and detailing suspended metal loth ond ploster ceilings

Technical Bulletin No.12:
Suspended Metal Lath and Plaster Ceilings
following technicol bulletin is a historicol orchive from
1958. lt is provided os o descriptive guide for informotion
and detailing suspended metal loth ond ploster ceilings
only. While the informotion contoined herein is relevont, it
should not be relied upon to be compliont with current
stondords for hongers; size ond spacing of main runners and cross
The
furring. For the most up to date information please refer to ASTM C 841Standard Specificotion for Installotion of lnterior Lathing ond Furring,
ond; ASTM C L063 Standard Specification for lnstollation of Lathing and
Furring to Receive lnterior and Exterior Portlond Cement-Based Plaster.
TECHNICAL BULLETIN No. l2
4
lll
o
z
SUSPENDED
METAT LATH qnd
PLASTER CEILINGS
6a
z
F
ul
to
Iz
-I
tll
F
=
o
lll
c,
=
Itl
ao
o
F
\--^----^-- ceilinqs of meral ldth and pla"ter are
LJUSPL,NDL,I-)
in the consruction industry for a variety
of purposes. Among the manv objectir-es accomplished
widel,v used
are:
Fire protecting the construction above
Concealing ventilating ducts, etc.
Reducing sound transmission
Enablins reduced floor slab thickness
Providing acoustical treatment
Beautilying interior oI the structure
Lowering ceiling to desired height
P€rmitting unusual lighting efiects
Giving a finished appearance
Any one of these reasons is sufficient to justify rhe
use of a metal lath and plaster suspended ceiling.
Very frequently, the desiguer accomplishes several of
the loregoing objectives rvirh one ceiling.
With versatility unlimited, metal lath and plaster
ceilings sometimes are perfectly level, sometimes are
domed, sometimes are formed into unusual contours.
Although always having contributed to the frre
protection of structural members,. the introduction
of lightweight aggregate plaster has created a greatly
broadened demand for metal lath ceilines. One inch
ol gvpsum-vermiculite or gypsurn.perlite-plaster over
rnetal lath forms a suspended reiling whi, h pror ides
rugged resistance to fire. A floor assembly with such
protection can qualify for ,I-hours or more fire resistance under the standard test procedure.
This nerv method rvhich we term metal lath and
plaster membrane fireproofing has contributed subsrantiallv to rhe lorvering of building costs. Savings
resulting lrom the marled reducrion in weighr are
discussed in more detail in Technical Bulletin No. 3.
In summary, probably no single construction as,
sembly serves more utilitarian purposes than does
a suspended ceiling of metal lath and plaster.
FINISHED }NEIAT LATH
SUSPENDED CEILINGS
AND
PLASTER
CONVOI.UIE SUSPENDED
OF METAL LATH CAN BE SHAPED TO MEIT
mot conplex conto.molions.
'w
Publlshed by
META IATH ITANUFACTURER!; ASSOCLANON
820 Tr3n.fal Road
St.Paul, l|N 5511'l
512.645.0208
THE
CEII,ING
2.0-
Metol Loth Celllng Suspended Below
sleel, Concrele, ond Wood Constructlon
I.O-
SIZE AND SPACING OF
AND CROSS FURRING
RUNNERS
Size and spa(ing of channels lor main runners shall confornl
lo Table ll, and su(h runners shall be .ross lulred hirh penril
rods or channels o[ the size and at the spacing required in
Table III. (lt is recommended that when main runners are
susp€nded from joists that they tun transverse ro the direcrion
of the joisrs.) Neither main nrnners nor cross fL|lring bhall be
let into nor come in contact with abutring masonr! or rein.
forced concrele walls or partitions. A main runner shall be
locared within 6" of the wall ro supporr rhe ends of the cross
furring, and hang€rs shall be located ro support rhe ends of rhe
When main runners are spliced, the ends shall be overlapped
less than 12" (with flanges of channels interlocked) and
securely tied near each end of the splice with two loops of No.
