Tata Shaktee

8/10/2019 Tata Shaktee

1/31

ROOF AND W ALL CLADDING


2/31

BRAND 1

look

All new Galvanised Roof ing Sheets

BRAND 1

alike...

BRAND 2


3/31

Maxim um St rengt h

Unif orm Zinc Coat ing

Assured Th ickn ess

Sup erio r Packaging

Fixed and Transparent Pri cing

Superior Dist r ibut ion Net w ork

Righ t Hardness f or Roo f ing

Opt imum Chrom at ing

Excellent Zinc Adherence

Accurate Dimension

Print ed Thi ckness and Zinc Coat ing

Perf ect Overlapp ing


4/31

TATA Shaktee GC sheets tru ly last t he long est. Af ter a l l , they are bro ugh t t o you fro m th e house of

TATA's. The sheets pass th roug h str ing ent q ual i ty t ests th at ensure unif orm Zinc coat in g, p rop er

hardn ess for roo f ing , superior Zinc adherence, high t ensi le streng th and accurate d im ensions.

Al l th is and m ore add up t o th e qual i ty valued by m il l ions of consum ers over decades.

...but on ly t he best

st and t he t est of t im e.


5/31


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INTRODUCTION 1

THE SHAKTEE EDGE 2-5

TATA SHAKTEE SPECIFICATIONS 6-7

WIND FORCES 8-9

ROOF AND WALL CLADDING 10-12

TATA SHAKTEE WIDER - SAVINGS UNLIMITED 13

ACCESSORIES 14-17

GUIDELINES FOR INSTALLATION 18-21

GENERAL CARE AND MAINTENANCE 22-23

SHAKTEE EDGE - AT A GLANCE 24

OFFICE ADDRESSES 25

C O N T E N T S


7/31

Over the years, TATA Steel has altered t he land scape of t he roo fing ind ustry in Ind ia. The com pan y has been a

pioneer in the field of manufacturing superior quali ty TATA Shaktee Galvanised Corrugated (GC) sheets.

M anufactured w i th w orld-c lass techno logical expert ise, these GC sheets are stro nger and longer last ing th an

any o th er ord inary GC sheets. TATA Shaktee GC Sheets are no t on ly m ade o f virgin steel pr ocessed at TATA

Steel 's state-of-th e-art Cold Rol ling M i l l but also h ave uni fo rm Zinc coat ing o n t hem , w hich gives them the

required strengt h in f ight ing th e weather and to last long est.

L iv ing up to the company 's assurance of good qual i ty and t rus tworthy products , these sheets are

manufac tured to exac t parameters o f th ickness , length, wid th and Zinc coat ing as per the spec i f ied

requirements. In addi t ion to this, TATA Shaktee GC sheets are ISI cert i f ied under Bureau of Indian

Stan dar ds (BIS).

Al l in al l , TATA Shakt ee GC sheets give mo re value fo r m on ey and are the b est cho ice fo r anyon e lookin g

for a pro duct t hat w i l l per form year a f ter year.

This manu al has been created in order to m ake consum ers aw are of the best engineering pract ices involved

in instal lation and maintenance of Galvanised Corrugated Steel sheets used in Roof and Wall Cladding

appl icat ions. We have attempted to col late best pract ices recommended by various Indian and global

stand ards along w ith th ose received from pract ising shed fabricators and archi tects.

Please feel free to send you r sug gestion s/feedback fo r im pro vement s on t his manu al, i f any, to

Brand Manager - Tata Shakt ee, Tata Cent re, 43 Jawaharlal Nehru Road, Kolkata 700 071

I N T R O D U C T I O N

1


8/31

2

Low tensile strength of ordinary sheets results indamage/rupt ure caused by hailstorms and o ther externalforces.

Inferior t echnolo gy and process control results in uncleansteel surface leading to low adherence of Z inc coating.This causes the galvanised surface to p eel off result ing i nreduced sheet life.

Uneven tempering causes ordinary sheets to crack duringdri l l ing.

High t ensile strengt h (appro x 700 m pa) of TATA Shaktee GCSheets resist natural forces like hailstor ms and ot her externalforces.

Superior technology and process control ensures propersurface cleaning before coating. This means a cleaner steelsurface that result s in excellent Zinc adh erence.

Accurate tempering in TATA Shaktee GC Sheets resistcracks and f issures during drillin g.

TATA SHAKTEE G C SHEET ORDINARY GC SHEET

T H E E D G E

RIGHT HARDNESS FOR ROOFING

HIGH TENSILE STRENGTH

EXCELLENT ZINC ADHERENCE


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3

Thickness of t he sheet and t he Zinc coatin g app lied to it isnot m entioned and even if i t is , i t is generally incorrect. Asa result, custom ers are oft en cheated during purchase.

Uneven corrug ations and edge w aviness lead t o g aps inoverlapping, result ing in a badly fabricated roof.Unw anted part ic les and m oisture stuck betw een th e sheetoverlappings results in corrosion start ing from the jo int.

Non-uniform Zinc coating cause parts of galvanisedsurface with low Zinc coating to corrode faster. Thisreduces the sheet lif e drastically.

ORDINARY GC SHEET

Each sheet has its thickness and Zinc coatin g p rint ed on itto ensure that t he custom ers get w hat t hey have paid for.

Even corrugations ensure perfect overlapping w hichresults in im proved w eather-proof ing. M oreover, there isno unw anted retention of part ic les and mo isture betw eenthe overlapped jo ints. This prevents corrosion orig inat ingfrom o verlappings.

Un i fo rm 1 2 0 g sm Z in c co a t in g e n su re d b y th esophisticated FEED FORWARD X-RAY COATING GAUGEresults in even surf ace pro tectio n.

TATA SHAKTEE G C SHEET

UNIFORM ZINC COATING

ASSURED THICKNESS AND ZINC COATING

PERFECT OVERLAPPING

T H E E D G E


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4

Ordinary sheets,quite oft en, are of low er lengt h th an thestandard lengt h specified. As a result you g et lesser valuefor your m oney.

9.9Feet

3020mm

In ordinary GC sheets, the thickness is not printed andeven if it is, the actual thickness is usually lower than theth ickness claimed.

0 . 5 4 m m

In case of ordinary GC sheets, inadequate chromating onthe galvanised surface results in form ation o f w hite rust onth e sheets that reduces sheet lif e.

