Ruukki Lightweight Purlins Technical Manual

CFI.001EN/08.2011/PR

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Technical Manual

Lightweight purlins

Rautaruukki Corporation U PL 138 (Suolakivenkatu 1), FI-00811 Helsinki, Finland S +358 (0)20 59 11 X +358 (0)20 592 9088 w www.ruukki.comCopyright 2011 Rautaruukki Corporation. All rights reserved. Ruukki, Rautaruukki, More with Metals and Ruukkis trade names are trademarks or registered trademarks of Rautaruukki Corporation.

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1 Ruukki lightweight purlins

1.5 Sections Materialthicknessofsections1.0-3.0mm Sectionheights100-400mm Maximumlength18m(roll-formed) Tolerancestandardsappliedtocross-sections: - Press braked: EN 1090-2 - Roll formed: EN 10162 The Z section is excellently suited as a roof purlin. The major principal inertia axis is in pitched roofs with normal inclination in an approximately vertical position and thereby provides optimum load bearing capacity against the weight of structures and snow. The second momentofareaabouttheminoraxis,ontheotherhand,isso low that it is usually advisable to tie the sheet section on the slope of the roof to the opposite slope by a ridge moulding. The Z section is installed on the roof with the upper flange pointing toward the ridge. Z sections are applicable also as wallpurlins,installedwiththeouterflangefacingdown. C sections can be used as wall purlins or wall posts. The C section differs from the Z section by its centre of torsion, which in the C section is on the back side. Due to torsion, a vertical load acting on the section causes a transverse forcecomponentontheflangeofthesection,actingfromthe web up toward the upper flange. If C sections are used as roofpurlins,theyneedtobeinstalledwiththeupperflange pointing toward the ridge. As wall purlins, on the other hand, they are installed with the flange facing up, whereby wind pressure loads partly counteract the self-weight of the wall structure. With wind suction loads, the transverse force components strengthen one another, and tie rods may be requiredtocounteracttheirinfluence. A sigma section exhibits several plane areas separated by folds. This makes the manufactureofsigmasectionsmorecomplex than the manufacture of Z and C sections, but this is compensated by the higher durability values owing to the better efficiency of the dimensionally smaller plane areas. Thanks to this improved efficiency, the height of sigma profiles can be increased more than the height of Z and C sections. Sigma sections can be used on longer spans, or e.g. in sigma frameworks which are used in large span buildings to achieve moderate spans. A sigma framework is built joining two sigma sections back-to-back with 8-12mm distance pieces, with similar gauge sheet used as gusset pieces. The top hat section is wider than the sections referred to above. This gives it considerably higher lateral stiffness, which makes it suited to applications where the purlin is subjected to transverse loads, as well. Top hat purlins are attached directly from the flanges. They are used as roof purlins,wallpurlinsor,forexample,astrusschords.3

Table of contents1 1.1 1.2 1.3 1.4 1.5 1.6 Ruukki lightweight purlins ........................................................................................ 3 Advantages of lightweight purlins ................................................................................. 3 Material of lightweight purlins ....................................................................................... 3 Manufacture of Ruukki lightweight purlins .................................................................... 3 Cross-sections of Ruukki lightweight purlins ................................................................ 3 Sections........................................................................................................................ 3 Geometries and characteristics of cross-sections. ....................................................... 4 Lightweight purlin Z ...................................................................................................... 4 Lightweight purlin C ...................................................................................................... 6 Lightweight purlin Sigma .............................................................................................. 8 Lightweight purlin Hat ................................................................................................. 10 Structural systems ................................................................................................... 12 Single span system .................................................................................................... 12 2.1.1 Single span system, purlin designation diagram ............................................ 13 2.1.2 Single span system, purlins............................................................................ 14 2.1.3 Single span system, support cleats ................................................................ 15 Double span system ................................................................................................... 16 2.2.1 Double span system, purlin designation diagram........................................... 17 2.2.2 Double span system, purlins .......................................................................... 18 2.2.3 Double span system, support cleats .............................................................. 19 Sleeved system alternative in Ruukkis PurCalc software....................................... 20 2.3.1 Sleeved system, purlin designation diagram .................................................. 21 2.3.2 Sleeved system, purlins ................................................................................. 22 2.3.3 Sleeved system, support cleats...................................................................... 23 Overlapped system recommended by Ruukki......................................................... 24 2.4.1 Overlapped system, purlin designation diagram ............................................ 25 2.4.2 Overlapped system, purlins ............................................................................ 26 2.4.3 Overlapped system, support cleats ................................................................ 27 Hole design principle for manufacture ........................................................................ 28 Types of holes ............................................................................................................ 29 Support cleats ............................................................................................................ 30 Factors to be considered in the use of lightweight purlins ................................. 31 Torsional rigidity.......................................................................................................... 31 Improving torsional rigidity.......................................................................................... 31 Local buckling............................................................................................................. 31 Distortion of section .................................................................................................... 31 Resistance to support reactions ................................................................................. 32 Purlinsthataresupportedattheflange ..................................................................... 32 Transverse rigidity ...................................................................................................... 32 Unsupportedlowerflange .......................................................................................... 32 Unsupportedlowerflangeundercompression ........................................................... 33 Cantilever purlin ......................................................................................................... 33 PurCalc purlin design software .............................................................................. 34 Handling, transport and storage of lightweight purlins ....................................... 34 Handling ..................................................................................................................... 34 Transport .................................................................................................................... 34 Storage ....................................................................................................................... 34 Installation of lightweight purlins ........................................................................... 34

1.1 Advantages of lightweight purlins Ruukki offers wide range of lightweight purlins with high quality, durability and versatility of shapes and applications. Production technology and top quality raw materials assure of high load bearing capacity and stiffness leading to increase of span lengths. Purlins are widely applied as secondary roof and wall structures for almost all kind of buildings. Ruukki lightweight purlins offer several considerable advantages over alternative structures: he purlins are lightweight in proportion to their load T bearing capacity. Thus, roof structures built using lightweight purlins are very light. he use of material is very efficient. Owing to the high T strength of the base material, the required load bearing capacity is achieved with a smaller cross-sectional thickness, which translates into savings in materials and costs. ightweight purlins produce savings in transport costs. L The purlins require little space in transport, purlins for quite a large roof can be transported as a single delivery. ocalincreaseoftheloadbearingcapacityoflightweight L purlins is easy, by e.g. lapping purlins inside each other without having to make changes in the structural system of the whole roof or wall. onger spans are possible with lightweight purlins than L with alternative applicable solutions. ightweightpurlinsaremadeofzinc-coatedmaterialwith L good corrosion resistance. This makes lightweight purlins applicablealsoindifficultconditions. ightweight purlins are fully recyclable material. Waste L steel can be reused in the roof as weather protection, and the reuse of the whole roof at the end of its service life requires only little energy. 1.2 Material of lightweight purlins Lightweight purlins are made of cold rolled thin gauge steel sheet, which is delivered in coils. The material of the hot dip galvanised (20m) thin gauge steel sheet is grade S350GD+Z275, in compliance with EN 10346. The yield strength of the steel sheet is minimum 350N/mm. 1.3 Manufacture of Ruukki lightweight purlins Lightweight purlins can be roll formed or press braked from cold rolled thin gauge steel sheet. The purlins can also be pre-punched at factory. 1.4 Cross-sections of Ruukki lightweight purlins