16 gage galvanized wir€.
not
/t.o-
AITACHMENT OF CROSS FURRING
TO
R,UNNER5
The cross fuuing shall be securely saddle-tied to th€ main
runners by not less than No. 16 gage galvanized wire at each
crossing, or bv No. 9 gage wire hairpin clips or equivalent clips
or attactunents. When furring members are spliced, the ends
sha be overlapped not l€ss than 8" (with flanses of channels
inrFrlocked, al)d s.curely ried near each end ot the splice with
tso
loops
of No. Io gage Baivant.d wire.
3.0-
HANoER'
All wire hangers shall
be of such lengrh that the lower ends
oI hangers may be saddle-tied or wrapped around the runnen
so as to pr:event tuming or twisting of the runners and to
develop the full strength of the han8ers.
All wire hangers shall be galvanized and shall be nor less than
Type I as set forlh in Eederal Specificarion QQ-W-401b, Wjre,
Steel (Carbon). Bare and Coated.
(NOTE: Insert here applicable supplernentary specifications for
type of construction involvcd.)
srEE[
Size end spacing of hangers for Mekl Larh ceilings susp€nded from steel construction shall be as
provided
in Table I.
For steel beams, joists or orher s[eel construc[ion,
hangers shall be wrapped around, ins€rred through,
or clipped or bohed to steel structural supports, so
as to develop the full stren8th of the hangers. All
wire hangers shall be of ample length such thar
the lower end o[ haneers mav be saddle.tied or
wrapped around the rinners sir as to develop the
full strength of the hangers.
5.O- CONCRETE SIAB
Size and specing of hangers for Metal Lath ceilings suspended from concrere flar slab consrruction
shall be as Drovided in Table I.
Haneers shall be secured !o steel reinforcement
in conirere with cinder
aggregare
and may be
se.
cured ro sreel reinforcemenr or looped or embedded
6.0-
coNcREtE
in^ron.rete with orher types.of .aggregares.
spe(ial insel!5. ar lfast equivalenr in strengrh to
the hangers, to which the hanqers can larer 6e at.
rached. may be inserred througi or a ached to rhe
lop of the forms in lieu of a;choring rhe hangers
drr€atlv rn th€ conarete.
JOTST
Size ot hanters lor lfrral Lath ceilirlgs suspended
(rom concrerE ioisr ronsrru(rion shali be is provided in Table l.
Hangers shall be inserred rhrough the cenrering
at the bottom ot ioists, and shall be Drovided wirh
a loop or other di:formation to positi'vely enter the
concrete, or be secured to the reinforcins steel.
Ir 20" wide form constructior,
hang€rs shall bc
In 30" wide
form construction, hangers shall be placed in each
row ofjoists.
Other approved attachments or inserts may be used
if of equivalcnt strength.
placed in alternate rows of concrete joists.
7.o- wooD
Size and spacing of hangers for Melal Lath ceilings suspended from wood consrrucrion shall be as
provided in Table l.
Wire hanqers shall be inserted in holes drilled
a rninimum;f 3" above borrom of joisrs and wirh
the upper end of the hanger in each case lwisted
three times around itsflf, or
Wire hangers shall be atrarhed lo 30d nails,
dliven on a downward slant inro sidrs of
ioisrs
which are sufficientlv ride ro Dermit not less than
3 inches Denetration into the rvbod. Snch nails shall
be driven at least 5" from bottom edges and nor
over 36" on cent€rs, with the upper end of rhe
hanqer in each case twisted three aimes around
itsell, or
four l%" No. 9 gage wire staples shali be used
to secure wire hangers to the side of joists. Staples
shall be driven tiorizontally or on a downwird
slanr. three near (he upper end of the loop and rhe
fourth to fasten the looie end, or
When purlins exceed spacinqs of 4' o-c.. 1t/".