The length of the sheet is equal t o t he standard specif iedlength, g iv ing you true value for your m oney.

10Feet

3050mm

TATA Shakt ee GC sheets com e w it h assur ed t hickn ess. Thetolerance maintained is more str ing ent th an the standardsdefin ed by Bureau of In dian Stand ards (BIS).

0 . 6 O m m

Usage of th e best and adequate chromat e solut io n at t hegalvanis ing stage prevents form ation of w hite rust on thesheets. As a result, sheet lif e is enhanced.

ADEQUATE CHROM ATING

ACCURATE DIMENSION

ASSURED THICKNESS

T H E E D G E

TATA SHAKTEE G C SHEET ORDINARY GC SHEET


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5

Pricing of ordinary GC sheets is opportunistic and unfair,w hich m eans that prices are unstable and no n-transparent,thereby subject to change even o n a w eekly basis.

The Recom m ended Consum er Price of TATA Shaktee GCSheets ensures the required transparency and stability inpr ices across the stat es.

A superior d istr ibution network compris ing 3500 dealersand 28 distributors spread across the country ensuresexcellent reach and regular supply of TATA Shaktee GCSheets, as and w hen requ ired.

Nonexistence of authorised dealer network leads toirregular supp ly and even sales of substan dard p rod ucts.

TATA Shaktee GC sheets are packaged w ith Blue WovenHDPE (450 microns) and LDPE (250 microns) plasticsalongw ith edge prot ectors, tamp er proof seals and m etalja cket s on t h e t op t hat p ro t ect s sheet q u al it y, esp eci al lyduring t ransit .

Ordinary sheets are packaged w ith poor quali ty p last icswith a metal jacket on top that is susceptib le to damageduring transit .

OPPU TUNIS IC ELLING

RT S

NO

S IBUT

O

DI TR

I N

ONET

W RK

UNST

ABLE

ONTRANSPAREN

N

T

Bare Sheets

Woo den Sk i ds

M eta l Band

S t rapp i ng

Ordin ary Plast ic

P

RIC

E

Edge P ro tec tor

M eta l Band

S t rapp i ng

Ident i f i cat io n Tags

Tata Blue Seal

Wooden Sk i ds

Bare Sheets

Blue WovenHDPE

(450mi c rons)

LDPE (250 m icrons)

SRINAGAR

JAIPUR

PUNEHYDERABAD

CHENNAI

CHANDIGARH

DELHI

MUMBAI

AHMEDABAD

CUTTACKNAGPUR

GUWAHATI

JALANDHAR

DHANBAD

BERHAMPUR

SILIGURI

GHAZIABAD

AURANGABAD

FARIDABAD

INDORE

UTTARANCHAL

HUBLI

SOLAPUR

RANCHI

KOLKATAJAMSHEDPUR

PATNA

RAIPUR

SANGLI

SUPERIOR PACKAGING

STABLE AND TRANSPARENT PRICING

SUPERIOR DISTRIBUTION NETWORK

TIME

T H E E D G E

ORDINARY GC SHEETTATA SHAKTEE G C SHEET


12/31

6

Note:TATA Shakt ee tolerance levels are mo re strin gent as com pared t o BIS specifications ow ing to superior p rocesscontro l .

LENGTH

Before corrugat ion

After corrugat ion

DIAGONAL DIFFERENCE

DEPTH OF CORRUGATION

PITCH OF CORRUGATION

Should not d i f fermore t han 20 mm

Should not d i f fermore t han 20 mm

THICKNESS

800

840

910

1220

(gauge)

0.35

0.40

0.45

0.50

0.55

0.60

0.63

0.80

1.00

1.25

0.30

29

28

27

26

25

24

22

20

18

30 6

7

8

9

10

12

14

16

1830

2140

2440

2745

3050

3660

4270

4880

LENGTH WIDTH

(mm)THICKNESS

(mm) (mm) (feet)

PITCH

DEPTH

17.5 75

10 + +

11 + +

17.5

12.5

75

78

10 + +

1220

910

800

840

17.5 75 15 + +

Note:(1) Width of 12 20 m m is available from 0 .45 m m thickness onw ards. (2) Thickness of 0.60 m m in gauge t erm isreferred to as 24 "LOW".

S P E C I F I C A T I O N S

PHYSICAL PROFILE

DEPTH AND PITCH OF CORRUGATION

24

TOLERANCE LEVELS

TATA SHAKTEEBISPARAMETERS

WIDTH OF GC SHEETAFTER CORRUGATION

(mm)

NO. OF

CORRUGATIONS

PITCH OF

CORRUGATION

(mm)

DEPTH OF

CORRUGATION(mm)

WIDTH1 5 m m

5 m m

2.5 mm

.03 mm

+ 1 5 m m , - 0

+ 1 0 m m , - 0 m m

2 5 m m

+ 1 0 m m , - 0 m m

+ 1 5 m m , - 0

2 .5 mm

5 m m

.05 mm


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7

Not e: BIS recom m ends th ickness of 0.63m m w ith Zinc coating o f m inim um 275 gsm. (Refer to para 7.3, Note 1 on page2 of IS277: 1992).

TYPE OF COATING Galvanised (Zinc) Spangled

COATING WEIGHT 120 gsm (gram per square m etre), Class 8 (as per BIS)(For t a i lor m ade prod ucts Zinc coat ing, m ay vary betw een 60 -600 gsm)

THICKNESS

(mm)

APPROXIMATE WEIGHT (Kg)

PER SQUARE METRE

0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.63 0.80 1.00 1.25

2.25 2.65 4.20 4.55 4.803.00 3.40 3.80 6.10 7.45 9.25

0.5%.Note: 1) BIS tolerance for the "Bundle Weight" (70/72 running feet of sheets) is 2) Length of 16 feet (4880 m m ) is avai lable only f rom 0.40 m m thickness onw ards.

3) Weight per sheet for th ickness 1.00 and 1.25 mm has not been indicated in the above table sinceth ese are no t stand ard sizes. How ever, these sizes can be pro du ced on d eman d.

