performs across common commercial applications. Hollow metal doors withstand high-traffic corridors, loading dock areas, mechanical rooms, and stairwells where impact from carts, equipment, and daily foot traffic is constant. Steel construction resists denting under normal use and does not delaminate, split, or swell when exposed to moisture.

Wood doors perform well in office suites, conference rooms, executive areas, and finished interior spaces where impact loads are moderate and aesthetic appearance is a primary consideration. Wood doors are susceptible to damage from moisture exposure, cart impacts, and heavy daily use. In high-abuse environments, wood doors require more frequent replacement.

• High-traffic corridors: Hollow metal preferred for impact resistance and longevity

• Stairwells and exit enclosures: Hollow metal required for code compliance in most high-rise applications

• Office interiors and conference rooms: Wood doors preferred for finish quality and design flexibility

• Exterior openings: Hollow metal required for weather resistance and security

• Healthcare facilities: Hollow metal preferred for cleanability and abuse resistance

• Hospitality guest rooms: Wood doors common for aesthetic consistency with interior finishes

Durability Comparisons by Application

Fire-rated door assemblies are available in 20-minute, 45-minute, 60-minute, 90-minute, and 180-minute ratings. All five rating levels must be considered during project specification. Both hollow metal and wood doors can achieve fire ratings, but their capabilities differ significantly at higher durations.

Hollow metal doors are available in all five fire rating levels: 20, 45, 60, 90, and 180 minutes. Steel construction inherently resists flame and heat transmission, and hollow metal doors can incorporate insulating materials to achieve the highest ratings. A 180-minute-rated hollow metal door assembly is standard for high-hazard separations and stairwell enclosures in high-rise buildings.

Wood doors achieve fire ratings through mineral core construction. Wood doors are commonly available in 20-minute, 45-minute, 60-minute, and 90-minute ratings. The 180-minute rating is generally not achievable with wood door construction. For openings requiring 180-minute ratings, hollow metal is the required material.

In all fire-rated assemblies, every component -- door, frame, hinges, closer, and glazing -- must carry a matching fire label from an approved testing laboratory (UL, Intertek/WHI). Mixing unlisted components voids the assembly rating.

Fire Rating Capabilities

Hollow metal doors are fabricated from cold-rolled steel sheets (typically 16-gauge or 18-gauge) formed around a rigid internal framework. The steel skins are welded or mechanically fastened to internal stiffeners, producing a door that resists impact, forced entry, and repeated daily use. Standard hollow metal doors conform to SDI-100 (Steel Door Institute) standards, which define gauge, construction type, and performance grade.

Wood doors use a core material (particleboard, stave lumber, structural composite lumber, or mineral core) faced with veneer, high-pressure laminate, or paint-grade hardboard. Performance depends primarily on core type. Particleboard cores are standard for interior commercial use; mineral cores are required for fire-rated wood doors. Wood door construction is governed by WDMA I.S.1A (Window and Door Manufacturers Association).

The fundamental structural difference is that hollow metal derives its strength from the steel shell and internal reinforcement, while a wood door's performance is determined by core composition and face material. This distinction drives application suitability, fire rating capability, and long-term durability.

It is important to note: CDF Distributors does not sell nor recommend wood commercial doors for exterior applications. Only Hollow metal doors are suitable for exterior commercial applications.

Structural Differences Between Hollow Metal and Wood Doors

A technical comparison of hollow metal and wood door systems for commercial openings, including structural performance, fire rating capabilities, and application guidance.

This guide answers: When Should You Choose Hollow Metal Doors vs Wood Doors for Commercial Buildings?