2 2.1

2.2

2.3

2.4

2.5 2.6 2.7 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 4 5 5.1 5.2 5.3 6

Z

C

Sigma

Hat

Section dimensions shown at chapter 1.6.2

1.6 Geometries and characteristics of cross-sections

Lightweight purlin Z Steel grade: Yield strength: Tensile strength:

S350GD+Z fy = 350 MPa fu = 420 MPa

Purlin Z Cross-section geometriesNo. Type of purlin Thickness Height Width of wide flange Width of narrow flange Fold Weight Cross-section area, gross Cross-section area, effective Centre of gravity Centre of gravity

Purlin Z Cross-section characteristicsNo. Type of purlin Thickness Moment of inertia, gross Section modulus, gross Moment of inertia, effective/ Top flange compressed Section Moment of Section modulus, inertia, modulus, effective/ effective/ effective/ Top flange Bottom flange Bottom flange compressed compressed compressed Radius of gyration Max. bending moment, in span/ Top flange compressed Max. bending moment, in span/ Bottom flange compressed

tnom mm 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. Z350 Z300 Z250 Z200 Z150 Z120 Z100 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 2,00 2,50 3,00

H mm

A mm 45,00 45,40 46,00 47,00 45,00 45,40 46,00 47,00 45,00 45,40 46,00 47,00 70,00 71,00 72,00 73,00 70,00 71,00 72,00 73,00 89,00 90,00 91,00 92,00 90,00

B mm 39,00 39,40 40,00 41,00 39,00 39,40 40,00 41,00 39,00 39,40 40,00 41,00 62,00 63,00 64,00 65,00 62,00 63,00 64,00 65,00 81,00 82,00 83,00 84,00 82,00 83,00 84,00

C mm 18,00 18,00 18,00 18,00 18,00 18,00 18,00 18,00 18,00 18,00 18,00 18,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 30,00 30,00 30,00

g kg/m 1,63 1,96 2,45 3,27 1,81 2,17 2,71 3,61 2,04 2,45 3,06 4,08 4,36 5,81 7,26 8,71 4,92 6,56 8,20 9,84 5,95 7,93 9,91 11,89 8,87 11,09 13,31

Agross cm2

Aeff cm2

Yp mm 40,60 40,60 40,60 40,60 40,50 40,50 40,50 40,50 40,30 40,30 40,30 40,30 64,90 64,90 64,90 64,90 64,70 64,70 64,70 64,70 83,70 83,70 83,70 83,70 83,60 83,60 83,60

Zp mm 50,40 50,40 50,40 50,40 60,50 60,50 60,50 60,50 75,70 75,70 75,70 75,70 101,10 101,10 101,10 101,10 126,30 126,30 126,30 126,30 151,30 151,30 151,30 151,30 176,20 176,20 176,20 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. Z350 Z300 Z250 Z200 Z150 Z120 Z100 tnom mm 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 2,00 2,50 3,00 Iy cm4 31,155 37,607 47,262 63,289 47,935 57,866 72,727 97,403 81,548 98,450 123,746 165,761 333,533 447,103 560,349 673,275 565,589 758,256 950,410 1142,055 998,750 1339,303 1679,111 2018,181 1956,978 2453,684 2949,382

2,03 2,45 3,08 4,13 2,22 2,68 3,37 4,52 2,51 3,03 3,81 5,11 5,50 7,38 9,25 11,13 6,23 8,36 10,48 12,61 7,52 10,09 12,65 15,21 11,20 14,05 16,90

1,22 1,72 2,42 3,64 1,22 1,71 2,43 3,69 1,21 1,70 2,42 3,72 2,77 4,67 6,56 8,56 2,75 4,63 6,55 8,59 2,63 4,57 6,85 9,19 4,75 7,09 9,51

Wy cm3 6,124 7,378 9,244 12,319 7,857 9,469 11,871 15,834 10,705 12,906 16,190 21,616 32,753 43,798 54,756 65,630 44,516 59,562 74,508 89,356 65,688 87,940 110,071 132,080 110,463 138,303 166,008

Iyeff cm4 28,509 36,787 47,262 63,289 42,517 56,178 72,727 97,403 69,252 91,721 123,285 165,761 283,572 434,899 560,349 673,275 459,302 706,889 941,654 1142,055 703,886 1104,498 1531,571 1954,500 1585,278 2198,183 2803,871

Wyeff cm3 5,583 7,319 9,244 12,319 6,736 9,364 11,871 15,834 8,465 11,910 16,167 21,616 25,933 43,351 54,756 65,630 32,522 54,572 74,238 89,356 38,532 65,606 96,944 129,298 79,693 117,355 156,077

Iyeff cm4 29,269 37,566 47,262 63,289 43,610 57,166 72,727 97,403 70,950 93,081 123,153 165,761 290,230 439,243 560,349 673,275 469,740 712,819 940,734 1142,055 717,448 1125,651 1548,546 1953,385 1611,874 2218,175 2798,258

Wyeff cm3 5,517 7,365 9,244 12,319 6,681 9,267 11,871 15,834 8,430 11,653 16,039 21,616 25,885 42,482 54,756 65,630 32,569 53,299 73,187 89,356 38,677 65,707 95,735 125,158 79,741 115,895 151,283

iy cm 3,918 3,918 3,917 3,915 4,647 4,647 4,646 4,642 5,700 5,700 5,699 5,695 7,787 7,784 7,783 7,778 9,528 9,524 9,523 9,517 11,524 11,521 11,521 11,519 13,219 13,215 13,211

Mb,Rd kNm 1,954 2,562 3,236 4,312 2,357 3,277 4,155 5,542 2,963 4,169 5,659 7,566 9,077 15,173 19,165 22,970 11,383 19,100 25,983 31,275 13,486 22,962 33,931 45,254 27,893 41,074 54,627

Mb,Rd kNm 1,931 2,578 3,236 4,312 2,338 3,243 4,155 5,542 2,950 4,079 5,614 7,566 9,060 14,869 19,165 22,970 11,399 18,655 25,615 31,275 13,537 22,998 33,507 43,805 27,909 40,563 52,949

100

120

150

200

250

300

350

91,00 92,00

4

5

Lightweight purlin C Steel grade: S350GD+Z Yield strength: fy = 350 MPa Tensile strength: fu = 420 MPa

Purlin C Cross-section geometriesNo. Type of purlin Thickness Height Width of wide flange Width of narrow flange Fold Weight Cross-section area, gross Cross-section area, effective Centre of gravity Centre of gravity

