Light Gauge Steel Truses Guide

8/2/2019 Light Gauge Steel Truses Guide

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Course SponsorAEGIS Metal Framing

14515 N Outer 40 DriveSuite110

Chesterfield, MO 63017

Light Gauge Steel Trusses

314-851-2234

E-mailjaltman@aegismeta lframing .com

The Specification, Design Manufacturing and

Webwww.aegismetalframing.com

Course Numb er

Please note: you will need to c omplete the c onc lusion quiz online atronblank.com to rece ive credit

An AIA Continuing Educ a tion ProgramCred it fo r this course is 1 AIA/ CES HSW Learning Unit


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Please note: you will need to complete the conc lusion quiz online a tron an .c om o rec e ve c re

This p rog ra m is reg istered w ith the AIA/ CES for c ontinuing p rofessiona l

ed uca tion. As such, it d oes not include c ontent that m ay b e d eem ed or

c onstrue to e a n a pp rova o e n orsem ent y t e or on a n

Associates, Inc. of any material of construction or any method or manner

of ha nd ling , using , distrib uting , or de a ling in a ny m a te ria l or prod uc t.


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Co ri ht Materia ls

s p resen a on s p ro ec e y . . an n erna ona c opyr glaws. Reproduc tion, distribution, d isp lay and use of the

presenta tion without written permission of , .and

AEGIS Metal Framing 2009.


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Learnin Ob ectives

pon omp e on o s c ourse e es g n ro ess o na w eable to:

Solution

Exp la in a pp lic a tions for Proprieta ry LGST

Spec ify LGST Desc ribe the design proc ess for Fac tory-built LGST , , ,

Fac to ry-built LGST

Compare and c ontrast a n LGST p roposa ls and exp la in whatma kes a c om lete truss s stem


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Wh Li ht Gau e Steel Trusses?

erever s eep sope , res en a -s y eroofs a re desired

Non-c ombustib ility is manda ted

The IDEAL solution is...


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Li ht Gau e Steel Trusses


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The Advanta es

1. 100% non-combustible2. Lon c lea r-s an ca ab ilities

A. LGSTs c an typ ic a lly span 80+ feet, depend ing on load ingcriteria.

B. Obviously, spans will va ry grea tly between snowy reg ions suc h

as New Eng land and warmer c lima tes like Texas.3. Limitless roof and c eiling p rofiles--just like wood trussesA. Eng ineers ha te to hear this, but w ith the c omputer software

availab le today, designs c an be more d ynamic than ever.4. Lightweight

A. LGSTs a re typ ic a lly ha lf the weight of wood trusses due to the irg strengt to we g t ra t o.

B. This is an advantage for long spans and heavy conc entra tedloads sinc e the trusses are not ha ving to work doub le duty to

sup por emse ves a s we a s e oa s e ng a pp e .


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The Advanta es

- -. A. Proprieta ry trusses are designed by experts, and sea led by

veterans in the light gaug e truss business.

A. Often sp rinklers c an be d ownsized or even elimina ted whenthe roof struc ture is built from c ompletely non-c ombustib lemateria ls. There is nothin to burn!

7. Compatib le w ith a lmost any dec king / roofing systemA. There a re fastening methods tha t c an effec tively hand le

c onnec tions to everything from p lywood and meta l dec k tounique mate ria ls like Struc tural Insula ted Pane ls or SIPs.

8. Relieves design firms of costly, time c onsuming roof design work--frees them up for more p roduc tive endea vorsA. Bec ause the design software hand les the eng ineering , sizing

of materia ls and c a lc ula tion of loads, a rc hitec ts andeng ineers c an simp ly spec ify tha t LGSTs be used, p rovide the

asc esgn c r te ra an pro es. e truss esgner can ta eit from there.


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LGST a re an idea l substitute for

Bar Joists

Red IronConcrete

Fire

Wood


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Almost an Confi ura tion is Possib le

Radius forms

Bow string trusses

Sc issor trusses

Almost any Configuration is Possible


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The LGST Marketp lac e


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The Market Toda - Commercial/Institutional

n o ay s mar e , e es p ro ec s o a e a van age oLGSTs are c ommerc ia l and institutiona l p rojec ts. These a re

typ ic a lly la rge p rojec ts in d iverse market segments.,to d ra in from the roof a rea and red uc ing the c hanc e for lea ks.