0.30 x 800

0.35 x 800

0.40 x 800

0.45 x 840

0.50 x 840

0.55 x 840

0.60 x 840

0.63 x 840

0.30 x 910

0.35 x 910

0.40 x 9100.45 x 910

0.50 x 910

0.60 x 910

0.63 x 910

0.80 x 910

0.45 x 1220

0.50 x 1220

0.60 x 1220

0.63 x 1220

0.80 x 1220

0.80 x 840

3.663

4.339

4.939

5.577

6.201

6.862

7.496

7.881

4.047

4.837

5.5646.283

6.991

8.485

8.961

11.149

8.378

9.370

11.289

11.877

15.473

10.051

4.296

5.007

5.766

6.508

7.235

8.013

8.753

9.205

4.724

5.656

6.4967.323

8.166

10.013

10.387

12.998

9.767

10.922

13.191

13.844

17.092

11.737

4.883

5.785

6.585

7.436

8.269

9.149

9.994

10.508

5.397

6.450

7.4198.377

9.322

11.313

11.948

14.866

11.170

12.493

15.052

15.836

20.631

13.402

5.494

6.508

7.408

8.365

9.302

10.293

11.244

11.822

8.346

7.256

6.071

9.425

10.487

12.727

13.441

16.724

12.566

17.815

23.210

16.934

14.055

15.077

6.137

7.153

8.238

9.297

10.336

11.448

12.504

13.151

9.280

8.081

6.748

10.461

11.666

14.304

14.838

18.569

13.952

19.776

24.417

18.844

15.603

16.767

7.325

8.678

9.877

11.153

12.430

13.724

14.991

15.762

11.129

9.674

8.095

12.566

14.000

16.980

17.922

22.298

16.755

23.754

30.946

22.579

18.740

20.102

8.592

10.015

11.533

13.016

14.520

16.027

17.505

18.411

13.000

11.313

9.447

14.645

16.332

20.025

20.773

25.997

19.533

27.687

34.184

26.381

21.844

23.473

( m m )

APPROXIMATE WEIGHT PER PIECE FOR VARIOUS LENGTHS OF SHEET (in Kg)

6f t(1830mm)

7f t(2135mm)

8 f t(2440mm)

9f t(2740mm)

10f t(3050mm)

12f t(3660mm)

14f t(4270mm)

9.767

11.570

13.169

14.871

16.537

18.298

19.989

21.016

14.838

12.899

10.793

16.755

18.680

22.626

23.896

29.731

22.340

31.672

41.262

30.105

24.986

26.803

16f t(4880mm)

COATING

APPROXIM ATE WEIGHT PER SQUARE METRE OF SHEET (for 120 gsm coat ing)

APPROXIMATE WEIGHT PER SHEET (for 120 gsm coat ing)

SIZE(THICKNESS

X

WIDTH)

S P E C I F I C A T I O N S


14/31

8

Speed of w ind creates considerable forces on bot h t op and b ott om sides of the Roof Cladding an d hence one

m ust consider w ind speed and i ts resul tant forces w hi le designing and instal l ing a roof. W hi lst t he fo rces

act ing inw ard throug h th e tops ide of t he roof ing sheet tend t o pu sh th e Roof Cladding d ow nw ards, theoutw ard forces act ing t hrough the bot tom side of the roof ing sheet tend to l if t t he Roof Cladding f rom i ts

fram e. Outw ard fo rces could b e generated by ei ther negat ive wind pressures out side the b ui lding o r po si t ive

w ind p ressure inside the b ui lding.

Outw ard forces act ing o n roof ing sheets th roug h bot to m side are m ost com m on and t hese forces m ust be

balanced b y providing r igh t spacing betw een t he Purl ins (Figure 1 on page 10) and by select ion of r ight

diamet er, length and num ber o f f asteners. In cyclonic areas, extra care mu st be t aken in designing and

instal lat ion of roof s by consul t ing archi tects or p rofessional shed fab ricators.

SPACINGS BETWEEN PURLINS (m m)

Wind Zone

I

Wind Zone

II

Wind Zone

III

Wind Zone

IV

Wind Zone

V

Wind Zone

VI

THICKNESS OF

SHEETS (m m)ROOF SLOPE

0.30

0.35

0.40

0.45

0.50

0.55

0.60

0.63

0.80

1 in 3

1 in 4

1090 1090 1090 1090 1090 1090

1070 1070 1070 1070 1070 1070

1230 1230 1230 1230 1230 1160

1220 1220 1220 1220 1220 1120

1320

1310

1400

1380

1480

1460

1550

1530

1620

1600

1650

1640

1860

1850

1320

1600

1800

1740

1310

1400

1380

1460

1410

1500

1450

1550

1500

1580

1520

1720

1660

1290

1250

1350

1300

1200

1350

1440

1400

1480

1440

1510

1460

1650

1590

1210

1170

1260

1220

1300

1270

1350

1330

1390

1350

1420

1370

1540

1490

1320

1310 1310

1400 1400

1380 1380

1480 1480

1460 1460

1550 1550

1530 1530

1620 1620

1600 1600

1650 1650

1640

1860

1850

1.00

1.25

2090

2000

2230

2130

1950

1880

2120

2050

1860

1880

2000

1950

1780

1720

1930

1860

1660

1610

1800

1740

2090

2000

2230

2130

1320

1 in 3

1 in 3

1 in 3

1 in 3

1 in 3

1 in 3

1 in 3

1 in 3

1 in 3

1 in 3

1 in 4

1 in 4

1 in 4

1 in 4

1 in 4

1 in 4

1 in 4

1 in 4

1 in 4

1 in 4

* Calculat ions are based on basic princip les of Structu ral Engineering in respect t o Strength and Deflect ion.

W I N D F O R C E S

RECOMMENDED SPACING BETWEEN PURLINS FOR DIFFERENT WIND ZONES*


15/31

9

BASIC WIND SPEEDIN METRE/SECOND

COLOUR CODE

55

50

47

44

39

33

WIND ZONE

VI

V

IV

III

II

I

Source: United Natio ns Development Program meWebsi te : ww w.undp.org

W I N D F O R C E S

WIND ZONES


16/31

10

Note: Roof s lopes w ith 1 in 3 and higher are prevalentin locations wit h high rainfal l /snow fal l

1

4

1 in 4 (14 )

1

3

Wh ile one of t he mo st im port ant roles of ro of ing is to f ight the w eather, they also have signi f icant ef fects on

th e aesthet ic, cost and durab i l ity of a bui lding . In Roof Cladding, f actors such as rainfal l , wind speed, height

of b ui lding and w alk ing w eight on roof s (arising ou t of m aintenance) have considerable ef fect on d esign ofroof slope, suppo rt ing stru ctures and spacing b etw een Purl ins (Figure-1).