No. O scriw eyes shall be fistenid inro heavv w6ria
flooring at not orer 3'o.c. so rhal rhey wil) sirpporr
an area not over I square feet with upper eird of
hanger to be inserted-in screw eye and ii each case
twisted three times around itself. (This spacing is
determined on resisrance ro wirhdrarval of rhe N;_ o
screw eye in Northern While pine. \Vhen wood
ofiering greater resistance is used, rhe spacing may
be slighlly increared or a smaller size s(rew fve
would be permirred. Exanple: A No. 4 screw eie
in Douglai Fir has equivaienl resisran(e ro withdrawal to a No. O in Norrhern While tine. or
Flat hangers, if used. shall be spiked ro sider of
joists with two l2d nails driven rhrorrqh hotes
drilled in rhe hanger and clinched ar teasi3 inches
above bottom
of
ioists.
8.0-
TYPES OF MEIAT I.ATH AND
ATTACHMENT TO FURRING
,,,Metal.Lath, of one of rhe rypes and weights lisre(l in Table
lV fur the rol'e,ponding spacing ol turrin-g. .hrll br ]rra(he.t
ro the Iurrng member. wirh rhi lonq dim;n.ion ot rhe sheer
across
t^*r I
-{r: rxo rrac$G o} riafloart
the furring, anct shall be caried down 6,, on ro the
walls and partitions, or Cornerile shail be useci.
Metal Lath shall be atrached ro rhe sreel furrins members
by No. t8 gage galvanized annealed wire ties space<i at not to
ex.cFii C" inrer\ale. lie. \lratt be t,t ed where .r,te, ot .l,.cl.
Idp al supporrs and a(,ide hpr ol .heer. bel$een \uppofls.
Diamond Mesh Metal Lrrh shall be lapped nor te* i6an r:,
at .ides: Rib Melal Larh shall be tappi<J ar ,i,tes hr nesrins
ouriide rib\ or.elvrge..{ll Ve(al Lalh shrll tap t" ar end,.
Fnd lrp. nf .heer\ .hould generallt or. ur onli orer .upporrs:
if between. end\ ol sheers ahall he la(ed or ;deouareir' ried
rogrrher wirh No. l8 gage gal\ani/ell anneateLl tie wire.
rigid hong.rs
Toblo lV
M.rol lolh
\
ty2.
Cro33 furring
|
175 tht.
loblolll\
Note
9.0-
IUPPTEMENTAI INSTATI.ATION PROVISIONS
9.1-P.ot .iion of hongcrr.
Rod and flat iangers may be ordinary unpainred mild steel,
except where ther€ is excessive moisrur€ oi couosive fum€s,
all rod and :flar hangers shall be coared wirh rus!.inhibitive
paint. Painting also is recommended for rheaten and audi,
roriums, and large
in publi( buitdings.
'eilinB.
In Concrere Joisr Constiucrioir.
l/,I" round niild sreet hanqers
may be plared 48" on renter in alrernare rorv. o{,onciete
ioisrs in 20" wide form construcrion.
:
-Where hangers are spaced not lo exceed 24,' on centers
along.ea(b runner or carrying (bannel, cross furring channels
ma) be omirted and larh ariached crosswise and direcrlv ro
runner channels; provided, however, rhar spacing cenaei to
center of such runner channels shall no! exceed- the limits
specified in Table IV.
(1) This spacing for furr€d ceitings under concrete joist con-
rAA;
$zt Ara! t|^ct o oa'Bcto3t fum|rtc
9.2-A[o.hm.nr ot flgr hong.r. ro mcin runn.r kalryin9) .hann.t..