Tighter c ode enforc ements a re requiring tha t more a nd more- .

LGSTs are popular in high g rowth segments, areas tha t a resee ing la rger than normal c onstruc tion g rowth.

years, and C-stud trusses ha ve been used for 30+ years, they

are still c onsidered Up and Coming in the d esign community.Certain markets have b e un to emb rac e the fea tures andbenefits of LGSTs. Others still view them as new or do no t knowabout them a t a ll. There is still a lot of ed uc a tion to be done.


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Applications


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A lic a tions

There a re many typ es of struc tures tha t a re ana tura l fit w ith LGSTs

We will look a t a few of the most c ommonapplications


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Assisted Livin

These struc tures a re a growingmarket as our popula tionages. The c ombina tion of

noncombustible structuresand the desire for a Residentia l Look bode wellfor LGSTs.


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Educational

sc hools as well as dorms anduniversity b uild ing s a ll p resent

roo fs that need non-combustible structures. In

,

c overing over fla t roofs of 30yea r old sc hools a re a grea to t ion that save lots ofmoney for sc hool budgets.We will look a t a c ase stud yfurther into the c ourse tha tillustra tes the opportunities forold sc hool roofs to bec hanged d rama tic a lly.


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Offices

Offic e c onstruc tion is another growing opportunity for LGSTs. Ag a in,c odes require non-c ombustib le c onstruc tion. In add ition, in somearea s c odes require offic e build ings to c omp lement the surround ing

arc hitec tura l landsc ape, whic h may reflec t residentia l design.


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Correctional

n ortunate or soc ety,but g ood for business,

Correc tiona l Fac ilitiesa re a no er grow ngsegment for LGSTs.


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Banks/Financial

oney s a r enoug o eep w ou go ng up n ames

Non c ombustib le materia ls a re a must for fina nc ia l institut ions.

Some U.S. suburban b anks tend to have more of a residentia llook as well.


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S orts/ Rec rea tiona l

e nc rease o newstadiums for professional

teams as well as the new

sports c omplexes, thissegment is a lso growing .


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Li ht Industria l

op portunity to app ly the look

of residentia l roofs towarehouse fronts and offic espac es that a re p a rt ofwarehouses.


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Hos ita lit

esp e e ups an owns o e mar e , osp a y s oua lways be a growing and c ha ng ing industry. LGSTs provide

grea t solutions for two build ing methods; as the c omp lete roof

handling a nd o ther mec hanic a l devic es p lac ed on the roo f.


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Retail/Mansards

When residential c onstruc tion goes on the rise, strip shopp ing c enter

c onstruc tion often follows. LGSTs are often used to frame out thesestruc tures.


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Other Build in T es Ma Inc lude

ea ers Military Housing

Sta d iums Water Trea tment Fac ilities

Fire Stations Libraries an so on.


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Case Stud ies


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Case 1

ro ec - urs ng ome o un ce,Eunic e, LA

, sq . . asss e v ng ac y Light gauge framing spec ified for

non-combustibility ,

stic k framed with studs LGST fab ric a tor designed and

, By utilizing pre-fabric a ted trusses, the

c ontrac tor estima ted they saved 24-framing . There were a lot of savingsrea lized , not to mention the b ene fitsin sc hedulin !


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Case 2

ro ec - a ar e ss . v ng,

Livonia, MI

Five build ing s to ta ling 35,000 ft2

20 yea r old Fire reta rdant wood rooftrussesa nd p lywood dec king litera llyfalling apart--trusses breaking, sagging,

dec king c rumb ling Insurance c ompany req uired c omp lete

rep a cemen an or c over ng o ex s ngroof

LGST fab ric a tor stepped in with severa l

The utility b uild ing trusses and dec k wereto rn o ff in sec tions and Ultra-Span trusses

.

and were a ttac hed to steel trusses


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Case 2

The four residentia l units p rovedto be more c ha lleng ing. Themec hanic a l and elec tric a l

systems were running THROUGH Light gaug e sc issors trusses

were designed to fit ove r theexistin roof and take over

t e truss system n or er orthe wood trusses to be pulled ,a ll the mec hanic a ls would

the loa d handlingresponsibilities. Light gaugetrusses were p lac ed over the

ave o e pu e an e

residents reloc a ted during theentire p roc ess

top of the old truss system,elimina ting the need to (1)

remove the mec hanic a l andelec tric a l systems, and (2) theresidents were ab le to rema inin their homes, elimina ting a

ot o stress a n expense oreveryone!


