709:, ceiling tiles made from mineral fibres, plastic, tin, composite, or fire-rated wood panels can be used within the construction to meet acceptable standards/ratings. Some tiles, in specific situations, can provide the needed additional resistance to meet the "time rating" required for various fire code, city ordinance, commercial, or other similar building construction regulations. Fire ratings for ceiling panels vary based on the materials used, the preparation of each panel, and the safety testing and third party evaluation done to determine where and how they can be safely installed. In the United Kingdom, tiles from certain manufacturers may be required to be clipped into the grid with special ceiling clips to provide a fire rating; there are special tiles designed for the underside of mezzanine floors however that can give a fire rating without being clipped.
648:
519:
684:
in a plenum space, inside a metallic container. Similarly, electrical outlets for domestic powered devices may not be inside the plenum space, but outlets can be installed on ceiling tiles inside electrical boxes, with the sockets exposed on the exterior bottom face of the drop ceiling. The purpose of these restrictions is to limit flame spread inside the unseen plenum space, in the event of high voltage equipment or wiring failure. Low-voltage cabling is permitted because current flow is typically negligible and so the risk of overheating and fire is limited.
757:
30:
504:
632:
22:
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technologies more difficult to appreciate. It is also more difficult to perform maintenance on or diagnose problems with the concealed systems. It is common practice in commercial and office settings to install drop ceilings in older buildings which were not designed for modern HVAC, electrical, or fire suppression systems in mind. These renovations are oftentimes criticized for covering up aesthetically appealing structural elements of older buildings.
749:
475:
765:
obstruction and the level of the ceiling grid. A direct-mount grid may work for those who want the convenience of a dropped ceiling but have limited headroom. Stretch ceiling supports require less than 25 mm (1 in) of vertical space, and no space is required for tiles to be lifted out with a stretch ceiling, but a greater clearance space may be chosen to allow room for MEC or for aesthetic reasons.
1173:
495:
ceiling is becoming increasingly more difficult as the demand for them and the production of parts slow. Small clips are still available that allow tiles to be inserted into gaps in the ceiling where a tile is missing and work by being placed on the edge of a concealed tile and then being slid along as the tile is placed to "lock" it in place.
121:
starting at the edge of the ceiling, or at a designated "key tile", and then removing contiguous tiles one at a time until the desired place of access was reached. Once the repair or inspection was completed, the tiles had to be reinstalled. This process could be time-consuming and expensive. On
September 8, 1958, Donald A. Brown of
129:. This invention provided suspended ceiling construction in which access may readily be obtained at any desired location. Patent Number US 2,984,946 A was granted on May 23, 1961. Brown has sometimes been credited as being the inventor of the dropped ceiling even though other patents preceded his, as shown in the table below.
491:
allowing for the other panels to be slid out of the grid (a series of metal channels called "z bars") one by one, until eventually removing the desired panel. This type of ceiling is more commonly found in older installations or installations where access to above the ceiling is generally considered unnecessary.
735:
In office buildings, drop ceilings are often used in conjunction with hollow steel studs to construct small office spaces out of a much larger cavernous space. Wiring and other services are run through the open ceiling, down through the hollow stud walls, and to outlets in the work areas. If business
596:
The following standards are in addition to those for ceiling tiles in general. No clips, fasteners, or impediments of any kind can be used to limit the ceiling tile's ability to drop from the suspension system without restraint in the event of a fire unless they have been used in the testing process.
355:
The acoustic performance of suspended ceilings has improved dramatically over the years, with enhanced sound absorption and attenuation. This is sometimes achieved by adding insulation known as Sound
Attenuation Batts (SABs), more commonly referred to as "sound batts", above the panels to help deaden
772:
As a renovation tool, dropped ceilings are a quick and inexpensive way to repair a ceiling and to reduce HVAC costs. Some materials may show their age quickly. For example, mineral fiber sags are damaged easily when handled and stain easily and permanently, but stretch ceiling, tin, and vinyl do not
727:
Wiring and piping installed behind traditional plaster or wallboard ceilings are extremely difficult to modify once the finished ceiling is in place. Wires must be fished through hollow spaces in the walls behind the finished ceiling, or the ceiling must be demolished for changes to wiring or piping
692:
only by gravity may become unseated, swing down on their armorflex power cables, and hit the firefighters below. Binding the fixtures to the framework assures that if the framework must be pulled down, the fixture will come down with it and not become a pendulous swinging hazard to the firefighters.
