Page 3 - Doors 101
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?
Structural Differences Between Hollow Metal and Wood Doors
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
Classroom Security, Fire-Rated Corridors, and ADA-Compliant Assemblies for Educational Facilities
This guide answers: Classroom Door Hardware Rules for Lockdown and Egress Compliance
Why School Door Assemblies Require Specialized Configuration
K-12 school buildings present one of the most complex door hardware environments in commercial construction. A single school may require classroom function locksets, fire-rated corridor doors, panic hardware on gymnasium exits, and ADA-compliant entrances — all within the same project. Each opening must satisfy overlapping requirements from fire codes, accessibility standards, security protocols, and the Authority Having Jurisdiction (AHJ).
Errors in specification or hardware selection can delay occupancy permits, create liability during lockdown events, or fail AHJ inspection. Understanding the rules governing each opening type is essential for contractors, architects, and facility managers working on educational facilities.
Classroom Security Hardware
Understanding CDF's production process, lead time factors, and the Fast Track expedited production option.
This guide answers: How Configuration Choices Affect CDF Production Lead Times
CDF's Production Process
CDF fabricates commercial door and frame assemblies at its facility in Nashville, Tennessee. Each order is built to the customer's specifications, including door material, frame profile, hardware preparation, and finish. Because assemblies are configured to order rather than pulled from pre-built inventory, production time is a factor in every order.
CDF's production process includes order verification, material staging, fabrication, hardware preparation, quality inspection, and packaging. Each step is completed before the assembly moves to the next stage.
Factors That Affect Lead Time
Several factors influence the production lead time for a commercial door assembly. Understanding these factors helps contractors plan their project schedules.
Assembly Configuration
Standard configurations
Door, frame, and hardware assemblies for commercial office environments
This guide answers: Office Building Door Configuration Rules by Occupancy Type
Office Building Door Requirements by Occupancy Type
Office buildings are classified primarily as Group B (Business) occupancy under the International Building Code (IBC). However, many office buildings include mixed-use elements — ground-floor retail (Group M), restaurants (Group A-2), parking garages (Group S-2) — each carrying distinct code requirements for door assemblies.
Door selection in office buildings must balance four competing priorities: code compliance, aesthetics, accessibility, and security. Unlike single-use industrial facilities, office buildings require a range of door types across different zones, from glass storefront entries to fire-rated stairwell doors to acoustically rated conference room assemblies.
Entrance and Lobby Doors
Building entrances establish the first impression for tenants and visitors and must meet the
ADA-Compliant, Secure, and Brand-Aligned Aluminum Storefront Systems for Retail Environments
This guide answers: Storefront Door Configuration Rules for Retail ADA and Security
Why Retail Storefront Doors Require Specialized Configuration
Retail storefront entrances must balance multiple requirements: ADA accessibility for all customers, security during closed hours, aesthetic alignment with the brand, and durability under high daily traffic. Aluminum storefront systems are the most common solution, but selecting the correct configuration requires understanding code requirements and available options.
Incorrect storefront door configuration can result in ADA complaints, security vulnerabilities, energy loss, and premature hardware failure.
Aluminum Storefront Door Systems
Aluminum storefront door systems consist of narrow-stile, medium-stile and wide stile doors, and frames. These systems come with a variety of glass options to help you achieve the desired aesthetic and energy saving solution
Understanding CDF's shipping methods, delivery requirements, and freight logistics for commercial door assemblies.
This guide answers: How Shipping Method Selection Affects Lead Time and Damage Risk
Shipping Methods for Commercial Door Assemblies
CDF Distributors ships all orders from its fabrication facility in Nashville, Tennessee. The shipping method selected for each order depends on the size, weight, and quantity of the assemblies being shipped. Selecting the appropriate shipping method helps reduce the risk of freight damage and ensures the order arrives within the expected timeframe.
LTL Freight Shipping
Most commercial door and frame orders ship via LTL (Less-Than-Truckload) freight. LTL carriers transport palletized shipments on shared trailers. This method is standard for full door assemblies, welded frames, and multi-unit orders. LTL shipments are tracked with a PRO number provided at the time of shipment.
UPS and FedEx Parcel Shipping
Smaller items such as knock-down (KD) frames,
Heavy-gauge steel door assemblies engineered for high-traffic industrial environments
This guide answers: How Loading Dock Door Selection Affects Durability and Security
Loading Dock Door Requirements
Warehouse and distribution facilities place unique demands on commercial door assemblies. Loading dock areas experience continuous forklift traffic, pallet jack impacts, and constant opening and closing cycles. Doors in these environments must withstand repeated mechanical stress while maintaining security and code compliance.
High-traffic zones such as loading docks, staging areas, and shipping corridors require heavier-gauge steel doors and reinforced frames. Standard 18-gauge doors are not suitable for areas exposed to equipment traffic. Door assemblies in these locations should be specified with impact resistance, security hardware, and — where required by code — fire-rated labels as primary selection criteria.
Hollow Metal Doors for Warehouse Applications
Hollow metal doors are the standard
A reference guide to how part numbers encode product configuration in commercial door, frame, and hardware distribution
This guide answers: How CDF Part Number Nomenclature Maps to Product Configuration
What Part Numbers Encode in the Commercial Door Industry
In the commercial door industry, part numbers are structured identifiers that encode key product attributes into a single string. A well-designed part numbering system allows anyone in the supply chain — from the estimator to the warehouse worker — to identify exactly what a product is without opening the packaging or looking up a separate document.
Part numbers in the door and hardware industry typically encode some or all of the following attributes:
- Product Category — Whether the item is a door, frame, hinge, lockset, closer, exit device, or accessory.
- Material — The base material such as hollow metal (steel), stainless steel, wood, aluminum, or fiberglass reinforced polyester (FRP).
- Door or Frame Size — The width and height of
Commercial door and hardware terminology covers the specialized vocabulary used across hollow metal doors, steel frames, locksets, hinges, closers, and fire-rated assemblies. This reference guide defines over 100 terms organized by category, giving contractors, facility managers, and specifiers a single resource for understanding the language used in door schedules, hardware specifications, and architectural drawings. Each category below groups related terms so you can quickly find the definition you need during takeoffs, submittals, or field installation.
CDF Distributors provides complete commercial door, frame, and hardware assemblies shipped from its Nashville, Tennessee headquarters. You can configure and order online using CDF’s ProBuilder tool at cdfdistributors.com. For assistance selecting the correct components for your project, call (855) 769-9895 or email sales@cdfdoors.com.
About This Guide
This glossary is compiled from CDF Distributors’ technical documentation, industry
Door handing identifies the swing direction of a commercial door and determines which side receives the hinges, latching hardware, and strike preparation. Every commercial door assembly is manufactured as either left hand or right hand, and swings either inward (standard) or outward (reverse). Correctly identifying door handing before ordering ensures that hinges, locksets, exit devices, and closers are factory-prepared on the correct side of the assembly.
CDF Distributors’ ProBuilder tool at cdfdistributors.com guides handing selection during assembly configuration, displaying visual references for each option. For assistance determining the correct handing for your project, call (855) 769-9895 or email sales@cdfdoors.com.
How to Determine Door Handing
The standard method for determining door handing uses the hinge jamb as the reference point. Stand in the doorway with your back against the hinge jamb (the side where the hinges are or will be mounted). The direction the door opens from