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Case 3

ro ec - owar . nn s c oo

30+ yea r old fla t roof leaking like a

Add itiona lly, sc hoo l boa rd wantedto c onc ea l new roo ftop AC units

built-in mec hanic a l spac e Sing le row of stub c olumns insta lled

Roof penetra tions red uc ed fromhund reds to only 50

Entire re-roo f c om leted in twoweeks with no c lass interrup tion


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Truss Systems

C iti l El t f C h i


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Critic a l Elements of a Comprehensivepec c a on

s a re g y eng neere u ng c omponen s. ouproper design, qua lity c ontrol, and p rec autions, serious p rob lemsc an arise. In order to ensure tha t a qua lity produc t is p rovided ,

- .

The following examp les illustra te the d ifferenc e between fac tory. .

method would you p refer for your p rojec t?


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Whic h is More Prec ise?

.

Versus This!

C iti l El t f C h i


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Critic a l Elements of a Comprehensivepec c a on

n a on o e ng ac ory- u , c omp e e eng neer ngand tec hnic a l sup port is a must. All truss-to-truss, truss-to-

bearing c onnec tions, and system b rac ing spec ific a tionsmust be p rovided by the truss supp lier. Inc lud ing spec s for100% mill c ertified steel and UL c lassific a tions whenre uired . These elements a re c ritic a l. The must be

spec ified and enforc ed or someone w ill likely attemptshortcuts.


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Cost Effec tive LGST Assemblies

Another benefit to spec ifyingLGST from a proprieta ry sup p lieris the ava ilab ility o f UL ra tedtruss assemb lies. Assemb lies

from proprieta ry sup p liers a reab le to ac hieve 1-2 hour ra tingsw on y one a yer o gyp sum,c ompared to wood truss

assemblies tha t must use two.


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T ic a l Commerc ia l Assembl

our + w on y onelayer of Type C p itc hedtruss with insula tion on

sys ems a re a e oac hieve the UL ra tingswhile ma inta ining the

5

6

p rac tic e o f 48 inc hes oncenter.

3

4

1

7 8


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Design of Fac tory-built LGST


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Desi nin Fac tor -built LGST

oug propr e ary russ sys ems are a new me orela tive to other framing systems like red iron and bar joist,

they are modeled a fter the wood truss industry, a strongforty-yea r history with a p roven trac k rec ord of qua lity andc ost effec tiveness. Tha t trad ition, c ombined with best ofb reed desi n softwa re, ma kes for a ver owerful tool.

Truss design software a llows fabric a to rs to design w ithspeed , ag ility, and a c c urac y. Mod ific a tions c an be

budgets and fine tuned estima tes. CAM andmanagement tools a re a lso a rea lity with truss design

.


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Sta te-of-the-a rt Design Software


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SoftwareSoftware

There are three ma in steps to designing

Design, and Cost Estima ting. Mostp roprieta ry systems p rovide these threeelements to the truss fab ric a tor. It is the

job of the fa bric a tor to inp ut thebuild ing information into the softwa re.

D i i F b il LGST


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Desi nin Fac tor -built LGST

e o ow ng proc ess s yp c a or pu c y russ wor :

Onc e the b id for trusses is awarded , eng ineering d rawings are

- ,d rawings are reviewed and sea led . Connec tions, b rac ing, andother spec ia l servic es may a lso b e requested . At tha t point, the

,

(typ ic a lly multip le c op ies), in less than 48 hours. Sub mitta ls a rethen made to the a rc hitec t, c ontrac tor, and projec t engineer

.


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Parameters Effec ting LGST Cost

D i F t I t i T C t


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Desi n Fea tures Im ac tin Truss Cost

Roof p itc h and heel height a re two o f theTruss Cost vs. Span

6" Heel Height, Variable Roof Pitch

most c ritic a l elements that c an effec t thec ost of a truss system. Based on these

graphs whic h have been d evelop ed over5.506.50

7.50

8.50

s

t,$persqft

2:12

3:12

a period of severa l yea rs, you c an seetha t a s span inc reases, steeper slopes a reab le to keep the c osts lower. Also,

1.50

2.50

3.50

4.50

TrussMaterialC 4:12

5:12

6:12

nc rea sng e ee e g a ows or a

more effic ient and therefore more c osteffec tive d esign.