Design parameters for Wal l Cladding

i s s i m p l e a n d s t r a i g h t f o r w a r d

compared to Roof Cladding. The

main considerat ion in the design is

spac ing be tween the suppor t s ,

known as Side Girt (equivalent of

Purl in s used in Roo f Cladd ing ). Windspeed and thickness of sheets play

m ajor role in arr iv ing at t he spacing

betw een Side Girt .

Overhang in Roof Cladding is important from the angle of complete weather-proofing of the building. While

End Overhang m aintained at the Eave End (Gut ter end) of the roof faci li tates prop er drainage of w ater

w itho ut d renching the inside of bui lding fro m it s fron t, the Side Overhang m akes sure the rain w ater does not

enter th e building from sides (Figure-4). Overhangs are recom m ended b elow as per go od engineering practice.

1 in 3 (18)

x y

END OVERHANG (x) SIDE OVERHANG (y)

300 mm 100 mm

Fig u re -2 Fig u re -3

Figure -4

Slope is a major component of roof design. In absence of adequate roof slope, there is danger of water

accum ulation, w hich can lead to leakage and reduced sheet l i fe. Mo st com m only used ro of slopes in India are 1

in 4 (14 ) and 1 in 3 (18) (Figure 2 & 3). How ever, various other slopes can be used d epending upo n t he intensity

of rainf al l and w ind f orce. In case of sinusoidal profi les, i t is recom m ended t hat o ne shou ld no t g o below slope of

1 in 12 (5). It is impo rtant to use sealants at th e end lap of sheets in case roof slope is below 5.

R O O F A N D W A L L C L A D D I N G

OVERHANG

Side Girt

Spacing betw eenSide Girt s

Ridge-end

Eave-end(Gut ter-end)

Purlin

Spacing betw een

Purl ins

Figu re -1

SLOPE


17/31

11

Not e: For roo f s lopes lesser th an 14 recom m ended end lap is 200 m m

150 m m

200 m m

FOR ROOF CLADDING FOR WALL CLADDING

100 m m

100 m m

ROOF SLOPE

2

OL P

in

00MM F

RSO E

1 4

150M FO

SLOPE

in3

MR

1

G.I. CRANK BOLT

G. C. SHEET

M S RECTANGULA R TUBE PURLIN

N LE D AP

OFE

TWOSHETS

Note: In areas of heavy rainfall, the laps at sides should be suitably increased..

FOR ROOF CLADDING FOR WALL CLADDING

1 CORRUGATIONS 1 CORRUGATION

Joint s on th e roof ing sheets, also know n as 'Laps', are critical in fabr ication o f leakageproof roo fs. Joint s on th e side of t he

roof ing sheet (along sheet length) is know n as Side Lap (Figure-5) w hile joint at t he end o f t he sheet (along sheetw idth ) is know n as End Lap (Figur e-6). Slope of th e roof plays a major ro le in d eciding t he area of laps.

1 in 3 (18 )

1 in 4 (14 )

Figu re -5

Figu re -6


JOINTS ON THE SHEETS

SIDE LAP OF SHEETS

END LAP OF SHEETS


18/31

12

L : Length o f roof ( in metre)

W : Width o f roof ( in metre)L : Length of GC sheet used (in metre)SN : Numb er o f sheets requi red for a g iven length and w idth o f roof , ( f ig .7) wi l l be = N XN L L WN : Num ber o f sheets requi red a long the w idth o f roofW

Tota l num ber o f sheets requi red w i ll be N x N ( for a g iven length and w idth o f roof , d imensions exp la ined in Figure-7)L W

LENGTH (L)

IDT

(W

W

H

)

Figure -7

2

2

4

6

8

10

12

14

16

18

20

23

27

31

35

39

1

2

3

5

6

7

9

10

11

13

14

17

20

22

25

28

2

3

5

7

9

12

14

16

18

20

23

27

31

36

40

45

2

3

5

7

9

11

13

15

17

19

21

26

30

34

38

42

3

5

10

15

20

25

30

35

40

45

50

60

70

80

90

10 0

915

1525

3050

4575

6100

7625

9150

10675

12200

13725

15250

18300

21350

24400

27450

30500

NO.OF SHEETS REQUIRED FOR DIFFERENT WIDTHS OF SHEETS

800 mm 840 mm

LENGTH OF ROOF

(mm) (feet) 910 mm 1220 mm

Note: (1.) End lap of 200 m m and Side lap of 112.5 m m considered to arr ive at nu m ber of sheets across length o f roof . (2.) Overhang of 300 mm at eave-end and 100 mm at r idge-end considered to arr ive at num ber of sheets across w idth of roof.

1 2 2 0 mm

9 1 0 mm8 4 0 mm

8 0 0 mm

N = (W + 0 .4) / L - 0.2W S

WIDTH OF SHEETNO. OF SHEETS

ALONG LENGTH OF ROOFNO. OF SHEETS

ALONG WIDTH OF ROOF

N = ( L + 0 .0 8 75 ) / 1 .1 0 75L

N = (L + 0 .0 8 75 ) / 0 .7 9 75L

N = (L + 0 .0 8 75 ) / 0 .7 2 75L

N = (L + 0 .0 8 75 ) / 0 .6 8 75L


NUMBER OF SHEETS REQUIRED FOR VARIOUS LENGTH OF ROOFS

CALCULATION OF NUMBER OF SHEETS REQUIRED FOR VARIOUS LENGTH AND WIDTH OF ROOFS:


19/31

13

1

1

2

2

3

4

4

5

6

6

7

9

10

12

13

14

2

3

5

7

9

11

13

15

17

19

21

26

30

34

38

42

1

2

3

5

6

7

9

10

11

13

14

17

20

22

25

28

3

5

10

15

20

25

30

35

40

45

50

60

70

80

90

100

915

1525

3050

4575

6100

7625

9150

10675

12200

13725

15250

18300

21350

24400

27450

30500

LENGTH OF ROOF

(mm) (feet )

NO. OF SHEET

REQD. FROM

840MM WIDE GC

NO. OF SHEET

REQD. FROM

1220MM WIDE GC

NO.OF

OVERLAPPING

SAVED

Lesser num ber of sheets required:You w il l requ ire lesser num ber of TATA Shakt ee Wider GC Sheets as com pared t o ot her narro w w idt hsof GC sheets available in th e market in or der t o cover a given roo f size.

