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DE Series Sound Transmission Control Doors

DE-STC (Sound Transmission Control) Acoustical doors reduce unwanted noise. Acoustical performance of building products, components, and systems is an important consideration for engineers, specifiers, and building owners. This is especially true in highly populated cities, areas around highways, railroads, airports, and high density residential zones.

Using the latest sound absorbing techniques and materials, Republic’s engineering professionals have developed a superior sound transmission class (STC) rated assembly consisting of a proprietary core and noticeably lighter weight 1 3/4" door (approximately 25% less than current market products) along with standard “rabbeted” hollow metal frames.

Acoustical door assemblies are available at SDI Levels 3-4, up to 52 STC, and certified to ASTM E90 and ASTM E413.


Strength, durability and ease of installation

  • Sound resistant spectrum (proprietary construction) using a standard 1 3/4" thickness for up to  STC 52 with approximately 25% less door weight than current market products
    • Single flush doors available up to STC 52; Pairs available to STC 47
    • STC 40-47 – furnished with perimeter seals, gaskets and threshold
    • STC 48-52 – furnished with perimeter seals, gasketing, surface mounted auto door bottom, threshold and 5" cam-lift hinges
  • Systems including standard hollow metal frames and a low profile sealing system that is aesthetically pleasing and easy to install
    • Frames available as KD/STC 40 and 42
    • Frames provided as welded/ STC 43-52
  • All doors tested in fully operable conditions by independent third party laboratories

Approvals and specified industry standards

Doors and frame STC systems have been tested to ASTM E90, E413, ASTM E 1332-10a, and ASTM E 2235-04 by independent third party laboratories qualifyed under NVLAP by the National Institute for Science and Technology (NIST), Architectural Testing Inc. and Riverbank Acoustical Laboratories.

Exceeds industry standards

  • Republic is SDI Certified through regular audits to ensure manufacturing, performance and quality standards set by the Steel Door Institute
  • Overall door construction exceeds ANSI A250.8-2017 (SDI-100), the standard set by SDI specifying sizes, design, materials, construction, finishing and performance for standard commercial steel doors and frames
  • SDI Membership communicates compliance with industry standards including ANSI/SDI A250.8, ANSI/SDI A250.10 (Prime paint), ANSI UL 10C (Fire), UL 1784 (Air leakage), ANSI/SDI A250.4 (Physical endurance), ANSI/SDI A250.6 (Hardware reinforcing), ANSI/SDI A250.3 (Finish coatings), ASTM A653 (Galv; All Tornado products are galvanealled), ANSI A115 (Locations) and SDI 117 (Tolerances)
  • Doors meet the broadest fire rating requirements; they are listed for installations requiring compliance to both neutral pressure testing (ASTM E152 and UL-10B) and positive pressure standards (UL-10C)
  • Factory-applied baked-on rust inhibiting primer meets ANSI A250.10-2011

Typical applications

Wherever acoustical performance is required, especially in highly populated cities, areas around highways, railroads, airports and high density residential zones.

Technical Data Guide

For more information, download the Republic Technical Data Manual.

  • DE-STC Series (Pages 27-32), fire rated STC 40 & 42 only (p 98-99), paint (p 117-118), standard hardware locations (p 121-130), specification 08110 (p 131-135, STC 48 p 27, STC 50 & 52 p 28, STC 42, 43 & 47 p 31, STC 40 6-panel emboss p 32). Standard door STC/thermal ratings (p 26)