20 30 40 50 60 70

Span, ft

Truss Cost vs. Span

10" Hee l Height , Variable Roof Pitch

5.005.50

ft

2.50

3.00

3.50

4.00

4.50

ssCost,$persq 2:12

3:12

4:12

5:12

1.50

2.00

20 30 40 50 60 70

Span, f t

Tru

D i F t I t i T C t


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Regard ing truss spac ing in most c ases,Truss Cost vs. Spacing"

nc truss spa c ng s t e most c osteffec tive, espec ia lly when designingtruss systems with slopes less than 3 on

, ,

3.50

4.00

e

rsq

ft

2:12

. e eng o over ang c an a sop lay a role in the c ost of the trusssystem. As overha ngs reac h 3 feet,2.00

2.50

3.00

Truss

Cost,$

4:12

5:12

6:12

dramatically.

.

2 4 6

Truss Spacing, f t

Truss Cost vs. Overhang Size

Variable Pitch 10" Heel 20 ft S an

4.20

4.60

5.00

5.40

per

sqft

2:12

3:12

1

1.80

2.20

2.60

3.00

3.40

.

TrussCost,$

4:12

5:12

6:12

.

0 1 2 3 4 5

Overhang Length, f t



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Concerning the d ebate of Truss Cost vs. SpanVariable Pitch, No Interior Bearings

w e er or no o a n ernabea rings, one c an see that thec ost of ad d ing one bea ring

c an more than a for itself5.00

5.50

6.00

e

rsq

ft

2:12

c omparing the overa ll c ost ofthe truss system. For instanc e, atruss with a c lea r span of 70 3.00

3.50

4.00

4.50

TrussCost,$

4:12

5:12

6:12

c ost approximately $4.60.

2.50

50 60 70

Span, ft

Truss Cost vs. Span

Variable Pitch One Interior Bearin

2.70

2.90

3.10

3.30

ersqft

2:12

By add ing one interna lbea ring, the c ost of the

same truss d rops to less tha n

1.70

1.90

2.10

2.30

2.50

Truss

Cost,$p

4:12

5:12

6:12

. .Just bec ause LGSTs c anspan 80+ feet, it isn t a lwaysthe b est op tion.

1.50

50 60 70

Span, ft



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Lon overha n s c a n a d dTruss Material Cost vs. Wind Speed

4:12 Pitch, 40 ft Span, No Overhang

sub sta ntia l costs, espec ia lly in highwind load zones. It is interesting to

note tha t in either c ase, the Ma in

4

4.5

r

sqft

Wind Forc e design method is lessc ostly tha n d esigning usingc omp onents and c ladd ing.2.5

3

3.5

TrussCost,$p

MWFRS

C&C

2

110 130 150

Wind Speed, mph

Truss Material Cost vs. Wind Speed

4:12 Pitch, 40 ft Span, 3 ft Overhang

5

5.5

6

6.5

t,$

persqft

3

3.5

4

4.5

ussMaterialCos

MWFRS

C&C

2

2.5

110 130 150

Wind Speed, mph

T



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little c hange to the overa ll design of the struc ture. Looking a tthis examp le, the truss on the left p rovides the same inte rior

slightly higher exterior slope. By add ing some spac e w ithin thetruss, loads are a b le to be d istributed muc h more effic iently. Thistruss a lso erforms muc h better, a llow in the build in muc h lessdeflec tion in a ll d irec tions.

Truss Cost = $583.00 Truss Cost = $748.00


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Environmenta l Benefits of LGST

L E E D Certific a tion with LGST


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L.E.E.D. Certific a tion with LGST

g gauge s ee russes a re exce en p ro uc s or use owar

ac hieving c ertific a tion through g reen build ing ra ting p rog rams

suc h a s LEED. Bec ause light gauge steel produc ts a re up to

100% rec yc led and rec yc lab le, they help to inc rea se the

c hanc e o f rec eiving Ma teria l and Resourc e Cred its. The

number and c a tegory of c red its tha t steel trusses helps in

c ontributing to varies dep end ing on the struc ture o f the ra ting

system being app lied . Another potentia l a rea of c ontribution

inc lude re iona l ma teria l rod uc tion and fab ric a tion in rela tion

to the jobsite depend ing on loc a tion. Other susta inab le

advanta ges c ould be rea lized through the use of steel trusses,

system expert.


