1 Deterioration of Trusses and Roof Systems of Livestock Farm Buildings By Yves Choinière Ing., agr., P. Eng. CSBE:

2 Introduction Deterioration of steel and wood components of farm building – Well known – Documented

3 Case study #1: Finishing swine barn, Ontario – Power-natural ventilation versus 100 % natural ventilation #2: Nursery-finishing, Ontario – Mechanical ventilation #3: Finishing swine barn, Quebec – 100 % natural ventilation #4: Pullet rearing barn – Mechanical ventilation

4 Case #1: Finishing swine barn

5 Barn A – Power-natural ventilation, 1996 – Winter pit fans – Modular ceiling air inlets – Deep pit over slatted floor – Summer natural ventilation Barn B – 100 % natural ventilation, 1995 – Similar to barn A

6

7

8

9

10

11

12

13

14

15

16

17 Table of results, power-natural 1996 November 21, 2007 Exterior T° = 5°C, rain Attic measurementsIn-barn T°6-7° C15-16° C R.H. %60-65 %80-85 % NH ppm15 ppm CO ppm3 000 ppm

18 Table of results, 100 % natural 1996 Attic measurementsIn-barn T°6-7° C15-16° C R.H. %70-75 %70 % NH 3 N\D15 ppm CO ppm3 000 ppm

19

20

21

22

23

24

25

26 Observations Attic space contamination from the barn to the attic by : – Modular air inlets – Fan exhaust – Eave openings – Vapor barrier failure

27 Case #2: Nursery-finishing barn

28 Case #2: Nursery-finishing Mechanical ventilation – Ceiling modular air inlets – Sidewall fans – Open eave

29

30

31

32

33

34

35 Table of results, Attic measurementsIn-barn T°7-8° C21-22° C R.H. %75-80 %70-75 % NH ppm16-17 ppm CO ppm ppm

36 Observations Attic space contamination : – Modular air inlets – Fan exhaust – Eave openings – Vapor barrier failure

37 Case #3: Finishing swine naturally ventilated barn Natural ventilation – Alley scrappers – Eave openings – Attic ventilation

38

39

40

41

42

43

44

45 Observations Eave opening desing; minimum space Vapor barrier Chimney vapor tightness Ridge ventilator, snow + rain

46 Case #4: Pullet rearing barn, 1976 Sidewall air inlets without attic contact Sidewall fan exhaust with wind stoppers

47

48

49

50

51

52

53

54 Conclusion Ceiling modular air inlets – Risk of attic backdraft – Sealed or negative pressure Sidewall exhaust fans – No eave openings above winter fans – Fans with winter hoods – Eave opening desing

55 Conclusion Attic ventilation – Ridge ventilator – Eave openings, winter and summer – Fire stops

56 Aknowledgements Greg Zimmer, Ontario André Lafrance, Quebec VicWest steel products