Lower ends of flar steel hange$ shall'have holes Dunched
at lhe proper disrance \bul no( clorer tl.an r"" trorir endsr
ro which rhe runner channel shall be bolred wirh nor le\\
than 3s" diameter bolts. pro\ided thar tor (eilinq\ orer audi.
roriums, rhearers and other public buildings aid elrewhere
where an added factor o[ sateiy is de,irable,-rhe loser end ol
8ar steel hangerc shall be long enough to bend up sharpll
as stirrups under runner rhannel ro which rhey shall be bolied
as already described. and shall ronrinue up and be securelv
tied to-main portion of hanger not less rhan 6,, above runnei,
Sir., Typ. ond W6i9ht
(If live loads or addi(ional dead loads are conremDlared.
hanger and channel sizes, and melhod of a(tachmenr m:usr be
designed accordingly.)
9.3-H.nEorr to r..i.t <omFr.$ion.
In regions subject to tornadoes or cyclones, whcre uDwar(l
prejsures are likely ro be exened or wirere srrspentled ieitine
areas are exposed ro high winds rhro gh oul\ideopenines du;
ryt:g
a!
T^llr
tV
wHct|:3 0r narar ta$t at.o ,taorto
oi
ttrtar''
ing construcrion, hangefi shall eirhei be of a tipe ro" rerisr
or strurs o[ %,' channe]s or rees qol heavier size
where hangers exc€ed 4' o.c.) may be used. there slrurs shall
be used ve i(aily berween runnei (hannels and rbe (onsrruction above. being spacrd nor (o exceed 8, o.r. in borh direc.
compre-ssion.
tions. They shall be
in addilion ro rhe regular
hangers.
9,,1-V.nriloring,
\yhere larh and plasler (eilings are Io(ared under roof (onslru(lron. lr ls recommended rhat rhe space thus eslabiished
be v€ntilared. Such ventilarion shall be d;signed in accordance
accepred engineering practice.
with
NOTE: Weighti ore exclu3ive of poper, Sber, or orher bo.king.
STEE! PUR.tI
Sl..l roof de.k .oyorcd
wirh
in,0lotion
o.d
builr-up
rooflng
Stru.lurol
Chonn.l
Suspended ceiling is attached ro channel purlins,
by galvanized wire hangers inserted through shop-
cRoss
punched holes. (Instead of inserting through the
punched hole, the wire hanger may be wrapped completely around the purlin.)
SECTION
THRU PURTIN
l7
ELEVATION OF
Ih
I tsl'
| /\-
PURLIN AND
"bort
CEITING SECTION
x tL
srcct nor"nild
H#
wooD Jor5r
ioi3'3. Spocins ond
lVz' *itc
rloplct
Detail illustrates tll'o methods for attaching wire
hangers to wood joists for supporting a suspended
ceiling oI metal lath and plaster.
For nominal width joists of 2" or more, hangers
can be inserted through holes drilled in joists, or
can be stapled to their sides.
No. 9 gogo
Soddl!-ti. hangor
typ. of
lclh
[{.lol lalh
rpocinq
DETAIL
THRU
DOtflE CEil.tNG
AIL
PARATLEL
v
De$ription,
The use of ceilinq domes with or rcithout indirect
lighting fixtures isbne of the easiest and yet most
effective uays to achieve architectural distinction for
an otne|rvrse very orqrnary aPPealrng room.
Ellipses and citcular arcs are the usual cross-sectional shapes, but dropped centers or doughnutrlral,ctl str rrctrrres are also popular.
Latlrirrg 1.,ro,edure lor'dorries gerrerally lollows
specihcatiorrs for suspcndeti ceilings lor ceiling domes
rlith
It
,"
tliamcters of 8leet or more, flaln runners are
r lrlrrrrt ls lrert irrto (orr entric cirr les of gradu-
ate(l ili.rIllrtrl\ s.r tltrr the Itorirorrtal disra cc be
tweerr runncrs is not note tha:n 4'-0'/.
Harrgers can be t.-o. 9 gage galvanized annealed
wire, or:l/16" or ll" round mild steel rods, or l" x
3/16" tlat nrild stcel straDs. Thev are fastened to rhe
circular r trnrcrs ar spacirigs not io exceed 3'-0" meas11e(l al,)lrg tlre rurve or rlr. Irr rro tase js it permissible lor a No. 9 gage hanger to support rnore than
12.5 sq. [1. of ceiling.