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Fabrication

Fabric a tion Guidelines


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Fabric a tion Guidelines

Now we are o in to o into more de th about the advanta esof fac tory fab ric a ted LGSTs. Trusses c an be built and sta ged inc onjunc tion with the sc hedule of the rest of the p rojec t. Trusses

c an be d elivered in sta es as the are needed for erec tion.Fac tory built trusses c an be built to exac t d esign p arameters.Bec ause o f the fac tory setting , supervisors c an manage a ndc ontrol multip le p rojec ts within the fac tory, c ontrasted to anoc c asiona l jobsite visit to c hec k qua lity of work. In add ition, those

who are build ing trusses a re truly Truss Professiona ls. It s wha tthey do. They aren t build ing trusses one d ay and hanging d rywa llthe next. Jig assemblies a re utilized in fac tories to be sure tha t thelast truss in a run matc hes a ll other trusses in the same run. Qua lity

is further enha nc ed due to a c ontrolled environment. On theo s te , qua ty may s p as a resu t o e ements. o rtcutsmay be used when tempera tures d rop or when ra in sta rts to fa ll.There a re a lso servic es being developed tha t c an p rovide thirdpar y qua y gu e nes.

Assembl Methods for LGST


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Assembl Methods for LGST

Uni-Strut i s

Laser set-up

an ry a es


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Shipping

LGSTShi in Basic s


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LGST Shi in Basic s

.50 foot ma ximum leng th and 8 to 10 foot ma ximum w id thwithout permits and esc orts. Trusses up to 80 feet long and 20

feet ta ll ca n be shi ed with s ec ia l ac c ommoda tions.However, p iggy bac king & sp lit trusses are more c ommon.Some fabric a tors will ship vertic a lly with a low tra iler when

ossib le. Wood truss roll off tra ilers c an be used when trussesare adeq uately p rotec ted from da ma ge. Coord inationbetween fabric a tor and job site for p roper sequenc ing is vita l.

LGSTShi in Tec hni ues


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LGST Shi in Tec hni ues

These pho tos illustra tesevera l examples of trusses

shipped c orrec tly.


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Hoisting and Insta lla tion

Insta lla tion Fund amenta ls


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o s ng an ns a a on are c r c a e emen s o e suc cess oLGSTs. With p roper p rec autions ta ken, insta lla tion should besmoo th and uneventful.

Insta lla tion Fund amenta ls


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ne grea resourc e or e russind ustry is The Field Insta llationGuild for Cold-Formed Steel Roof

.ava ilab le through the LGSEA, ad ivision o f the Steel Framing

.

www.steelframingalliance.comIt is a grea t resourc e for manyelements of truss insta lla tion, suc has permanent truss b rac ing .

Hoistin


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ex o rac ng, s s per aps e ey o suc c ess u ns a a on.There a re so many wa ys to do it wrong, and only a c ouple ofways to do it right.

...

Hoistin


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THERIGHT

A spreaderbar and

n exper ence ns a er

Pre-assemblies


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Pre-assemblies a re a nother good op tion to c onsider whenp lanning the truss insta ll. Depend ing on ava ilab le spac e, thisop tion makes a lot of sense, a llowing workers to sta y c lose to the

groun ns ea o wor ng rom ve s o res up . nce e russesare erec ted , b rac ed and sometimes dec ked , the entire roof islifted (or flown) into p lac e. This a lso a llows c rane t ime to be

to save money.

A Grea t Idea for


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Tall build in s Unusua l site c ond itions Job sites with a mple spac e

When c rane time is c ostly When t ime is of the essenc e


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Comparing LGST Proposa ls

Com arin Pro osa ls


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ese var ous cons era ons can ecome very con usng w enthe truss c ustomer has to c ompare and c ontrast five to tend ifferent truss pac kages. Eac h truss sup p lier will p rovide d ifferent

p iec es of the pa c kage. Come b id d ay, it bec omes veryc hallenging to d etermine the b est pac kage d ea l.