687:
In earthquake prone areas, such as
California, diagonal wire stays are often required by building codes to prevent the ceiling grid from swaying laterally during an earthquake, which can lead to partial or total collapse of the ceiling grid on the occupants below during a severe tremor. Compression
683:
High-voltage electrical equipment (generally regarded as being over 50 V) is not permitted to be exposed in the plenum space above a drop ceiling but must be enclosed in conduit or raceways and be physically isolated from low-voltage wiring. High-voltage electrical devices similarly must be enclosed
425:
A typical dropped ceiling consists of a gridwork of metal channels in the shape of an upside-down "T", suspended on wires from the overhead structure. These channels snap together in a regularly spaced pattern of cells. Each cell is then filled with lightweight ceiling tiles or "panels" which simply
715:
have a further advantage since they can be mounted underneath fire sprinklers, thus hiding the sprinklers for a more attractive appearance. When they are installed under fire sprinklers, materials, applications, installation, and maintenance of drop out ceilings may be necessary to comply with fire
385:
Energy efficiency, including daylight efficacy and thermal insulating qualities. This uses the ceiling plane to reflect daylight as well as electrical illumination to maximize lumen efficacy, which also improves the comfort and usability of interior spaces. A common measure of the light reflectance
120:
U. S. Patent No. 1,470,728 for modern dropped ceilings was applied for by E. E. Hall on May 28, 1919, and granted on
October 16, 1923. Initially modern dropped ceilings were built using interlocking tiles and the only way to provide access for repair or inspection of the area above the tiles was by
663:
If the dropped ceiling is used as a plenum, low-voltage cables and wiring that are not installed inside conduit must use a special low-smoke and low-toxicity wire insulation, which will tend to char and stop burning on its own. That helps to protect building occupants so that they are not poisoned
764:
One disadvantage with this ceiling system is the reduced headroom. Clearance is required between the grid and any pipes or duct work above to install the ceiling tiles and light fixtures. In general, a minimum clearance of 100 to 200 millimetres (4 to 8 in) is often needed between the lowest
691:
Lighting fixtures and other devices installed in a dropped ceiling must be firmly secured to the dropped ceiling framework. A fire above a dropped ceiling often requires firefighters to pull down the ceiling in a hurry for quick access to the conflagration. Loose fixtures resting in the framework
607:
556:
When a stretch ceiling is being installed, semi-concealed plastic/aluminum track, the preferred choice for most architects and designers, is cut to size and fixed to the perimeter of the ceiling area. The membrane is stretched and the harpoon or catch edge is clipped into the track. Stretching is
1056:
343:
For many years, dropped ceilings were made of basic white tiles, but modern innovations now offer a plethora of options in sizes, colors, materials (including retro designs and faux leather, wood, or metal), visual effects and shapes, patterns, and textures as well as support systems and ways to
490:
panels into one another and the grid with the use of small strips of metal called 'splines', thus making it difficult to remove panels to gain access above the ceiling without damaging the installation or the panels. Normally, they have a "key panel" (usually in the corner) that can be removed,
494:
This system has some major disadvantages, compared to the more common "drop panel" system, most notably the difficulty in removing and reattaching panels from the grid, which, in some cases, can cause irreparable damage to the panels removed. Finding replacement panels for this type of dropped
768:
Dropped ceilings generally conceal many of the functional and structural elements of a building, which creates an aesthetic paradigm that discourages the use of functional building systems as aesthetic design elements. Concealing such elements makes the complexity of today's advanced building
731:
In contrast, the tiles and other parts of a dropped or stretch ceiling can be easily removed to allow access to the area above the grid to do any necessary wiring or plumbing modifications. In remodeling, nearly all components of the grid can be dismantled and reassembled elsewhere.
339:
above the dropped ceiling, while allowing access for repairs and inspections. Drop ceilings may also be used to hide problems, such as structural damage. Further, drop out ceilings can also conceal the sprinkler systems while still providing full fire suppression functionality.