Cross-Iurring menlbers are usually 31" channels
lrlared uith the 3;" dimcn\ion horizortal and rhe
0angcs irr a vertiral position \o tlrat the charrrrel can
be nrorc easily bent or sprung into the shape of the
dome. Thev are saddle-tied to the circular runlrers
like the radiating spokes of a rlheel, and the grearesr
spar l)ctr|een cltarrnels is restricted to 16".
Pencil rods and steel straps are occasionally used
for cross-frrrrins but the distance benveen circular
nrnners trust tlien be reduced to 2 ft. or less.
To cornplete the lathing, metal lath u'eighing 3.4
lb. per sq. yd. is tied to the cross furring members at
6" intervali rvith l8 gage tie rvire.
APRIL ]958
'
furring
PtAN
1% " chonnel
bote n.9
SECTION
Vt'donnol
TECHNICAt BUttETIN No. l2
SUPPTEMENT NUMBER
SUSPENDED AAETAT tATH
ond PTASTER CEItINGS
O CHANNEL CLEARANCES
O COMPRESSION MEMBERS
O TIES AND SPLICES
O VENTITATION
Wh.rc lorh ond plor-
tor <oilingr or. lo€ot.d undcr rool
conrtruclion,
I
it ir r.c-
omm.nd.d
iho r
lhc rpoc. thur .rtob-
lirh.d b. v.ntilorod.
Such v.ntildiion ,holl
b. d.'isn.d
nc.
ac<o.do
in
w
ilh
oc.cprcd cngin..r;ng
4
ul
o
zao
zts
RUNNER
VENTITATION
AND FURRING CHANNEL
CTEARANCES
t.o
u
zI
IIt
of No. 16 sos. wir.
croei lurring
8" lnin. tor .ro3r fufrins
=
o
ua
F
I
gl
CHANNEI. SPTICES
SADDLE TIES
TIES AND SPLICES
z
gr
ao
o
Compre3.ion
fi.hb€rt
IO REsIsT COMPRE'SION.In resiohr subiect to rornodoes
or cyclones. where uPwo.d Pre$ures
HANGERS
ore likely ro be.xerled or wher.
surpended ceiling
pored io high wind3 rh.ough oul'
3ide openingr during con5lru.iion,
hongers sholl either be of o lype
ro .esist <ompre5!ion, or nrutr of
3/.' <honnelr o. teer (of heovier
,ize where honger! exceed 1'o.c.)
hoy be used. These 3rrurr 5holl be
used verii.dlly belween runner
.ionnel3
ond the conslrqciion
obove, heing 3poced nol
1o ex.eed
8' o.<. in bolh directionr.
Cror3
furring
They
,holl be in oddirion to the regulo.
COMPRESSION MEMBERS
MEIAT LATH MANUFACTURERS ASSOCIATION
ENGINEE
R
5 BUIIDINS
ctEvt tANo r4, oHro
MAXIMUM SPACING OF WIRE HANGERS
AI,ONG
MINIMUM SIZE OF HANGERS
EACH
MAIN
RUNNER
No.7 goge golvonized *ire or %6 rod
No. 9 goge solvonired
*,e
o
SIZE Al{D
No.
o
o
l6 sdge golvo.ized
5"r
wire, !oddleried
,'z
SPACII{G FOR
(:)
lv|AII{ RU}|]{ERS
5Z
zA
cR0ss tuRRll{G
z
N<
;:
]YlTIAL LATl|'
-
-o
z z
z
F
o
z
q6
oE
F:
z(J
I
a.
.9
>n
4 4
f
4
=
z
=
a
z
UNDERSIDE OF
SUSPENDED
SPACING
CEILING
oF cRoss
FURRING (3}
(l)
Fo. voriolioir ree boric toblet in le.hnicol Eulletin No. 12.
(2) fo. concrele coshu<rion only.