Purlin C Cross-section characteristicsNo. Type of purlin Thickness Moment of inertia, gross Section modulus, gross Moment of inertia, effective/ Top flange compressed Section modulus, effective/ Top flange compressed Moment of inertia, effective/ Bottom flange compressed Section modulus, effective/ Bottom flange compressed Radius of gyration Max. bending moment, in span/ Top flange compressed Max. bending moment, in span/ Bottom flange compressed

tnom mm 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. C350 C300 C250 C200 C150 C120 C100 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 2,00 2,50 3,00

H mm

A mm 45,00 45,40 46,00 47,00 45,00 45,40 46,00 47,00 45,00 45,40 46,00 47,00 70,00 71,00 72,00 73,00 70,00 71,00 72,00 73,00 89,00 90,00 91,00 92,00 90,00

B mm 39,00 39,40 40,00 41,00 39,00 39,40 40,00 41,00 39,00 39,40 40,00 41,00 62,00 63,00 64,00 65,00 62,00 63,00 64,00 65,00 81,00 82,00 83,00 84,00 82,00 83,00 84,00

C mm 18,00 18,00 18,00 18,00 18,00 18,00 18,00 18,00 18,00 18,00 18,00 18,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 26,00 30,00 30,00 30,00

g kg/m 1,63 1,96 2,45 3,27 1,81 2,17 2,71 3,61 2,04 2,45 3,06 4,08 4,36 5,81 7,26 8,71 4,92 6,56 8,20 9,84 5,95 7,93 9,91 11,89 8,87 11,09 13,31

Agross cm2

Aeff cm2

Yp mm 14,70 14,70 14,70 14,70 13,40 13,40 13,40 13,40 12,00 12,00 12,00 11,90 20,40 20,40 20,40 20,40 18,00 18,00 18,00 18,00 22,30 22,30 22,30 22,30 21,20 21,20 21,20

Zp mm 50,40 50,40 50,40 50,40 60,50 60,50 60,50 60,50 75,50 75,50 75,50 75,50 101,10 101,10 101,10 101,10 126,30 126,30 126,30 126,30 151,30 151,30 151,30 151,30 176,20 176,20 176,20 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. C350 C300 C250 C200 C150 C120 C100 tnom mm 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 2,00 2,50 3,00 Iy cm4

Wy cm3

Iyeff cm4

Wyeff cm3

Iyeff cm4

Wyeff cm3

iy cm 3,918 3,918 3,917 3,915 4,647 4,647 4,646 4,642 5,700 5,702 5,703 5,696 7,787 7,784 7,783 7,778 9,528 9,524 9,523 9,517 11,524 11,527 11,521 11,519 13,219 13,215 13,211

Mb,Rd kNm 1,967 2,562 3,236 4,312 2,369 3,281 4,155 5,542 2,965 4,173 5,699 7,618 9,112 15,186 19,165 22,970 11,413 19,155 25,999 31,275 13,513 23,008 34,000 45,346 27,948 41,156 54,734

Mb,Rd kNm 1,948 2,578 3,236 4,312 2,354 3,264 4,155 5,542 2,991 4,162 5,659 7,618 9,107 14,944 19,165 22,970 11,441 18,716 25,698 31,275 13,573 23,051 33,585 43,906 27,980 40,654 53,066

2,03 2,45 3,08 4,13 2,22 2,68 3,37 4,52 2,52 3,04 3,82 5,13 5,50 7,38 9,25 11,13 6,23 8,36 10,48 12,61 7,52 10,08 12,65 15,21 11,20 14,05 16,90

1,22 1,72 2,42 3,64 1,22 1,71 2,43 3,67 1,22 1,72 2,44 3,74 2,77 4,67 6,56 8,56 2,75 4,63 6,55 8,59 2,63 4,57 6,85 9,19 4,75 7,09 9,51

31,155 37,607 47,262 63,289 47,935 57,866 72,727 97,403 81,872 98,841 124,239 166,423 333,533 447,103 560,349 673,275 565,589 758,256 950,410 1142,055 998,750 1339,303 1679,111 2018,181 1956,978 2453,684 2949,382

6,124 7,378 9,244 12,319 7,857 9,469 11,871 15,834 10,779 12,995 16,302 21,765 32,753 43,798 54,756 65,630 44,516 59,562 74,508 89,356 65,688 87,940 110,071 132,080 110,463 138,303 166,008

28,624 36,812 47,262 63,289 42,646 56,346 72,727 97,403 69,498 92,084 123,851 166,423 284,286 435,933 560,349 673,275 460,126 708,138 943,088 1142,055 704,848 1105,971 1533,544 1956,934 1587,383 2200,985 2807,307

5,620 7,321 9,244 12,319 6,768 9,374 11,871 15,834 8,471 11,923 16,283 21,765 26,036 43,388 54,756 65,630 32,610 54,727 74,282 89,356 38,607 65,738 97,143 129,561 79,851 117,588 156,384

29,432 37,566 47,262 63,289 43,793 57,392 72,727 97,403 71,579 94,238 123,716 166,423 291,220 440,601 560,349 673,275 470,892 714,300 942,613 1142,055 718,788 1127,403 1550,836 1956,195 1614,608 2221,387 2802,178

5,567 7,365 9,244 12,319 6,725 9,327 11,871 15,834 8,546 11,891 16,168 21,765 26,021 42,697 54,756 65,630 32,688 53,474 73,423 89,356 38,779 65,861 95,957 125,446 79,941 116,154 151,617

100

120

150

200

250

300

350

91,00 92,00

6

7

Lightweight purlin Sigma Steel grade: S350GD+Z Yield strength: fy = 350 MPa Tensile strength: fu = 420 MPa

Purlin Sigma Cross-section geometriesNo. Type of purlin Thickness Height Width of wide flange Width of narrow flange Fold Weight Cross-secti- Centre of Crossgravity on area, section effective area, gross Centre of gravity

Sleeve connection pieceHeight Width of wide flange Width of narrow flange

Purlin Sigma Cross-section characteristicsNo. Type of purlin Thickness Moment of inertia, gross Section modulus, gross Section Moment of modulus, inertia, effective/ effective/Top flange compres- Top flange compressed sed Moment of inertia, effective/ Bottom flange compressed Section modulus, effective/ Bottom flange compressed Radius of gyration Max. bending moment, in span/ Top flange compressed Max. bending moment, in span/ Bottom flange compressed

tnom mm 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. S400 S350 S300 S250 S200 S175 S150 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 2,00 2,50 3,00

H mm

A mm 72,00 72,00 72,00 72,00 72,00 72,00 72,00 72,00 72,00 72,00 72,00 72,00 80,00 80,00 80,00 80,00 80,00 80,00 80,00 80,00 80,00 80,00 80,00 80,00 80,00

