Lynden Door CD200 Commercial Interior Door: 20-Minute Fire Rating With Measurable Performance Specs

The CD200 delivers the specs that matter for commercial projects: 20-minute fire rating with specific size limitations, STC 32 acoustic performance, and WDMA Extra Heavy Duty compliance. This particle board core door meets the demanding requirements of offices, multi-family projects, and institutional buildings where fire separation and sound control aren’t optional.

Fire Rating Performance and Critical Size Constraints

The CD200 earns its 20-minute fire rating through rigorous testing under both positive and neutral pressure conditions. Size matters here — and contractors need to understand the limitations before specifying.

Fire Rating Configuration	Maximum Size	Testing Standard
Positive Pressure	4’ x 9’	UL 10C
Neutral Pressure	3’ x 10’ or 4’ x 9’	UL 10B
Non-Rated	Single: 4’ x 10’; Paired: 8’ x 10’	N/A

The standard 1-3/4” thickness delivers the 20-minute rating. Need vision lites? Total visible light area can’t exceed 1,296 square inches, with maximum individual lite dimensions of 36” wide by 54” tall. Louvers? Forget it — strictly prohibited in 20-minute rated doors.

The door meets NFPA 252 standards. That’s the certification language that keeps code officials happy and projects moving forward.

Sound Control That Works: STC 32 Performance

The CD200 achieves STC 32 acoustic rating through its particle board core construction with a density of 28-32 lb/ft³. That rating comes from ASTM E90-09 testing in non-operable configuration.

Want that same STC 32 rating on an operable door? It’s achievable with specific hardware — think auto door bottoms and perimeter seals like NGP 5075 or Pemko S773. The dense particle board core does the heavy lifting, but the perimeter sealing makes or breaks real-world acoustic performance.

Environmental Compliance Without Compromise

The CD200 meets CARB Phase II and TSCA Title VI compliance. Type 1 waterproof adhesives throughout the construction mean this door won’t delaminate when the HVAC system struggles during Montana’s temperature swings.

FSC® certified particle board core is available on request for projects chasing LEED points. The formaldehyde emission compliance isn’t just a checkbox — it matters in tight commercial buildings where indoor air quality affects occupant health and productivity.

Core Performance: Why Particle Board Beats the Competition Here

Compared to the CD350 or CD450 models with mineral cores for higher fire ratings, the CD200’s particle board core provides better stability against deflection and telegraphing in standard commercial sizes. The bonded sanded core assembly resists warpage and surface telegraphing — problems that plague lesser doors after a few heating and cooling seasons.

Core specs use ANSI A208.1 LD1 particle board standard, with optional LD2 upgrade available. Rails can be mill-option structural composite lumber, wood, or composite material with a minimum 2” pre-trim dimension. Face veneers meet HPVA Architectural ‘A’ grade standards at minimum 1/50” thickness before sanding.

The CD200 is positioned as the “workhorse” of Lynden Door’s commercial line — sitting between residential-grade doors and high-end architectural (LD series) doors. That’s marketing speak for “does the job without unnecessary frills.”

Installation Requirements and Factory Options

Factory prefitting and machining are recommended for all fire-rated doors. This isn’t optional advice — field modifications can void the fire rating. Hardware cutouts should be factory-machined based on manufacturer templates, and fire-rated doors must be glazed under label service if light openings are included.

For 20-minute rated doors, cutouts must maintain at least 6” clearance from any edge or other cutout. Optional inner blocking and lock blocks provide reinforcement for extra-heavy-duty hardware. Stiles come standard in softwood (AWS Type A) with optional hardwood (AWS Type B) matching the face veneer.

The Bottom Line

The CD200 delivers what commercial projects need: certified fire performance, measurable acoustic control, and dimensional stability that lasts. WDMA Extra Heavy Duty compliance means this door handles the abuse of high-traffic commercial environments. The particle board core won’t win beauty contests, but it provides superior resistance to warpage and telegraphing compared to other core types.

For Montana’s growing multi-family sector — where fire ratings and sound control drive door specifications — the CD200 hits the requirements without overbuilding. The 20-minute rating covers most corridor and unit separation requirements, while the STC 32 rating keeps residents happy.

The 5-year limited warranty covers interior use only, with light openings restricted to 40% of the door face or half the door height. Not suitable for exterior applications — Montana’s weather would destroy any interior-rated door regardless of manufacturer.

FAQ

What’s the actual difference between positive and neutral pressure fire ratings? Positive pressure testing (UL 10C) simulates real fire conditions more accurately and limits the CD200 to 4’ x 9’ maximum size. Neutral pressure (UL 10B) allows either 3’ x 10’ or 4’ x 9’ configurations. Most jurisdictions now require positive pressure ratings.

Can I get custom veneers on the CD200? Yes — the door is compatible with AWS Type B wood veneer and a wide range of custom hardwood species. Standard faces use HPVA Architectural ‘A’ grade wood veneer, with options for ‘AA’ grade, MDO, or HDF.

How thick can these doors go? Standard thickness is 1-3/4” for the 20-minute rating, with options up to 2-1/2”. Non-rated versions are available in 1-3/8” thickness. Thicker doors provide better sound attenuation and more substantial feel.

What about factory finishing? UV-cured acrylated polyester/urethane factory finishes are available in both transparent and opaque options. Factory finishing ensures consistent coverage and proper cure before installation.