Fewer join ts required:Lesser number of roofing sheets mean fewer overlaps which reduces wastage of steel at sideoverlapp ing s. Less nu m ber of overlapp ing s ensure sub stantial cost savings.

Fewer seepage po int s:Lesser number of joints mean fewer holes need to be dri l led to f ix TATA Shaktee Wider GC Sheets,resul t ing in low er num ber of seepage points on th e roof and enh anced sheet l i fe.

Fewer accessor ies requi red :

Few er ho les in f ixing TATA Shakt ee Wider GC Sheets reduce requ irem ent of fasteners and substant ial lyresult ing in cost saving s.

Greater savings:Al l the abo ve benef i ts resul t in un l imi ted m onetary savings.

S A V I N G S U N L I M I T E D

ADVANTAGES OF TATA SHAKTEE WIDER (1220 MM) GC SHEET

SAVINGS FROM TATA SHAKTEE WIDER (1220 MM) GC SHEET


20/31

14

The rubber washer should be 25 m m in d iameter and 3 m m th ick wi th 6 m m bore to su it 8 m m d iameterbol t s. This bon d b etw een rub ber w asher and b ol t ensures w ater proo f seal ing.

The G.I . f lat w asher is 25 m m in diamet er (i f i t is a round w asher) and 1 .60 m m thick w i th central hole to sui t 8m m d iameter f ixing bol t o r screw.

The sheets are fastened to purl ins (in case of Roof Cladding) or side girts (in case of Wall Cladding) bymin imum 8 m m d iamete r hook bo lt s at a m aximum p i t ch o f 375 mm .

Usage of r ecom m ended accessories leads to enhan ced l i fe of Roo fs and Walls. Poo r and substan dard qu ali ty

of accessories may adversely affect the superior quali ty of cladding sheets leading to reduced l i fe.

Accessories and t he claddin g m aterial sho uld h ave sim ilar l ife expectancies as th at of th e main stru ctur e and

hence cri teria f or selectin g t he accessories such as Fasteners, Gutt ers and Flashing s mu st be b ased o n t he

design l i fe of th e stru cture.

Researches executed o n causes of steel bui ldin g fai lur es w orld w ide indicate th at alm ost 80% o f fai lur es start

f rom th e fasteners. Since fasteners, used o n c ladding and structu re tog ether, const i tu te rou ghly 6-8% o f t he

entire pr oject cost, several bui ld ers have the ten dency to n eglect th is vital aspect of th eir project.

Fasteners used o n steel Roof and W al l Cladding m ust be of goo d q ual i ty and pro perly galvanized confo rm ing

to IS:730 stand ards. This w i l l go a long w ay in pro viding a w eather proof and long last ing roof. Di f ferentcomp onent s of g ood qual i ty fastener is depicted below in Figure-8.

There are various k ind of hoo ks and screws avai lable in th e market depend ing u pon the m aterial and t ype of

purl ins on w hich sheets need t o b e f ixed (Figure-9). G.I. Hook Bol t should be used for f ix ing sheets to ang le

Iron p url in s. G.I. Crank Bolt should be used for f ixing sheets to chann els or rectang ular/square tub es pu rl ins.

G.I. Coach screw (squ are head) sho uld b e used fo r f ixing sheets to w oo den p url in s on ly.

G. I. NUT

G. I. FLAT WASHER

RUBBER WASHER

RUBBER WASHER

J HOOK

G. I. CRANK BOLTG. I. HOOK BOLT

G. I. COACH SCREWSQUARE HEAD

Figu re -8 Fig u re -9

A C C E S S O R I E S

FASTENERS

TYPICAL FASTENERS FOR CLADDING TYPES OF HOOKS/SCREWS


21/31

15

Usage of b i tumen washer, commonly used wi th Jhoo ks, retains w ater/m oisture t hat leads to rust ingthat begin at the jo ints and spreads to the sheetreducing sheet l i fe.

Usage of rub ber w asher enh ances sheet l i fe. Therubb er washer does not absorb w ater or mo istureand t hus prevents the sheet f rom rust ing.

BITUM EN W ASHER

NEW A FTER FEW YEARS

RUBBER WASHER

N EW A FTER FEW YEARS

Usage of recommended fasteners enhance sheetl i fe.

N EW A FTER FEW YEARSFA STENER W ITH RUBBER W A SHER

Usage of p oor q ual i ty fasteners lead t o rust ing thatbegin at the jo ints and spreads to the sheet

reducing sheet l i fe.

FASTENER W ITH BITUM EN W ASHERNEW AFTER FEW YEARS

Usage of a luminium painted J hook, washer andnut that looks similar to galvanised accessorieslead to ru sting. This begin s at th e joints and spreadsto t he entire sheet, reducing sheet l i fe.

Usage of g alvanised J ho ok, w asher and n ut enhan cessheet l i fe by preventing corrosion at the joint s.

NEW A FTER FEW YEARS

ALUM INIUM PAINTED J HOOK AN D WA SHER

AFTER FEW YEARS

GALVAN ISED J HOOK AN D W ASHER

NEW


USAGE OF RUBBER WASHER

USAGE OF GALVANISED FASTENERS

LIFE COMPARISON OF FASTENERS USED WITH RUBBER AND BITUMEN WASHERS


22/31

16

Flashings are made fro m str ips of g alvanised m etal in order t o p rovide the essent ial w eatherproof ing at the

edges of the c ladding apart f rom making the f in ished job look neat. Flashings, depending upon their

placem ent over the c ladding , could be ei ther lon gi tu dinal or t ransverse. Long i tud inal Flashings run paral lel

to th e val leys (Figure: 12) and are m ade to sui t t he pro f i le of t he sheets. During instal lat ion , one m ust tu rn

do w n t heir edge to w ards the val ley in order t o achieve best w eather pr ot ection. Transverse Flashing s, also

know as Ridges, run p erpendicular to th e val leys. In ord er to achieve maxim um w eather-proo f ing, t he bent

edge of t he Ridge m ust si t on to th e prof i le of t he sheet (Figure: 13).