Com arin Pro osa ls


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,proliferation in the number of truss fabricators

Barriers to entr a re low non-c ap ita l intensive limited rea l esta te requirements low skilled labor

n c er a n a reas, eng neers arc ec s s a ow ng o s e

fabrication Third party software ava ilab le for simp le truss ana lysis The result c an be multip le b ids on same projec t

A rec ent large p rojec t in TN attrac ted 12 truss b ids

Com arin Pro osa ls


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t so many potent a truss b idders, how is

Com arin Pro osa ls


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what elements make up a

c om lete truss s stem

are not c omparingapples to oranges

Com arin Pro osa ls


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c omp e e ys em mus nc u e...

Properly designed trusses

- - Truss-to-struc ture c onnec tions Insta lla tion b rac ing Let s look a t eac h item in more d eta il.


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Properly Designed Trusses

Pro erl Desi ned Trusses


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e r eac russ s esgne correc y, e sys em mus edesigned to work as a whole.

En ineerin DrawinEn ineerin DrawinJob Name

Number of plies

Job Name

Quantity of trusses

There are a lot of elements that go into a correc tly designed truss.

Truss ID


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Truss ID

TrussDimensions

Truss ID

TrussDimensions

Overall

truss

Number ofscrews requiredat each

connection

Trussslope

Indicateslateral web

bracelocations

Overalltrussheight

Trussslope

n ca eslateral web

bracelocations Number of

screws requiredat each

height

HeelTruss Loading

connec on

Heel

Height

HeightTruss LoadingDeflection

InformationTrussSpacing Applicable

FastenerValues

Truss weight

CombinedStress Index

Applicablecode

TrussSpacing

FastenerValuesSteel sections

Stress Index

Bracin Re uirements

e ect on n o

Steel sections

Bracing Requirements

Truss Reactions

Truss Reactions

Individual member

Individual memberforces


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Truss-to-Truss Connec tions

Truss-to-Trussonnec ons


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ese c onnec ons arec ritic a l to the p roperfunc tioning of the truss

Connec tions must sa felytransfer a ll loads into

They must resist up lift asnecessary

truss designer p rovide forthese connec tions

ANSI TPI 95If a LGST provider dec linesto provide these

,

ACCEPT THE PROPOSAL!


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Trust-to-Struc ture Connec tions


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Truss-to-Struc tureonnec ons


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These a re c ritic a l to the properfunc tioning of the truss system

Resisting uplift

nc ors russes o s ruc ure Designer must ac c ount for

bea ring surfac e, atta c hment,

conditions Standard deta ils useful, but

c ritic a l, espec ia lly in high windzones

engineer


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Truss Brac ing

The Card ina l Rules of Truss Brac in


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qua y mp or an o e russes emse ves s e russ rac ng,both insta lla tion and perma nent.

ALL truss systems require b rac ing --PERIOD!!

Fa ilure to adhere to Rule # 1 is the primary reasonfor truss

c ollapses (typ ic a lly during insta lla tion)

Rule #3 Disputing Rules # 1 and # 2 d isp lays an absence of

knowled e of how truss s stems func tion

The Card ina l Rules of Truss Brac in


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Resulta nts for NOTfollowing Rule # 2

Trusses tha t had

bracing

T es of Truss Brac in


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ns a a on rac ng Lac k of insta lla tion brac ing is the reason for virtua lly a ll

roof c ollapses during c onstruc tion

bracing

Provides for web brac ing , shear d iaphragm transfer,

and overa ll roof system sta b ility

Installation Bracin


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ns a a on rac ng s us as e name mp es, rac ng a eepsthe trusses in p lac e d uring insta lla tion. There a re three parts to it,top c hord b rac ing, bottom c hord brac ing, and web brac ing.

. ,used in ea c h loc a tion. It is sa id tha t without d iagona l b rac es, a llthe trusses simp ly fa ll the same d irec tion. Don t forget the

remain in the system and serve as permanent b rac ing.