405:(MEP) is important with dropped ceilings, since most of these systems are by definition above the ceiling. Most ceiling system products are now designed with this integration in mind. Decisions here can also affect aesthetics as well as access and maintenance.
739:
In older buildings that have had multiple renovations, a dropped ceiling has often been installed in one renovation and then subsequently removed in another since its installation having been an inexpensive fix to prolong the time between major renovations.
514:
With similar advantages to a dropped ceiling, a stretch ceiling is often used to conceal pipework, wires or the existing ceiling. There is also usually a broad choice of colour or texture, and the membrane can be manipulated into a variety of shapes.
659:
for ventilation systems, requiring only enclosed ducts that deliver fresh air into the room below, with return air entering the ceiling space through open grilles across the ceiling. That practice is now used less frequently in new buildings.
314:
Effective building design requires balancing multiple objectives: aesthetics, acoustics, environmental factors, and integration with the building's infrastructure—not to mention cost of construction as well as long-term operation costs.
453:
and its neighboring countries, the cell size in the suspension grids is typically either 2 by 2 feet (610 mm × 610 mm) or 2 by 4 feet (610 mm × 1,220 mm), and the ceiling tiles, light fixtures, and
664:
with toxic chemicals sucked through the ventilation system during a fire, and it helps to prevent fires from spreading inside the hidden plenum space. The special low-smoke cable is typically referred to as
569:
because the tiles, sometimes called melt-out ceiling tiles, are heat-sensitive and are designed to fall from the dropped ceiling suspension grid during a fire, allowing the sprinklers to spray their water.
780:
for its insulating and fire-resistant properties. These can pose a serious health hazard to occupants and especially workers if the asbestos-containing elements are not properly removed.
462:, the cell size in the suspension grids is 600×600 mm, while the ceiling tiles and fixtures are slightly (5 mm) smaller at 595×595 mm or 595×1195 mm, and the
352:
Acoustic balance and control was another early objective of dropped ceilings. A noisy room can overstimulate occupants, while a too quiet interior may seem dull and uninviting.
651:
A plenum created by accident can go unnoticed and become a fire hazard, due to cabling being installed under the assumption that this will always be a non-plenum airspace.
1142:
1076:
724:
Another advantage of a dropped ceiling is that the easily removed ceiling panels offer instant access to the plenum, which greatly simplifies repairs or alterations.
373:
emissions, lighting and thermal system control, thermal comfort, use of daylight for natural illumination, acoustics, and optimization of outdoor view availability.
1150:
552:– This is ultrasonically welded to the edge of the membrane or sheet in the factory, the edging slots into the perimeter track to keep the ceiling in place.
546:– Typically a PVC or nylon material, lightweight sheets are made to size/shape from roll material. Can be printed or painted to achieve the desired effect.
221:
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891:
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of a ceiling material is ASTM E 1477 for Light
Reflectance (LR-1). A level of about 75% is considered good, although higher levels are possible.
866:
752:
A panel broken from removal. The panel to the upper right shows the characteristic brown stain from saturation with water (roof or pipe leak).
573:
Drop out ceiling tiles can add to the aesthetic appeal of a ceiling since the fire sprinklers are hidden by the tiles. Commonly made from
989:
Life Cycle
Analysis: Wall-to-Wall Ceilings and the Open Plenum--Energy Savings and Other Benefits of Suspended Ceilings vs. Open Plenum
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needs change, the office spaces can be easily dismantled, with the overall cavernous space reconfigured with a different floor plan.
217:
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1104:
619:
402:
381:
Many manufacturers of modern dropped ceilings include sustainability as an objective. Sustainable features may include:
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access the plenum. Custom runs of specialty ceiling tiles can be done at relatively low cost compared with the past.
923:
585:
1001:
899:
581:, drop out ceiling tiles are available in multiple sizes and finishes from a variety of manufacturers.
565:
Approved drop out (or drop-out) ceilings allow the installation of a dropped ceiling beneath existing
988:
938:
370:
216:
First integration of tiles and grid. Wong founded Cepco
Manufacturing, a company later absorbed into
835:
1119:"Thermoformed Ceiling Panels and Tiles: Drop-out Ceiling Panels Installed Beneath Fire Sprinklers"
813:
1144:
Thermoformed
Ceiling Panels and Tiles: Drop-out Ceiling Panels Installed Beneath Fire Sprinklers
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are shorter by 37 mm to allow for easier and safer insertion and removal without breakage.