B mm 64,00 64,00 64,00 64,00 64,00 64,00 64,00 64,00 64,00 64,00 64,00 64,00 70,00 70,00 70,00 70,00 70,00 70,00 70,00 70,00 70,00 70,00 70,00 70,00 70,00 70,00 70,00

C mm 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 25,00 25,00 25,00 25,00 25,00 25,00 25,00 25,00 25,00 25,00 25,00 25,00 25,00 25,00 25,00

g kg/m 4,12 5,50 6,87 8,24 4,59 6,12 7,65 9,18 4,95 6,59 8,24 9,89 5,71 7,61 9,52 11,42 5,95 7,93 9,91 11,89 6,89 9,18 11,48 13,78 9,81 12,27 14,72

Agross cm2 5,07 6,80 8,52 10,24 5,44 7,29 9,14 10,98 5,80 7,78 9,75 11,72 6,92 9,28 11,63 13,99 7,65 10,26 12,86 15,47 8,38 11,24 14,09 16,95 12,22 15,32 18,43

Aeff cm2 4,00 6,07 8,01 9,81 4,11 6,26 8,36 10,41 4,22 6,46 8,68 10,90 4,44 7,19 9,96 12,62 4,37 7,14 9,94 12,82 4,28 7,04 10,10 13,02 7,17 9,94 12,87

Yp mm 26,20 26,20 26,20 26,20 24,50 24,40 24,40 24,40 24,90 24,90 24,90 24,90 27,10 27,10 27,10 27,10 27,70 27,70 27,70 27,70 28,10 28,10 28,10 28,10 28,50 28,50 28,50

Zp mm 75,60 75,60 75,60 75,60 88,20 88,20 88,20 88,20 100,90 100,90 100,90 100,90 126,50 126,50 126,50 126,50 151,70 151,70 151,70 151,70 176,90 176,90 176,90 176,90 202,10 202,10 202,10

Hs mm 156,00 157,00 158,00 159,00 182,00 183,00 184,00 185,00 207,00 208,00 209,00 210,00 258,00 259,00 260,00 261,00 309,00 310,00 311,00 312,00 360,00 361,00 362,00 363,00 412,00 413,00 414,00

As mm 77,00 78,00 79,00 80,00 77,00 78,00 79,00 80,00 77,00 78,00 79,00 80,00 85,00 86,00 87,00 88,00 85,00 86,00 87,00 88,00 85,00 86,00 87,00 88,00 86,00 87,00 88,00

Bs mm 69,00 70,00 71,00 72,00 69,00 70,00 71,00 72,00 69,00 70,00 71,00 72,00 75,00 76,00 77,00 78,00 75,00 76,00 77,00 78,00 75,00 76,00 77,00 78,00 76,00 77,00 78,00 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. S400 S350 S300 S250 S200 S175 S150 tnom mm 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 1,50 2,00 2,50 3,00 2,00 2,50 3,00 Iy cm4

Wy cm3

Iyeff cm4

Wyeff cm3

Iyeff cm4

Wyeff cm3

iy cm 5,767 5,764 5,765 5,763 6,630 6,630 6,628 6,629 7,538 7,535 7,535 7,533 9,354 9,352 9,353 9,348 11,106 11,104 11,105 11,099 12,820 12,818 12,818 12,812 14,499 14,499 14,492

Mb,Rd kNm 6,704 10,090 12,843 15,442 8,100 12,128 15,601 18,795 9,755 14,522 18,801 22,660 13,466 20,475 27,406 33,148 17,244 26,153 34,964 42,947 21,246 32,235 43,121 53,062 38,260 51,899 63,869

Mb,Rd kNm 6,795 9,957 12,776 15,442 8,236 12,023 15,427 18,823 9,926 14,429 18,509 22,598 13,797 20,471 26,610 32,584 17,559 26,260 34,121 41,826 21,378 32,260 45,479 54,581 42,713 55,317 66,546

150

168,598 225,959 283,134 340,127 239,094 320,463 401,578 482,444 329,549 441,726 553,563 665,065 605,424 811,686 1017,409 1222,601 943,581 1265,137 1585,896 1905,863 1377,324 1846,805 2315,175 2782,443 2568,941 3220,625 3870,842

22,087 29,503 36,847 44,120 26,880 35,926 44,892 53,780 32,438 43,372 54,219 64,979 47,585 63,670 79,650 95,525 61,887 82,840 103,671 124,382 77,523 103,801 129,941 155,946 126,497 158,389 190,131

150,008 216,968 280,046 340,127 211,881 305,706 394,539 480,667 291,824 419,579 541,174 659,216 513,699 749,632 981,559 1197,862 794,212 1155,969 1513,136 1847,630 1152,197 1671,735 2188,893 2673,973 2296,135 3022,919 3693,448

19,155 28,829 36,695 44,120 23,144 34,653 44,575 53,701 27,871 41,490 53,716 64,744 38,474 58,501 78,304 94,708 49,268 74,724 99,896 122,706 60,702 92,100 123,204 151,606 109,316 148,283 182,483

155,180 220,847 281,477 340,127 219,280 311,428 396,924 482,444 301,866 427,556 544,796 662,366 534,527 768,115 987,291 1202,504 821,825 1185,418 1523,491 1856,851 1182,615 1710,631 2315,175 2782,443 2523,951 3217,718 3870,842

19,414 28,450 36,504 44,120 23,530 34,350 44,076 53,780 28,360 41,225 52,883 64,567 39,420 58,490 76,028 93,097 50,168 75,028 97,489 119,503 61,081 92,171 129,941 155,946 122,036 158,047 190,131

175

200

250

300

350

400

80,00 80,00

8

9

Lightweight purlin Hat Steel grade: S350GD+Z Yield strength: fy = 350 MPa Tensile strength: fu = 420 MPa

Purlin Hat Cross-section geometriesNo. Type of purlin Thickness Height Width of wide flange Width of narrow flange Fold Weight Crosssection area, gross Crosssection area, effective Centre of gravity Centre of gravity

Hat stengtheningHeight Width of wide flange Width of narrow flange

Purlin Hat Cross-section characteristicsNo. Type of purlin Thickness Moment of inertia, gross Section modulus, gross Moment of inertia, Section moduSection Moment of lus, effective/ effective/ modulus, effecinertia, Bottom flange Bottom flange effective/Top tive/Top flange compressed compressed compressed flange compressed Radius of gyration Max. bending moment, in span/Top flange compressed Max. bending moment, in span/ Bottom flange compressed

tnom mm 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. H250 H200 H150 H125 H100 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,50 2,00 2,50

H mm

A mm 100,00 100,00 100,00 100,00 100,00 100,00 100,00 100,00 100,00 100,00 100,00 100,00 120,00 120,00 120,00 120,00 120,00

B mm 40,00 40,00 40,00 40,00 40,00 40,00 40,00 40,00 40,00 40,00 40,00 40,00 50,00 50,00 50,00 50,00 50,00 50,00 50,00