(3) Sporing of dos.f,rrri6s must nol .tceed norinum ollowoblo
rpon for iype of metol lorh u!ed.
N O VEM
BER, I960
IXDXD
ffi
5a
TECHNICAt BUttETIN No. I2
SUPPTEMENT NUMBER
SUSPENDED METAL TATH
ONd PIASTER CEILINGS
2
OMAXIMUM SPANS FOR MAIN RUNNERS,
FURRING CHANNELS ond METAL LATH
.PROPERTIES OF CHANNETS AND HANGER DATA
MAXIMUM
MAXIMUM CENTER TO
B
2'-6"
INFORI
Itl
o
z
o
l
u
2
T
(J
F
r40
t.
o
-
.o
\Jz
z9
20
(3)
DI
RUNNERS FOR THE5E
150
175
1\2
214
211
211
90
t24
lt3
uPr
fN
238
120
158
238
I
CROSS IURRING
| /t0
| ,10
140
70
88
105
123
r60
t60
160
r60
(3)
{l)
180
238
10s
120
o
x
=
z
t86
186
186
186
!o^
63
75
88
lo0
221
40
50
60
8l
8l
8t
221
See Technicol Eulletin No. 12, Toble
lood of
lishiweight dggregoie.
Lower number indicoies colculoted corYing copocitY
of runner, in poundr, limited by (W) momenl
(31 Nol recommended.
(4) 8d3ed on coid-rolled chonnels fobricoled by members of l'\elol
Loth Mon'Jf octurer5 Aito.iolion.
'| V1" C, R.
CHANNET
in sulpended ceilinss.
@ 175 lbs.
per 1000 fest (,{)
"X" Below Indicotes Weight ond Type
{per Sq. Yd.) of Recommended Melol
224
(3)
/
/{
CHANN€I
@ 300 lbr.
/**
R
9
2,.o,
I
eZ
'/."
I
3'-O"
{3}
/."
P.n.R.
Y."
c.R.
Chonnel
3/1" c.R.
Chonnel
Y."
Pen.R.
1/t" c.e.
3/." c.P.
3L"C.P..Ch.
/."
C.R.
B
CENTER SPAN
?.n il Y." P.6.i
1/"C.R.Ch,
l:-
MAX|MUTI CENTET TO
2'-6'
Chonnel
14"
C.R.
Chdn.el
./."
c.R.
number denore3 e"imoted weiehr or merol
loth ond plo'ter <eiling, in Pounds, boted on o deod
lO pounds per sq. ft. No vdrionce should be mode for
lzt l-----l-'+upp.r
311" C.e.
(3)
3'-6"
{31
1/1" c.P..
'4"
c.9..
l3)
ll for mai. runnercPons sen-
{5) Morimum rpon "C" of 3.4 lb. diomond mesh merol loth is 13/r"
90
65
CHANNEL
@ 59O lb,.
per | 0O0 feet (4)
(3)
75
65
C.R.
268
60
C\
2"
60
a.
ro
NOTES
(3)
'|
100
l
RUNNERS
(3)
I
=
@
RECOMMENDED
REQ UEST
80
.o
RUNNERS(r)
sP/ \NS AV/ \ITABTE
135
121
MAtN
I
RECOMMENDE
125
.o
Ui
(3)
I
r00
Uz
Y.z
4,.o,,
179
2e.
cO
3'-6"
150
|
179 |
>ut
p=
|
t*_l
120
z
^-d
-'z
dz
4
o
r!
c
^ATroN
D|NG
REGAR
F
=
B
CENTER SPACING
2',-O"
4
SPANS FOR
1'-O'
{3)
3/t"
c.P.
{3)
{31
,l
le
/e
-.o
*-'
Loih
/8
/**
to
ot/
3l €l
6
+"*/
EtEMENTS OF COLD-ROILED CHANNEL5 (ol
FABRICATED
BY
MEMBERS OF METAI- LATH
MANUFACTURERS ASSOCIATION
NOTE
(o)
Properties S ond I ore comprrted dboul lhe slrongest (X-X) oxis of the chonnel.