957:
800:
Interview with
Matthew Welch, Curator of Japanese and Korean Art, Minneapolis Institute of Arts
669:
323:
Modern dropped ceilings were initially created to hide the building infrastructure, including
588:
and, in the United States, must meet the standards listed in the section below at a minimum.
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688:
posts may also be added to keep the ceiling from bouncing vertically during an earthquake.
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8:
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Owing to their popularity in the mid-20th century, many older drop ceilings incorporated
647:
526:
A stretch ceiling is a suspended ceiling system and it is made of three main components:
463:
110:
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25:
Dropped ceiling featuring ceiling tiles, lights, air diffusers, smoke detector, and more
1198:
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Sign warning about low clearance due to reduced headroom causing risk of head injury
676:
cable for networking and telephone service is the most common form of plenum cable,
106:
102:
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945:
566:
508:
114:
1147:, The Construction Specifier Magazine, 2014 (especially the Maintenance section)
29:
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503:
122:
1187:
1161:
by Ed Davis and
Michael Chusid, Consulting-Specifying Engineer Magazine, 2016
1155:
by Ed Davis and Michael Chusid, Consulting-Specifying Engineer Magazine, 2016
677:
631:
450:
45:, hung below the main (structural) ceiling. It may also be referred to as a
655:
In older buildings, the space above the dropped ceiling was often used as a
597:
Painting can void an approval, and additional local requirements may exist.
673:
665:
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82:
78:
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332:
86:
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285:
Supporting Electric Lighting Fixture from Suspended Ceiling Framework
601:
534:
487:
21:
616:– AC-12 Section 4.4 – Foam Plastic Drop-Out Ceiling Panels and Tiles
777:
879:
Patent US 2,984,946 A - Accessible Suspended Ceiling Construction
42:
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459:
328:
324:
591:
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drop into the grid. The primary grid types are "Standard 1" (
98:
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aided by heating up the membrane or sheet prior to fitting.
478:
Interlocked panels can be "slid" across and out of the grid.
1105:
NFPA 13: Standard for the Installation of Sprinkler Systems
105:(1337 to 1573). These could be made with simple planks, or
1002:"HOME DZINE Home Improvement – What is a stretch ceiling?"
613:
538:
1020:"Approval Standard for Plastic Suspended Ceiling Panels"
522:
White matte stretch ceiling in a residential living room
117:, built in 1596, had dropped ceilings to aid acoustics.
1116:
389:
Reduced resources needed for construction of the tiles
482:
An older, less common type of dropped ceiling is the
1152:
Specifying Drop-Out Ceilings beneath Fire Sprinklers
622:– Standard for the Installation of Sprinkler Systems
604:– Approval Standards for Plastic Suspended Ceilings
369:Indoor environmental quality includes ventilation,
133:U. S. dropped ceiling patents to September 8, 1958
892:"Don Brown remembered as a man with lots of ideas"
396:
1185:
97:Dropped ceilings and ceiling tiles were used in
811:
635:A commercial building without a plenum airspace
364:
33:Dropped ceiling with ceiling tile light fixture
507:Stretch ceiling installation over an existing
643:A commercial building with a plenum airspace
1057:"Ceiling Panels for Use Beneath Sprinklers"
924:New Trends in Ceiling Designs and Materials
610:– Ceiling Panels for Use Beneath Sprinklers
16:Secondary ceiling hung below a main ceiling
850:The Acoustic World of Early Modern England
680:also needs to be plenum-rated for safety.
592:Drop out ceiling standards (United States)
199:First fully developed grid system concept
127:Accessible Suspended Ceiling Construction
1159:Safety, Code Issues of Drop-Out Ceilings
963:
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862:
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812:Edward S. Morse (1885). "1: The House".
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356:sounds and keep adjacent rooms quieter.