C mm 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00 20,00

g kg/m 3,30 3,96 4,95 6,59 3,53 4,24 5,30 7,07 3,96 4,76 5,95 7,93 4,91 5,89 7,36 9,81 8,71 11,62 14,52

Agross cm2 3,88 4,68 5,89 7,90 4,36 5,26 6,62 8,88 4,84 5,84 7,35 9,86 6,18 7,47 9,39 12,60 10,84 14,54 18,24

Aeff cm2 2,07 2,92 4,19 6,49 2,08 2,94 4,25 6,64 2,08 2,95 4,27 6,74 2,06 2,97 4,49 7,24 4,49 7,27 10,53

Yp mm 87,80 87,80 87,70 87,80 87,70 87,70 87,80 87,80 87,80 87,70 87,70 87,70 107,70 107,70 107,80 107,70 107,70 107,80 107,80

Zp mm 48,40 48,40 48,40 48,40 60,60 60,60 60,60 60,60 72,80 72,80 72,90 72,90 97,60 97,60 97,60 97,60 122,10 122,10 122,10

Hj mm 98,00 98,00 98,00 98,00 122,50 122,50 122,50 122,50 147,00 147,00 147,00 147,00 196,00 196,00 196,00 196,00 245,00 245,00 245,00

Aj mm 95,00 94,60 94,00 93,00 95,00 94,60 94,00 93,00 95,00 94,60 94,00 93,00 115,00 114,60 114,00 113,00 114,00 113,00 112,00

Bj mm 44,00 44,40 45,00 46,00 44,00 44,40 45,00 46,00 44,00 44,40 45,00 46,00 54,00 54,40 55,00 56,00 55,00 56,00 57,00 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. H250 H200 H150 H125 H100 tnom mm 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,00 1,20 1,50 2,00 1,50 2,00 2,50 Iy cm4

Wy cm3

Iyeff cm4

Wyeff cm3

Iyeff cm4

Wyeff cm3

iy cm 3,943 3,945 3,943 3,941 4,832 4,834 4,832 4,829 5,693 5,695 5,693 5,690 7,544 7,540 7,542 7,539 9,167 9,165 9,161

Mb,Rd kNm 2,450 3,438 4,725 7,114 3,154 4,426 6,543 9,742 3,874 5,434 8,169 12,672 5,450 7,664 11,561 19,443 14,795 24,856 36,851

Mb,Rd kNm 4,063 5,031 6,307 8,413 5,120 6,775 8,501 11,351 6,174 8,491 10,915 14,585 8,231 11,668 17,099 24,607 21,356 32,309 42,161

100

60,335 72,847 91,580 122,708 101,802 122,920 154,541 207,093 156,877 189,429 238,175 319,200 351,697 424,734 534,141 716,093 910,835 1221,240 1530,882

11,926 14,373 18,020 24,036 16,057 19,361 24,289 32,432 20,602 24,848 31,187 41,673 34,683 41,848 52,558 70,306 71,923 96,264 120,460

42,427 56,592 75,817 110,196 69,610 93,007 129,979 187,502 104,222 139,504 197,198 291,019 205,782 277,455 395,640 614,696 645,489 1006,922 1403,338

7,000 9,823 13,499 20,325 9,011 12,645 18,695 27,834 11,069 15,527 23,341 36,206 15,573 21,898 33,031 55,550 42,272 71,017 105,289

58,246 72,689 91,580 122,708 94,749 122,203 154,541 207,093 140,991 183,702 238,175 319,200 273,435 365,979 504,780 716,093 817,855 1175,993 1530,882

11,607 14,374 18,020 24,036 14,629 19,358 24,289 32,432 17,640 24,261 31,187 41,673 23,518 33,336 48,855 70,306 61,016 92,312 120,460

125

150

200

250

120,00 120,00

10

11

2 Structural systemsThere are four alternative roof purlin systems for different applications, as well as various combinations of these systems. The properties of the systems and the selection criteria are discussed below. 2.1 Single span system Used in walls and roofs, in moderate spans Asimplesystem Samesupportreactionsofprimaryraftersincentrebays Smallnumberofjointcomponents Wholeroofconsistsofsimilarpurlins Higherconsumptionofsteel Higherdeflections CanbeimplementedwithZ,C,hatandsigmapurlins.

2.1.1 Single span system, purlin designation diagram

W SS

CantileverC_L

L W SI L

CantileverC_R

W SL

W SR L

CantileverC_L

L

CantileverC_R

N=Narrow flange up W=Wide flange up

Seen from eaves

Single span purlin (Cantilever Right) Inner bay SI

Single span purlin Left SL (Cantilever Left)

Single span purlin Inner bay (Cantilever Left) SI

Single span purlin Right SL (Cantilever Right)

Seen from eaves Upper flange toward ridge

Seen from eaves

Seen from eaves

12

13

2.1.2 Single span system, purlinsNote! On site the purlin is seen from the eavesW SS

2.1.3 Single span system, support cleatsN=Narrow flange up W=Wide flange up On site WIDE flange UP, ALL PURLINS Support cleat at end support Support cleat at end support

37 30 33

45 30 15

45 30 15

Z100100CantileverC_R

N100

90

CantileverC_L

L W SI L

HoleW SR L

= 14

W

90

U-80*35*4

U-120*35*425 70 25

W SL

CantileverC_L

37 50 33

L

CantileverC_R

45 50 15

45 50 15

W=Wide flange up

Note! Wide flange side in vertical design of pre-punching Reversed design to be used in reversed purlins Note! In manufacturing drawings the purlin is seen with the wide flange down and toward the reader

Z120Hole

120

120

110

= 14

W

110

N=Narrow flange up

N

U-80*35*4

U-120*35*425 70 25

50 30

50 30

L=span

48

N Z150Hole150 150

140

Pre-punched single span single purlin SS

= 14

W

52 50

60

140

U-80*35*4

U-120*35*425 70 25

48

N50 C_LCantilever

30

30

60

LPre-punched single span purlin, left end bay SL

50 C_RCantilever

200

190

100

190

Hole

= 18

W

52

100

Z200

200

100

U-80*35*4

U-120*35*425 70 25

60

48

30

250

240

150

240

Cantilever

60

Pre-punched single span purlin, inner bay SI

Hole

= 18

W

52

60

150

Z250

250

150

50 C_L

L-35 L

32 3

30

N

60

U-120*55*4

U-120*55*425 70 25

30

3 32

300

300

200

200

Z300Hole

290

290

200

L-70 LPre-punched single span purlin, right end bay

32 3

30

N

48

U-120*55*4

U-120*55*425 70 25

52

60

= 18

W N350 350

3 32

L-35 L

50 C_RCantilever

48

30

250

250

340

U-160*55*4

340

Z350Hole

250

30

60

U-160*55*445 70 45

= 18

W

52

60

14

15

60

2.2 Double span system

2.2.1 Double span system, purlin designation diagram

Double span single purlin CantileverC_L L_ L_

W DS L_ _R W DI L_R L_L_ L_ _R L_L

CantileverC_R

W DL

W DR L_R

CantileverC_L

L_L

CantileverC_R

Used in walls in 4-6m spans, and in roofs in moderate spans Smalldeflections Smallnumberofpartsrequiringinstallation Amountofinstallationworklimited Differentsupportreactionsofprincipalrafters Longsections,moredifficulttohandle CanbeimplementedwithZ,C,hatandsigmapurlins It is possible to use the same support cleat at intermediate support of each 2-span purlin as at purlin joint. A top hat purlin always has to be equipped with a brace section. The material thickness of this brace section is recommended to be the same as the material thickness of the purlin itself. The dimensions of the brace section are shown together with the cross-sectional dimensions of the top hat purlin, see section 1.6. LengthofbracesectionL>Max(3*s,2*H),wheresisthesupportwidthandHistheheightofthesection.


