This document discusses different types of ceilings. It describes tin ceilings, dropped ceilings, coffer ceilings, popcorn ceilings, gypsum ceilings, and acoustic ceilings. Tin ceilings were an affordable alternative to plasterwork and were formed by pressing patterns into metal. Dropped ceilings use a grid of metal channels to hold acoustic tiles. Coffer ceilings are recessed panels that serve as decorative elements. Popcorn ceilings provided acoustic benefits but are no longer commonly used. Gypsum is a material used in some ceiling types due to its hardening properties. Acoustic ceilings aim to absorb or redirect sound using perforated materials.

1. CEILINGS AND TYPES
DEVESH TRIPATHI
B-ARCH 4TH YEAR

2. INTRODUCTION
A ceiling is an overhead interior
surface that bounds the upper limit
of a room Generally not a
structural element, but a finished
surface concealing the underside of
the floor or roof structure above

3. TYPES OF CEILINGS
 1} TIN CEILINGS
 2} DROPPED CEILINGS
 3} COFFER CEILINGS
 4} POPCORN CEILINGS
 5} GYPSUM CEILINGS
 6} POLYTONE CEILINGS
 7} ACOUSTIC CEILINGS

4. TIN CEILINGS
 Historically, tin ceilings were introduced
to North America as an affordable
alternative to the exquisite plasterwork
used in European homes. Using this
method of production, metal was
sandwiched between two interlocking
tools. The top tool, or "ram," was lifted
up by a rope or chain, then dropped
down onto the bottom die, smashing
into the metal that was underneath and
permanently embedding intricate
patterns into the tin .

5. DROPPED CEILINGS
 In construction and architecture, a dropped
ceiling, also referred to as a drop or suspended
ceiling, is used as a secondary ceiling formed to
conceal piping ,wiringorductwork, into an area
called the plenum, Consisting of a grid-work 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 - typically a 2x2 or 2x4
foot grid in the US or 600 x 600 mm grid in
Europe - and each cell is filled with lightweight
"acoustic ceiling tiles" or "panels" which simply
drop into the grid .

8. COFFER CEILINGS
 In architecture, a coffer (plural: coffering) is a
sunken panel in the shape of a square,
rectangle, or octagon that serves as a
decorative device, usually in a ceiling. An
example of this can be found in the ceiling of
the rotunda dome in the Roman pantheonIn
fortification, a coffer was a hollow lodgment,
against a dry moat, from six to seven feet deep,
and from sixteen to eighteen feet broad; the
upper part being made of pieces of timber
raised two feet above the level of the moat. The
besieged generally made use of these coffers to
repulse the besiegers, when they tried to pass
the ditch

10. POPCORN CEILINGS
 Popcorn ceiling is a term for a spray-on or
paint-on acoustic ceiling treatment often used
in the 1960s and 1970s in American residential
construction. Its bright white cottage cheese
texture, often with small bits of gold-colored
glitter attached, was good at covering poor
workmanship in the attachment and taping of
the drywell and helped eliminate echoes and
reflected sound. It was also quickly and easily
applied in new construction. It was often the
standard for bedroom and residential hallways
ceilings, while kitchen and living rooms ceilings
would normally be textured in smoother skip-
trowel or orange peel texture.

11. GYPSUM CEILINGS
 Gypsum is a non hydraulic binder occurring
naturally as a short crystalline rock or sand .pure
gypsum is white transcluent crystalline mineral
and is so soft that it can be scratched by a figer
nail when heated to 205*c ,pure gypsum loses
its luster and its specific gravity is increased from
2.3 to 2.95 due to loss of water of crystallization
The setting and hardening of gypsum are due
to intergrowth of very fine and a poorly soluble
crystals of dehydration of gypsum as they
precipitate from a solution which remains
oversaturated as long as the hydration of
gypsum proceed.

12. ACOUSTIC CEILINGS
 Figure 1. As an example of the first application,
the curved surfaces above the stage of the
Orpheum Theatre, Vancouver, B.C., are made of
finely perforated metal sheet, not of plaster as
they appear. The perforations allow the sound
to pass through and to reflect back into the
hall at desired locations, from specially designed
surfaces behind the perforated metal.
 There are three principal acoustical
applications for perforated metals:

13.  1. As a Facing for Something Else
Here the perforated metal is used as a
protective or decorative covering for some
special acoustical material; that material may be
designed either to absorb sound or to reflect or
scatter sound in a special way. It is this special
material that does the actual acoustical work, so
the purpose of the perforated metal in such
applications is to "disappear" acoustically: that
is, it must be so trans parent that the sound
waves can pass right through it to encounter
the acoustical treatment that lies behind. Our
design goal in this case is to choose the
perforated metal for greatest sound
transparency, for sounds of all frequencies.

14.  2. In Tuned Resonant Sound Absorbers
Sometimes, however, we may wish to
absorb sound very selectively, only in a
certain band of frequencies but not at
frequencies lying above and below that
band. For this purpose we design a so-
called Resonant Sound Absorber. Here,
the perforated metal, instead of
disappearing, takes an active part in
tuning the absorber, that is, in
determining which frequencies of sound
are absorbed

15.  3. As Airflow Diffusers
In the acoustical treatment of certain specialized
aerodynamic test facilities, such as wind tunnels,
perforated metals are often used to break up the
turbulence in airflows. This last application is both
specialized and highly technical. Moreover, it does not
represent a significant portion of the market; therefore,
the rest of this book will be concerned entirely with the
first two applications.
 The main text of this book is intended for readers with
no special technical background. It is divided into two
parts. The first part deals with the principles of noise
control treatments using perforated metals; the second
part deals with typical applications. Readers who want
more technical detail will find it in the Appendices.
 Appendix D also includes worksheets that may be
photocopied, filled out and included in the job files for
individual projects.

16. APPLICATIONS
 1} Green environmental protection
 2} The light quality is hing and strong
 3} The watertight ness bears tide
 4} Absorb the voice declines
 5} Assortment new wave
 6} The specification is well-found

17. METHODS OF LAYING
 1} Exposed joist lifting method


18. HIDDEN JOIST LIFTING METHOD