28:
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413:Dropped ceilings may have an improved
101:for aesthetic reasons as early as the
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815:Japanese Homes and their Surroundings
584:Installation is subject to the local
392:Recyclable/reused/renewable materials
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560:
403:mechanical, electrical, and plumbing
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237:Suspended Ceiling Grid Construction
586:Authority Having Jurisdiction (AHJ)
420:
13:
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970:Let us Talk about Dropped Ceilings
898:. January 19, 2010. Archived from
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14:
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939:Ceiling Technology and Aesthetics
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446:-inch grid), and concealed grid.
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1081:. ICC. p. 5. Archived from
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486:system, which uses a method of
397:Integration with infrastructure
196:Suspended Ceiling Construction
958:Suspended Ceiling Construction
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872:
842:
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1:
783:
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318:
301:Accessible Suspended Ceiling
89:and commercial applications.
1117:The Construction Specifier.
1107:, retrieved January 15, 2014
1095:, retrieved January 15, 2014
1078:AC12 Foam Plastic Insulation
1065:, retrieved January 15, 2014
1046:, retrieved January 15, 2014
991:, retrieved January 15, 2014
979:, retrieved January 15, 2014
960:, retrieved January 15, 2014
948:, retrieved January 15, 2014
926:, retrieved January 15, 2014
881:, retrieved January 12, 2014
869:, retrieved January 14, 2014
854:, retrieved January 14, 2014
802:, retrieved January 12, 2014
672:(LSZH or LS0H) cable. While
464:T5 fluorescent and LED tubes
458:tubes are the same size. In
365:Indoor environmental quality
347:
7:
852:by Bruce R. Smith, page 216
773:have such characteristics.
10:
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77:and is a staple of modern
975:January 18, 2014, at the
944:January 18, 2014, at the
417:(ROI) over open ceilings
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253:Suspended Ceiling System
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180:Suspended Ceiling Hanger
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125:, filed for a patent for
1061:Underwriter's Laboratory
867:Suspended Ceiling Patent
436:-inch face), Slimline (
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670:Low Smoke Zero Halogen
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360:Environmental factors
32:
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1180:at Wikimedia Commons
720:Ease of modification
716:safety regulations.
579:expanded polystyrene
415:return on investment
1085:on January 16, 2014
896:The Morning Journal
193:Bibb, Remmen, Bibb
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111:Blackfriars Theatre
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292:September 8, 1958
269:Suspended Ceiling
204:December 13, 1955
171:September 3, 1931
164:Suspended Ceiling
132:
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1176:Media related to
902:on March 31, 2012
713:Drop out ceilings
561:Drop out ceilings
456:fluorescent light
401:Integration with
310:Design objectives
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276:February 7, 1958
260:October 25, 1956
222:Empire West, Inc.
187:October 24, 1950
59:suspended ceiling
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1075:ICC-ES (2012).
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55:false ceiling
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51:T-bar ceiling
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31:
23:
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1124:November 14,
1122:. Retrieved
1112:
1100:
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1083:the original
1077:
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1031:the original
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895:
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728:to be made.
726:
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674:twisted pair
666:plenum cable
662:
657:plenum space
654:
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83:architecture
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63:grid ceiling
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47:drop ceiling
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1089:January 15,
1040:January 15,
906:January 14,
707:fire safety
705:To address
701:Fire safety
537:or plastic
141:Patent no.
138:Date filed
87:residential
1188:Categories
784:References
696:Advantages
319:Aesthetics
295:2,984,946
279:2,963,251
263:2,895,180
247:2,894,291
231:2,896,752
207:2,816,623
190:2,710,679
177:Danielson
174:1,931,574
158:1,470,728
144:Applicant
1199:Acoustics
1027:FM Global
834:ignored (
824:cite book
602:FM Global
535:Aluminium
348:Acoustics
331:, and/or
250:Sorenson
150:Comments
1194:Ceilings
973:Archived
942:Archived
778:asbestos
544:Membrane
333:ductwork
266:Byssing
107:coffered
85:in both
620:NFPA 13
449:In the
441:⁄
431:⁄
218:Ceilume
93:History
43:ceiling
614:ICC-ES
460:Europe
329:wiring
325:piping
298:Brown
234:Wilde
147:Title
1034:(PDF)
1023:(PDF)
575:vinyl
282:Fuss
210:Wong
161:Hall
99:Japan
73:, or
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409:Cost
81:and
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577:or
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