Seen from eaves

(Cantilever Right)

Double span purlin Right DR

Double span purlin Inner bay DI

Double span purlin Left DL

(Cantilever Left)

(Cantilever Left)

Double span purlin Left DL

Double span purlin Inner bay DI

Double span purlin Right DR

(Cantilever Right)

Seen from eaves Upper flange toward ridge

Seen from eaves

Seen from eaves

16

17

2.2.2 Double span system, purlins

2.2.3 Double span system, support cleatsN=Narrow flange up W=Wide flange up

Note! On site, the purlin is seen from the eaves

On site WIDE flange UP, ALL PURLINS

Support cleat at intermediate support

Support cleat at purlin joint

37 30 33

45 30 15

45 30 15

Z100100

N100

90

W DS

HoleL_R

= 14

W

90

U-80*35*4

U-120*35*425 70 25

CantileverC_L

L_L W DI

CantileverC_R

45 50 15

45 50 15

DL

DR L_R L_L L_R C_R

37 50 33

W

W

N Z120Hole120 120Cantilever

110

C_L

L_L

L_R

L_L



= 14

W

110

Cantilever

U-80*35*4

U-120*35*425 70 25

48

50 30

50 30

N150

60

60

L=span L_L=Left span length L_R=Right span length

Hole Pre-punched single span single purlin DS

= 14

W

52 50

Z150

150

140

140

U-80*35*4

U-120*35*425 70 25

48

30

30

N50 C_RCantilever

190

100

190

60

Hole

Cantilever

= 18

Pre-punched single span purlin, left end bay DL48 30 30

N50 C_LCantilever

60

50 C_L

L_L

L_R

W

52

100

Z200

200

U-80*35*4

U-120*35*425 70 25

200

100

L_LPre-punched single span purlin, inner bay DI

L_R-35 L_R

240

150

240

Hole

= 18

W

52

60

60

150

32 3

250

Z250

250

150

U-120*55*4

U-120*55*425 70 25

48

300

Pre-punched single span purlin, right end bay DR

Hole

= 18

W N

52

290

200

290

Z300

300

200

200

3 32

L_L-35 L_L

L_R-35 L_R

32 3

30

30

N

U-120*55*4

U-120*55*425 70 25

48

30

60

3 32

350

340

Cantilever

60

60

Hole

= 18

W

52

340

Z350

350

250

250

250

L_L-35 L_L

L_R

50 C_R

U-160*55*4

30

60

U-160*55*445 70 45

18

19

2.3 Sleeved system alternative design with Ruukkis PurCalc software

2.3.1 Sleeved system, purlin designation diagram

W VL NN VE L1

W VI VE L2

W VI NN VE L3

W VI VE L4

W VR

Cantilever

L5

N=Narrow flange up W=Wide flange up Seen from eaves

Sleeved system

Sleeved system Inner bay VI



Sleeved system Left end bay VL

Used in roof and wall structures System contains a special sleeve section, normally either similar gauge to basicpurlinormax.0.5mmthicker. Optimalweight Smalldeflections Sectionseasytohandle Alargernumberofcomponents Moreinstallationwork ForZsectionsthesleevesectionisidenticaltothebasicpurlinsection imensionsofsleevesectionareshowntogetherwiththecross-sectional D dimensions of the sigma purlin, see section 1.6.

Right end bay VR

Sleeved system Left end bay VL




Sleeved system Right end bay VR

Seen from eaves Upper flange towards ridge

Seen from eaves

Seen from eaves

20

21

2.3.2 Sleeved system, purlins

2.3.3 Sleeved system, support cleatsN=Narrow flange up W=Wide flange up On the site WIDE flange DOWN, SLEEVE SECTION VE On the site WIDE flange UP, ALL PURLINS Support cleat


33 30 37

37 30 33

45 30 15

Z100100W VI W VR VE L4 L5

N100

W100 100

W VL NN VE

W VI VE L2

W VI NN VE L3

= 14

W

N

90

U-120*35*425 70 25

Cantilever

L1

37 50 33

33 50 15

110



= 14

W

N

110

Z120

45 50 15

N120 120

W120

U-120*35*425 70 25

48

52

52 50

L=span L_L=Left span length L_R=Right span length L_tot= 0.13(L_L+L_R)+70

0,13L_L 0,13L_R

48

Sleeve section, VE

= 140,13L_R-35 35200

W

N

140

Z150

50 30

N150 150

W150 150

U-120*35*425 70 25

50

200

100

190

48

52

30

50 35

35

0,87L-35 LSleeved system, Inner bay, VI

0,13L-35 32 3

N Z250 = 18250 250

W250 250

60

Sleeved system, left end bay, VL

= 18

W

52

N

100

Z200

200

100

200

30

0,13L_L-35 35

70 L_tot

48

52

N

W

60

U-120*35*4

35 70 35

48

150

240

W

52

N

150

Cantilever

150

U-120*55*435 70 35

48

52

L300 200 300 300

30

3 32 0,13L-35

0,74L

0,13L-35 32 3

N Z300

W300

48

60

200

Sleeved system, right end bay, VR52

= 183 32 0,13L-35 0,87L-35 L 35 35 50350

W N

N W350 350

48

290

200

U-120*55*435 70 35

48

52

250

48

22

23

60

= 18

W

52

N

340

250

Z350

350

250

Cantilever

30

60

U-160*55*6

35 70 35

2.4 Overlapped system - recommended by Ruukki

2.4.1 Overlapped system, purlin designation diagram

N LL W LF L1 W LI L2

N LI WW LI L3 L4

N LR LF L5

Cantilever N=Narrow flange up W=Wide flange up Seen from eaves

Overlapped purlin

Overlapped purlin Inner bay LI



Overlapped purlin Left end bay LL

Used in roof and wall purlins, in spans of 6-10m The purlins are overlapped inside one another. A double purlin or a thicker section in end bay. Optimalweight Smalldeflections Longspanscanbeachieved Alargernumberofjoints Moreinstallationwork CanbeimplementedwithZsections