Guidelines pub lished by LGSEA

Ground b rac ing Top c hord brac ing

Keeps c hords in line rac es c or s rom uc ng Bottom c hord b rac ing

Keeps c hords in line Web p lane b rac ing

Help sta b ilize the entire system p rior to dec king

Field Insta lla tion


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Guide for Cold -Formed Steel Trusses

The Field Insta lla tionGuide for Co ld -Formed

Steel Trusses, p rovidedby the Light Ga ugeSteel Eng ineersAssoc ia tion, goes into

grea t deta il about thebrac ing req uired forrusses.

Permanent Brac in


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ermanen rac ng s a w c rema ns n p ac e a er etrusses are e rec ted . This b rac ing is designed to keep the trussesin p lane a s loads a re a pp lied , p reventing the c hance for out o f

. ,

Permanent Brac in


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e rmanen rac ng

Top Chord

Typic a lly direc t app lied dec k

Could be purlins 24 o.c .

Bottom Chord

Can be ri id ceilin d irec tl a lied

24 o.c . purlins with d rywa ll

Drop c eilings will require user defined spac ing for la tera lbracin

Typic a lly 6 to 8 o.c .

Don t forget the d iagona l b rac ing!

La tera l Brac ing

Be sure webs line up --otherwise, T-b rac ing will be

Diagona ls a re essential

Who ha s responsib ility for Permanentrac ng esgn


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ecause o e un que na ure o eac russ p ro ec , e es wayto assure tha t the brac ing is hand led c orrec tly is to p rovide apermanent b rac ing design. Ac c ord ing to typic a l p rotoc ol, this

.overa ll build ing design and understand how the build ingc omponents a re to be integra ted . However, bec ause of the

with p roprieta ry LGSTs, the job may be best a ddressed by the

truss eng ineer. Regard less of who provides it, be sure the.

Brac in Deta ils


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e o ow ng a re examp es o an eng neere rac ng esgn.One shows the p ermanent web b rac ing required , the other is asheet o f add itiona l deta ils that must be a pa rt of the b rac ing

.

Bra c in Desi n


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Bra c in Desi n


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Light Gauge Steel Trusses

What Will Drive the Use of LGST


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nc rea sng y s r ng en re c o es Build ing designers love the fea tures & b enefits More c ost effec tive tha n trad itiona l materia ls

, ,accessories Arc hitec ts and engineers looking for ways to get the job done

The trend for p re-fabric a ted c omponents c ontinues to inc rease

In Conc lusion


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oranges by

portion o f the truss systemPut it in the spec ific a tionDon t forget to identify responsib ility for other anc illa ry

Shear b loc king and transfer framing, bent meta l

for dec k support, fasc ia materia l, and over-framing Understa nd ing truss nomenc la ture Tho roug hlyevalua ting proposa ls and b ids

Don t ust rab the lowest number and run with it Being c autious of the term Value Eng ineering Communicating!!!

In Conc lusion


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For Non-Combustib leCommerc ial/ Institutiona lConstruction...

Light Gauge Stee lTrusses are a great

alternative...

Summar


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e es gn ro ess ona s ou now e a e o:

Explain why Light Gauge Steel Trusses a re a Good Alterna tive

Exp la in a pp lic a tions for Proprieta ry LGST List and desc ribe Case Stud ies

Desc ribe the design proc ess for Fac tory-built LGST

Exp la in: Fabric a tion, Pac kaging , Shipp ing , & Insta lla tion of-

Compare and c ontrast a n LGST p roposa ls and exp la in whatmakes a c omp lete truss system

Links to more information a bout LGST


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g a uge ee ng neers ssoc a on :www.lgsea.com

. .

Aegis Meta l Framing www.aegismetalframing.com

Course Sponsor

AEGIS Metal Framing


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g

14515 N Outer 40 DriveSuite110

Chesterfield, MO 63017

Light Gauge Steel TrussesThe Specification, Design Manufacturing and

314-851-2234

E-mailjaltman@aegismeta lframing .com

Web

www.aegismetalframing.com

Course Numb er

Please note: you will need to c omplete the c onc lusion quiz online atronblank.com to rece ive credit

An AIA Continuing Educ a tion ProgramCred it fo r this course is 1 AIA/ CES HSW Learning Unit

Light Gauge Steel Truses Guide

Documents

Transcript of Light Gauge Steel Truses Guide