Figu re -12 Figu re -13

Recent developments in the f ie ld o f c ladd ing fas teners have promoted usage of se l f -dr i l l i ng screws

designed t o p rov ide except iona l corros ion resistance and w eather proo f ing . These screw s conf i rm toint ernat ional stand ards such as DIN, ASTM , AS and as th e nam e imp l ies, th ey are di rect ly screw ed

thro ugh sheets ont o t he pur l in w i th t he he lp o f a d r i l l m achine. Ident i f i ca t ion o f t hese screw s is depic ted

below .( Figu re - 10)

Figu re -10

IDENTIFICATION CODESof self-dri l l ing screw s is as fo l low s:

Screw Gauge(Thread outside

diameter)

Thread Pitch (t hreadsper inch)

Overal l length of t hescrew m easured fromunder the head (mm )

12 14 25X-

EPDM WASHER ( th ese w asher are co-po lymers, consist ing of ethylene,propy lene w i th prop or t ion o f d iene and t hey of fer ex tended l i fe w i th best w eather-proo f ing characterist ics und er extrem e climat ic cond i t ion)

SCREW GAUGE(gauge of a screw is determ ined by t he basic of t he th readout side diameter)

THREAD PITCH( thread pi tch is th e num ber of t hread crests coun ted along al inear m easurem ent of one inch)


SELF DRILLING SCREWS

FLASHINGS & RIDGES


23/31

17

50

100

150

200

03 0

400

500

90

80

70

60

50

40

30

20

10

10 0

0

4 000 50 00 600 0 7000 8000 9 000 10 000 110 003 000 1200 0

2Cross-sect ional area of gutter (mm ), For Gutter Slope > 1 in 500

2

WaterReceivingareaforeachDrainPipe(m

)

Rainfall intensity( mm/hou r )

Example for calculat ing

number of Drain P ipes

required:

DATA GIVEN:Rainfal l intensi ty = 100m m/h

2Gut ter area = 7500mmDrai n Pi pe d i ameter = 100 m m

2TWRR = 750 m

SOLUTION:

1 ) F o r t h e g i v e n r a i n f a l li n t ens i t y and Gut t e r a rea,

TWRD for a sing le drain p ipe is2

equa l t o 75 m ( see red dot t edl ine in the graph on lef t )2) Number of Drain Pipes

requi red wi l l be= TWRR / TWRD= 7 5 0 / 75= 10 Drain Pipes

Figu re -16Figu re -15

Drain Pipe 1

DrainPipe2

Drain Pip e 4 Drain Pip e 3

High Point

HighPoint H

ighPoint

DrainPipe5

Source: National Plumbing and Drainage Standards, Australia AS 3500.3.2:1998


Drainage of w ater f rom t he roof is extrem ely imp ortant in order to achieve comp lete w eather-proo f ing of

th e bui lding. A w el l designed w ater col lect ion system , thro ugh set of Gutt ers and Drain Pipes at eave-end,

not only prot ect pro perty and bui lding b ut also helps in w ater harvest ing .

Gutt ers (Figure-14), made o ut of galvanized m etal str ips, are instal led w i th a generous slope t o avoid w ater

accum ulatio n. To b e on safer side, Gutt ers sho uld have a

slop e steeper t han 1 in 50 0.Typical ly, slop e on h ou se gu tt ers

is m aint ained at 1 in 2 50. Design o f Gut ters and Drain Pipes

is based on rainfal l intensi t ies (mm /hour) f or a given terr i tory

along w i th w ater receiv ing area of the roof . Total Water

Receiving area of Roof - TWRR can be calculat ed fro m th e

plan of t he structu re. To al low for t he slope of t he roof,

increase th e plan area by 1% fo r every degree of in crease in

slop e up t o 40 degr ee. For a given rainf al l intensity and cross

section al area of Gut ter, Tot al Wat er Receiving area of a

sing le Drain Pipe (TWRD) can b e calculated fro m t he grap h belo w. The diamet er of Drain Pipes considered in

th e graph is 100 m m . The required num ber of 100 m m diameter Drain Pipes can b e arr ived b y div iding TWRR

by TWRD. An example calculating the required numbers of Drain Pipes is indicated in Figure-15. An

i l lustrat ive examp le of Drain Pipe arrangem ent along w i th h igh po ints of w ater drainage is indicated below

(Figure-16).

Roofing Sheet

Gutter Purl in

Gut ter

5 0 m m

Figur e -14

ROOF DRAINAGE & GUTTERS


24/31

18

Check f latn ess, slope and o verhang o f t he fram e on w hich the sheets are to be laid. Please rem emb er that

any correct ion in t he fram e required after laying t he sheets w i l l be di f f icul t and at t im es imp ossible to

rectify.

Before l i f t ing the sheets on t o t he roof , check i f they are r ight side up.

Place bund le of sheets over and near the f i rm supp orts and not at th e mid-span of roo f m emb ers.

Sheets are norm al ly laid f rom lef t t o r igh t com m encing at Eaves, explained in f igu re-17 w i th sheets being

num bered in ord er o f f i x ing.

The f i rs t sheet is la id at t he Eaves, r ight angled (90 d egrees) to the p url in w i th a s ide lap o f o ne and a hal f

corrugat ion.

The minimum free overhang at Eaves must not exceed 300 mm. Care should be taken to ensure a

minimum overhang of 100 mm at the s ide of the sheets. Ensure that the roof ing sheets overhang

min im um 50 m m in to the Gut ter a t eave-end.

It is general ly con sidered g oo d p ractice to u se fasteners along side-laps of sheets.

To b e on safer side, do no t f ix fasteners less than 25 m m from the end o f t he sheets. M axim um pi tch

betw een tw o fasteners, across th e widt h of t he sheet, shou ld be 375 m m .

Wh ile lay ing th e f i rst sheet at lef t of eave-end, p lease ensure th at i t is correct ly located in relat ion to oth er

parts of t he bui lding such as end and/or s ide-w al l.

Check al ignm ent of sheets at repeated intervals. I t is imp ort ant t o keep th e gut ter-end and r idg e-end of

al l sheets in a straig ht l ine. This can b e achieved b y keepin g t he sheets paral lel w ith respect t o t he first

sheet.