Right end bay LR

Overlapped purlin Left end bay LL




Overlapped purlin Right end bay LR

Seen from eaves Upper flange towards ridge

Seen from eaves

Seen from eaves

24

25

2.4.2 Overlapped system, purlins

2.4.3 Overlapped system, support cleatsN=Narrow flange up W=Wide flange up On the site WIDE flange DOWN On the site WIDE flange UP Support cleat

33 30 37


37 30 33

45 30 15

Z100100N LR WW LI LF L5 WW

N100

W100 100

N LL W LF W LI L1 L2

N LI

= 14

U-80*35*4

W

N

37 50 33

Cantilever

L3

L4

Cantilever

33 50 15

45 50 15

N120

W120 110

90

W=Wide flange up


= 14

W

N

48

52

50 30

L=span L_R=Right bay length

52 50

Overlapped reinforcement purlin LF, if required, in end fields

= 14

W

N

48

140

Z150

150

150

150

150

50

L_L=Left bay length

N

W

110

N=Narrow flange up

Z120

120

U-80*35*4

U-80*35*4

48

30

100

190

Overlapped purlin LL, left end bay

= 18

50Cantilever

0,8*L LOverlapped purlin LI, inner bay

0,07*L

0,13*L

0,2*L_R

48

50250

30

N Z250 = 18250

W250 250

52

60

W

52

N

48

100

Z200

200

200

200

100

200

50

0,8*L

50

N

W

52

60

U-80*35*4

150

150

240

W

N

52

50

0,13*L_L

0,13*L

0,07*L

0,6*L L

0,07*L

0,13*L

0,13*L_R

50300

300

300

200

30

N Z300 = 18300

W

48

52

48

60

150

U-120*55*4

52

48

W N350 350

N W350 350

50

0,2*L_L

48

52

0,13*L

0,07*L L

0,8*L

50Cantilever

30

60

Overlapped purlin LR, right end bay

290

200

U-120*55*4

200

250

250

Z350 = 18

52

48

340

W

N

26

27

60

250

U-160*55*6

2.5 Hole design principle for manufacture Standard pre-punching is used for each purlin system. The pre-punching dimensions are given with the lower flange towardtheviewerandthewiderflangeofthesectionasthe lowerflange.Thelongitudinallocationoftheholesisgiven as a distance from the cutting point, from left to right. The dimensioningofholesforfixingscrewsisstandardised. Pre-punchingisimplementedusingpunchesofdifferentsizes and forms. The selection of punches varies depending on the production plant and the section manufacturing method. The standardised sizes and locations of holes for fixing screws are presented below. Additional information about the pre-punching possibilities can be obtained by contacting us.

2.6 Types of holes Holes are made during production at continuous line information: - ax.materialthickness3mm m (for60mmmax.materialthickness2mm), - holes can be made in a row, - oval and rectangular holes can be rotated by 90.

Reference point for distances = cutting point

Type of hole

Diameter [mm]

Rotation

[mm] 7 10 12 14 16 18 Direction of steel band on the rolls A-wideflange B-narrowflange 20 22 26 60 1224 1424 1635 1831,7 1835 2035 525

[] 90 90 90 90 90 90 90

No limitation in number of holes during production.

28

29

2.7 Support cleats Purlin systems utilise support cleats attached to the primarybeamsofthebuildingframe.Thepurlinsarefixed to these support cleats from the web with screw joints. In Ruukki systems the support cleats are U sections made of at least steel grade S235. In the design of the support cleats, the tying of the section sheet on the roof ridge with a ridge moulding is taken into account. If a ridge moulding isnotused,thedimensioningoftheUsectionanditsfixing to the primary rafter must be separately checked due to the stresses caused by the load component acting in the direction of the roof slope. Whenscrewjointsareused,thesupportcleatsaredelivered with pre-drilled holes for hexagon screws, diameter either 14mm or 18mm depending on the size of the purlin. The sizes and the distances are shown in the purlin diagram. A sleeved system features two vertical rows of fixings, an overlapped system either one or two rows depending on selected support cleats. Single and double span systems have one or two rows, depending on the location of the support cleat and on the selection of support cleat. The program PurCalc for purlin dimensioning also determines therequirednumberoffixings. If self-drilling screws are to be used for some reason, the support cleat is not pre-drilled. However, it should be noted that screw joints must always be used if the material thickness of thepurlinexceeds1.5mm,duetojointductilityrequirements.

3 Factors to be considered in the use of lightweight purlins3.1 Torsional rigidity Lightweight purlins exhibit an open cross-section and low torsional rigidity in proportion to their bending rigidity. Due to the low torsional rigidity the lateral buckling resistance of an unsupported purlin restricts the load bearing capacity significantly. 3.2 Improving torsional rigidity Torsional rigidity can be improved by fixing the purlin to a form plate or corresponding that provides transverse support totheupperflangeofthepurlin.Thebendingrigidityofthe form plate also increases the rotational rigidity of the purlin. 3.3 Local buckling The resistance of a thin gauge sheet cross-section is restricted due to buckling of plate-like cross-sectional parts under compression, or by buckling under compression of plate-like stiffeners that resist buckling. A plane section does not loose its load bearing capacity completely; in fact, a plane section often retains a considerable part of its capacity in this state. This is modelled in calculations by removing a part under the most stress from the plane section, or by thinning the edge stiffener and the part of the plane section considered to be part of it. 3.4 Distortion of section In cross-sections of certain shapes, distortion of the section also restricts the load bearing capacity.

Examples of support cleats:

Flange edge stiffener thinned

Web section

C, Z and Sigma purlins are supported from their web to the primary rafter using the following U sections at low roof slopes, and when the section sheet is tied to the opposite slope sheet with a ridge moulding. Otherwise the fixing sections have to be dimensioned specifically for loads acting in the direction of the slope plane.

H< 200 300 350

U-Section U-80*35*4 U-120*55*4 U-160*55*6

30

31

3.5 Resistance to support reactions Buckling of the plane section is also possible in the support cleat, whereby the web of the purlin as a result of the support reaction tends to deviate from its plane, whichrestrictstheloadbearingcapacityofthepurlin.For reinforcement, a support cleat is normally used, e.g. a U sectionthatisfixedfromitsbacktothewebofthepurlinso that the support cleat alone transmits the support reaction to the rafter.

3.9 Unsupported lower flange under compression Incontinuouspurlinstheunsupportedlowerflangeofthepurlin is under compression at the brace moment, whereby it tends to buckle. This restricts the load bearing capacity of the purlin.

3.10 Cantilever purlin The load bearing capacity of cantilever purlins is low, but it canbeincreasedtosomeextentbyfixingthecantileverend rigidly to the face section.