TYPE OF
HANGER
SAFE LOAD
lN
POUNDS (o)
ESTIMATED
ULTIMATE
STRENGTH(b)
MAX.
AREA
SUPPORTED
PER HANGER(c)
Round Rod
Flot
12.5
17.5
NOTES
o design or working
(o)
Rod ond flot hongers ore bosed on
working slress of 18,000 P.s.i.
(b)
(c)
Bosed on ultimole strength of 60,000 p.s.i. of gross oreo.
stress
of 20,000 p.s.i. Wire hongers ore bosed on o
Mulriply individuol figures by 10 lbs. per sq. ft. {overoge weight of ceiling) to deiermine the opproximote weight of ceiling
in oounds. Also,these oreos do nol utilize the full sofe lood of the honger, but ore bosed on spocingt generolly recognized
ond Used in suspended ceiling conslruction
(d) Arrived ot by deducting oreo oI 7/tt" diometer hole for 31" diometer boll.
(e) Sofe food on net oreo of flot is greoler fhon shown but sofe lood on 3/s " bolt in single sheor is.068
times l0 kips per sq. in.: 680 lbs.
({)
design or
sq. in. (root oreo)
Bosed on strengih o{ honger only. Welds hove nol been colculoted os iob requirements vory depending upon lood
supporled.
DECEMBER 1957
lo
be
IECHNICAL BUtLETIN No. l2
SUPPTEMENT NUMBER
SUSPENDED METAT TATH
ONd P[ASTER CEIIINGS
Forned 7r" chonnel brockers,
13
O
%' o.
TIGHTING DETAITS
c. mox.
Anoch by shoe ond wke lies
Trolsh (hoy or moy nor be
ploirered on 0pper ridel
4,
ul
o
zao
F
=
f
@
Y.'
Chonnel
9
2
I
t
;;--\
A.- \
;:.T*' AVf*\-:J
z
o
c,
=
ao
o
F
rurrno3e /
loPrionol)
/ \--ll{--E
/
L
ll H ,c'G3{uring
Fq.
!
{wid" flot,wire-iied to
q
c.osr fu.rins
%" dio. rod, wire-tied to not3
TIGHT IROUGHS.
IN A SUSPENDED METAL IATH AND PIAsIER
CEITING
Metol lsth ond plo3ler ceilins
(surpended. furred or conrocl)
Wire supporr ottoched ro
mefol rlud (if needed)
These illustrolions show only o few of fhe vorious
monners in which troughs for indirect lighting
con be conslructed. Either 3/c",1Yz" or 2' coldrolled chonnels moy be used for froming.
be lothed ond plosfered on the
upper side if desired. lf o continuous refleclor
is used with d continuous ffxture, plostering in
the trough moy be omitled ond the ffxlure con
Troughs moy
resi on lhe chonnels.
7a" chonoel brocket welded
or wire-tied to mehl nud
f
LIGHT TROUGH ATTACHED TO WAtt
PARAI.TET WITH
RUNNERS
PARAILET WITH
MAIN
CROSS FURRING
REFTECTED CEITING PIANS
WITH TROFFER OPENINGS
sEcTioN "A-A"
sEcTtoN "s-8"
I.IGHTING IN CEIIINGSTROFFER
AND
FI.USH
of fixlures ond lheir ottochment in o suspended ceiling ore nol
limiied to the deloils shown.
The lypes
Other lypes
of lroffers moy be
ol-
toched to the ceiling in o monner sim-
ilor lo those illusiroted, or moy
be
suspended from the overheod conslruclion, ond instolled 5ingly or in rows.
Other styles of recessed lights olso ore
Metol
ldth
ovoiloble.
Ploner
TYPICAT SECTION THROUGH TIGHT TROFFER
IN MEMBRANE FIREPROOFING
DECEMBER
I959