One can eith er f ix each sheet com pletely befo re laying t he next or can fix th e sheet suff icient ly to ensure i t

can' t m ove, com plete laying al l sheets at on e row and t hen retu rn t o p lace all interm ediate fasteners.

G U I D E L I N E S F O R I N S T A L L A T I O N

FOR ROOFING


25/31

19

Figu re -17

In Roof Cladding, fo r m aximu m w ater-t igh tness, fastening screw s th roug h t he crest o f t he sheets on t o

th e purl in is hig hly recom m ended (Figu re 5 , Page 11). Alw ays drive screw s perp endicular to th e sheet and

at t he centre of t he corrug ation . Placing screws on val leys m ay be suscept ible to leakage in Roo f Cladd ing.

The sheets on th e next ro w are f ixed s im i larly making an end lap ( joint along t he length of the sheet -

Figure 6 , Page 11) o f m in imum 150 m m.

For Roof Cladding, a l low a min imu m end- lap of 200 m m for s lopes of 5 to 14 degree, and 150 m m for

slopes above 14 degree. For w al ls, allow m inimu m end lap of 10 0 m m .

For slopes below 1 in 4 i t is recom m ended to u se sealant at th e end lap w i th a minim um 3 m m b ead of

nat ural cure si l l icon sealant along th e centr e l ine of t he fastener hole.

Wh ere four sheets m eet at th eir corn ers, the to tal th ickness becom es very th ick. This gives a hum p at t he

corners. To p rovide neat f i t t o t he sheets at th is junct ion any tw o corn ers of the d iagonal ly oppo si te sheets

have to b e cut (m i tred). Mi tr ing m eans cutt ing of corners of t he sheets to t he measurement of s ide lap

and end lap of the sheets.


RIDGE-END

1110987 12

54321 6

RIDGE PURLIN

EAVE-END

(Gut ter-end)

OVERHANG AT EAVES 3 0 0 m m

PURLIN

EAVES PURLIN

OVERHANG AT SIDES

1 0 0 m m


26/31

20

In Wall Cladd ing f asteners are usually placed in t he val ley of t he sheets since wat er penetr ation is no t a

pro blem in Wall Cladd ing . Fasteners at val leys are less no ticeable and d o no t af fect t he aesth etic of t he

Steel Cladding. Also fasteners f ixed on valleys of Wal l Cladding m inimize the r isk of d eform ation of prof i le

since th e fastener rests f lat ag ainst i ts sup po rt, i .e. Side Girt (Figu re1, Page 10).

How ever, w hen val ley-fixed, the claddin g needs a side-lap fastener in al l laps, in ord er to h old t he pro fi les

of tw o sheets tog ether (Figure19, Page 21).

Figu re -18

Care shou ld be t aken t o ensure that t he sheets do not but t against each ot her. The gap b etw een each

m itred corner shou ld be appro xim ately 2 m m . (The tw o diago nal ly m i tred corners being covered by th e

uncut corners of th e covering sheets w i l l provide for perfect seal ing against w eather). M i tr ing should be

do ne by carpent er's saw and sheets should n ever be chipp ed.

At t he r idge end o f roof ing, w ind can p ush w ater up und er the r idge, in to t he bu i ld ing. In ord er to arrest

this prob lem, val leys of t he sheets are bent upw ard at the r id ge-end of roof ing (Figure-18). This process

blocks the val leys at r idge-end th ereby prevent ing w ater f rom entering th e bui lding t hrou gh r idg e-end.

This process is hig hly useful in ro of s w ith slop es below 1 in 2 (25). In cont rast, val leys at t he eave-end o f

roof ing sheet are bent d ow n in order to achieve enhanced weatherpro ofn ess and sm oot h f low of w ater

into th e Gutters. Bending of sheets at valleys can b e don e w ith the h elp of m ulti-grip p liers or a sliding spanner.


FOR WALL CLADDING


27/31

21

Figu re -19

Wh en the ai r in a bui lding in cont act w i th m etal cladding is w armer th an the c ladd ing, m oistu re in th e ai r can

condense on the inside of c ladding. Condensat ion can lead to deteriorat ion of bui lding components,

staining o f cei ling & w al ls and even deteriorat ion o f i tem s stocked inside th e stocking area. The am oun t o f

condensat ion depends upon the amount of moisture present in the ai r and this varies wi th c l imat ic

condi t ion s. Act ivi t ies w i thin a b ui lding such as w ashing and d ry ing of c loth s, cooking, show ering etc. may

also add substant ial ly to th e amou nt of m oistu re in the ai r. In t he event of extrem e mo istu re cont ent ins ide

the b ui lding, i t is essent ial to ei ther keep c ladding aw ay from m oist atm osphere inside th e bui lding o r vent

substant ial am oun t of ai r moisture to the out side of the bui lding.

To m inimize the r isk of condensat ion on th e inner-side of c ladding a vapou r barr ier is of t en used t o p revent

contact of w arm m oist ai r w i th ro of ing . Ref lect ive foi l laminat es are com m only used f or t his purp ose. Such

foi ls are also simp le, inexpensive and very ef fect ive metho d to contro l heat. Ad di t ion al heat insulat ion is

oft en achieved by using b ulk insulat ion blankets, w hich is a com binat ion of ref lect ive foi l laminates, glass

w ool and w ire m esh laid dow n on t he frame before instal l ing the coated sheets.


CONDENSATION & HEAT CONTROL


28/31

22

Handling:For p erson al safety i t is recom m ended t o w ear clean dry gloves w hile hand ling t he sheets. Sl iding

of sheets over rou gh surfaces or o ver each ot her resul ts in scratches and upro ot ing Zinc fro m th e sheet

surface.

Storage:Due t o capil lary action, m oisture easi ly enters betw een th e surf aces of stacked sheets. In areas of

high humidi ty, wind takes them between the sheets. The trapped moisture between the sheets cannot

evaporate easi ly leading to deteriorat ion o f t he surface coat ing , a phenom enon kno w n as Wh i te Rust ing.

This leads to redu ced l i fe of sheets and p oo r app earance. In areas of high hu m idit y levels, i t is advisable to

have exhaust fans to reduce hum idi ty level ins ide t he sheet sto rage po int .