3.6 Purlins that are supported at the flange Top hat purlins are always provided with a brace piece (cf. cross-sectionaldimensionsoftophatpurlins),whichisfixed togetherwiththebasicpurlinthroughitsflangesdirectlyto the primary rafter. The resistance to the support reactions is then produced by the top hat purlin and the brace section together. 3.7 Transverse rigidity The rigidity of thin gauge sheet purlins in the direction of theminoraxisislow.Thiscausesbendingattheroofslope plane, unless the slope has sheet rigidity. This could be the case,forexample,ifthesheetseamsfromtheridgetoward

the eaves are not fixed. However,it is recommended that the section sheets of the slopes are tied together with a ridge moulding. In practice, this will prevent the bending of the purlin in the direction of the roof slope, and at the same time essentially reduce the stresses acting on the support cleats. 3.8 Unsupported lower flange In single span purlins the unsupported lower flange of the purlin may be under compression due to wind uplift, whereby it can buckle in the transverse direction. This applies particularly to wall purlins, in which the self-weight of the structure does not counteract the suction pressure, as is the case in roof structure.

If distortion of the end of a cantilever purlin is prevented usinge.g.aUsectionofthesameheightasthepurlin,fixed from its flanges to the flanges of the cantilever purlin, the following shall be valid for the end support:

Otherwise the following shall be valid

Nsd /Aeff + M y, Sd /Weff, y 2M c, Rd , V/3Weff, yMinimum dimensions of the section that joins the free flangesofacantileverpurlin(upperflangesofthecantilever purlinareprovidedwithcontinuoussupportbyaformplate) Purlin height max150 max200 max300 max35033

Nsd /Aeff + My, Sd/Weff, y M c, Rd ,V/Weff, ywhere

Nsd Aeff

M y, Sd Weff, y M c, Rd , V

is the design value of normal force i s the effective area of the cross-section in axial compression is the design value of the moment with an end support is the effective bending resistance of the crosssectionagainstbendingabouttheyaxis is the bending resistance, when account is taken oftheinfluenceofshearforce

L-section 45*45-1.5 70*70-1.5 70*70-2.0 70*70-2.5

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4 PurCalc purlin design softwareDesign with PurCalc software enables the most economical solution for cold-formed purlin-based roof structure. The software includes Ruukkis offering of Z, Hat, Sigma and C purlins The options included in the software enables following calculations methods: - Calculation of purlin structure based on Eurocode, without purlin restrainment. - Calculation of purlins structure based on test results, whenpurlinsarerestrainedwithRuukkisprofilesheet - Calculation of purlin structure based on test results, when purlins are restrained by Ruukkis roof sandwich panels. Language options in the software are; Romanian, Hungarian, Slovak,Czech,PolishEnglish,SwedishandFinnish.

ensure the correct quantity and condition of the products. Thesuppliershallbeinformedinwritingofanydeficiencies and transport damages immediately. Damaged products are not allowed to install without Ruukkis approval. 5.3 Storage Materialsshouldbestoredasclosedaspossibletothefinal installation location indicated in the installation diagrams to avoid unnecessary liftings and transports. Purlins shall be stored in a dry place protected against rain and snow, on a level base. The dry storing conditions will prevent white rust on galvanised surface. Products shall be supported at regular intervals to prevent deformation. It is recommended that products are supported in a slightly inclinedposition(1:20),toensurethatpossiblewaterleaking onto the purlins will be drained. The packages should be raised above ground to allow ventilation of the bottom side of the packages. Materials should not be piled on top each other, as this may damage the sections. If purlins get wet in rain, they must be separated and dried toeliminatethepossibilityofwhiterust.Ifrequired,sufficient support shall be provided for the packages to prevent them from tipping or falling over.

The installation specification should contain at least the following information: projectdata designer installationtechnician materiallistandlayoutdiagram storageofcomponentsonsite handlingoftransportpackagesonsite installationequipment installationstages screwjoints temporarybracingduringinstallation installationtolerances qualificationofstructuresandqualitycontrol Structural parts must not be forced in place so that they are deformed or subjected to stresses. Thin gauge sheet structures are sensitive to local damage, and for this reason special attention shall be paid in installation to preventing the parts from being dented or otherwise damaged. Roof purlins do not usually require temporary bracing during installation,butthisshallbeverifiedwhenlongerspansor higher slopes are concerned. Z roof purlins shall always beinstalledwiththeupperflangetowardtheridge,cf.the Figure. In addition, the lower flange of a Z purlin must be installed at a distance of ca. 10 mm from the upper chord of the truss or the beam.

The work specification, the drawings, the installation plan and the quality control plan shall be studied before installation is started. The acceptance inspection of the materials, accessories, installation parts and lightweight purlins shall include an inspection of waybills, dispatch notes, transport damages and handling damages. It is important to verify that the materials and accessories comply with standards or aredeliveredwithcertifiedproductdeclarations. It is recommended that during installation, attention is paid to the following factors: locationofstructures straightnessofstructures angles jointsbetweencomponents maindimensions otherdimensions handling,liftingandstorageofmaterials,accessories and parts scaffolding tighteningandlockingofscrewsandnuts The installation sequence shall be determined before the purlins are installed. The bundles of purlins are lifted in the correct locations according to the installation diagram drawnupbythedesigner.Purlinswiththewideflangedown areinstalledfirst.

5 Handling, transport and storage of lightweight purlins5.1 Handling All necessary health and safety precautions have to be taken intoaccountwhenhandlingthepurlins.Whenhandlingthe products, it is recommended to use protective clothing and cut resistance gloves. When cutting the products, please use also respirator as cutting may release dust and small particles. Also special care shall always be exercised to prevent any damages to purlins itself. Even small dents and deflections may impair the load bearing capacity of the purlin significantly. Scratches on the zinc coating of the components be avoided. The materials shall be sufficiently protected against moisture and damages at various stages of their handling. If components are handled manually, appropriate protective gloves shall be worn to prevent injuries. 5.2 Transport Thepurlinsandthefixingcomponentsareattheproduction plant packed in packages that are easy to handle. Purlins are bundled together and small components are packed in separate packages. The content is clearly marked on each package to ensure they are transported to the correct site. On the site the materials should be carefully checked to

6 Installation of lightweight purlinsAll necessary health and safety precautions have to be taken intoaccountwhenhandlingthepurlins.Whenhandlingthe products, it is recommended to use protective clothing and cut resistance gloves. When cutting the products, please use also respirator as cutting may release dust and small particles. The installation of lightweight purlins is swift and easy. The purlinsareprimarilyfixedwithhexagonscrewjointsusing pre-drilled holes, or sometimes with self-drilling screws. It should be noted that purlins with a thickness of more than 1.5mmmustnotbefixedtosupportcleatsortoeachother withself-drillingscrews,buthexagonscrewjointsmustbe used. The low cost of installation is based on the swiftness of the work and on prefabricated structural parts. The small weight and the small space requirements of the structural parts reduce transport costs. Lightweight purlins are installed according to an installation diagram drawn up by the designer.

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Ruukki Lightweight Purlins Technical Manual

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