I f the sheets are not required for immediate use, i t should be stacked neat ly and c lear of the ground at

covered space. It is advisable to prot ect th em w i th w aterproof covers.

I f stacked sheets becom e w et, separate it w i thou t d elay, w ipe i t w i th a c lean c loth or saw dust and stack i t

und er sun t i l l i t dr ies tho roug hly.

Keep th e stacked sheets as far as possible aw ay from th e non -com pat ible m aterial as ind icated in Table-1.

Marking, cutt ing and drilling during installation:Avoid usage of b lack pencils, i .e. lead pencils, to m ark a

galvanised surface as the graphite content can create an electric cel l when wet and this may cause

deteriorat ion of the f in ish o f surface. One can u se coloured p encils or a f ine fel t - t ipped m arker.

For cutt ing t hin m etal sheetson si te, i t is recom m ended to use a hand o r electr ic saw w i th a m etal -cut t ing

blade since i t pr od uces lesser dam aging m etal part icles and b urr o n t he sheets.

Holes on t he sheetsshou ld be m ade by dri l l ing. Use of pun ch in m aking holes shou ld be avoided as i t m ay

not prod uce a c lean cut hole and m ay even d amage t he prof i le of t he sheet.

G E N E R A L C A R E A N D M A I N T EN A N C E


29/31

23

TABLE- 1 : LIST OF NON -COM PATIBLE M ATERIALS

Limestone (com m only used in colouring th e cement w al ls)Pesticides

Wet and d ry concrete

Soils

Lead

Copper

Uncoated steel

Carbon (in pencils and some rubbers)

Chemical ly t reated wood or plywood

M aterials having excessive m oisture cont ent

(Non-seasoned timber, bitumen sheets and washers)

Not e: The l ist m ent ioned ab ove is not exhaust ive. In case of d oub ts on com patibi l i ty of ot her prod uctsbeing used w i th roo f ing sheets but no t m ent ioned abo ve, k indly seek advice from the m anufacturer ofGalvanised ro of ing sheets.

Maintenance:Besides roof design and th e environm ent, m aintenance also p lays an im po rtant role on t he

l i fe of a roof o r w al l. Maint enance includes the fol low ing:

Preferably, w ashin g should be do ne at least every six mon th s and m ore freq uent ly in coastal areas w here

m oisture in at m osphere cont ains high level of sal t .Washing of roof is also recom m ended in areas of high

industr ial izat ion , w hich have higher cont ent o f oxides of sulphu r, ni t rog en and chloride sal ts along w i th

hum idi ty in th e air.

Regular inspect ion of roof s and w al ls for prob lems before they become m ajor corrosion s i tes.

Remo val of fo reign p articles such as leaves and d ebris fro m gu tt ers and f lashing s.

Keep Wall Cladd ing s free of soi l , concrete and d ebris near th e grou nd .

Contact w ith incompatible material:To enh ance l i fe of galvanized steel sheets, it is imp ort ant to no te i ts

compat ib i l i ty wi th o ther commonly used mater ia l in cons t ruc t ion. Contac t wi th some non-compat ib le

m aterial and even w ater or m oistu re f low ing f rom such m aterial can adversely af fect th e l ife of the sheets.

G E N E R A L C A R E A N D M A I N T E N A N C E


30/31

Infer ior and outdated technologyresults in unclean steel surfacel ead i ng t o Z i nc pee l -o f f andreduced sheet l i fe.

Low Zinc coat ing, not ver i f iablethrough naked eye whi le buyingnew GC sheet, results in lowersheet l i fe.

U n e v e n c o r r u g a t i o n s l e a dt o g a p s i n o v e r l a p p i n g t h a tensures a badly fabr icated roof and

poor w eather p roof ing .

I nadequa te c h roma te s o l u t i onresul ts in form at ion of w hi te rust .

Ordinary sheets are packaged in apoo r qu al ity p last ic th at resul ts indam age to sheets.

Pricing of ordinary GC sheets isoppurtunist ic and unfai r , which

m eans th at prices are unstable andprone to opp or tun ism

A poor d istribu tion netw ork in absenceof distribution guidelines results inirregular supply of GC sheets.

The thickness printed is very oftenincorrect and low er to the standardspecif ied th ickness.

GC SHEET ATTRIBUTESSI.No.

TATA SHAKTEE GC SHEET ORDINARY GC SHEET

Accurate tempering resists cracksand f issures.

1 Hardn ess inRoofing Sheets

Uneven tempering causes cracksdur ing instal lat ion.

Tensile Str eng th

Zinc Adherence

Zinc CoatingTechnolo gy

Zinc M ass

Overlapping

Physical Dimension

Chromat ing

Thickness

2

3

5

6

7

8

9

4

H i g h t e n s i l e s t r e n g t h r e s i s t sexternal f orces.

Low tensi le strength results indam age and dent s.

Superior technology and processcontrol leads to c leaner steelsurface that enhan ces sheet l i fe.

Uni form 120 gsm Zinc coat ingth rou gh 'Feed Forw ard X-Ray

Coat ing Gauge ' ensures evensurface prot ect ion.

Non-uni form Zinc coat ing causespart s of GC sheet t o corro de faster.

Correctly printed thickness andZinc coating on sheet assures truevalue fo r m oney.

Ev e n c o r r u g a t i o n s e n s u r ep e r f e c t o v e r l a p p i n g t h a tresult s in a neat roof stru cture.

Length o f sheet equal or m ore thanstandard speci f ied length.

L e n g t h o f s h e e t l o w e r t h a nstandard specif ied lengt h.

Usage of the best and adequatec h r o m a t e s o l u t i o n p r e v e n t sform at ion o f w h i te rust .

10

11

12

Packaging

Pricing

D ist r ibu t ion Network

Packaged w ith Blue W oven HDPE (450microns) and LDPE (250 microns)plastic and shielded by the edgepro tecto r that preserves sheet qu ality.

The Recom m ended Consum er Price(R C P )ens u res t ha t p r i c es a re

uni fo rm and t ransparent across thestate.

A netw ork com prising 3500 dealersand 2 8 distrib ut ors ensures excellentand regu lar sup ply.

Thickness of th e sheet is equal to ormore than the standard speci f iedthickness pr inted on the sheet.

4

E D G E - A T A G L A N C E


31/31

LIMITED

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