1. Wood Deterioration and its Prevention

7. 10 % of all wood cut in the U.S. replaces wood that has failed in service Wood Losses

8. Biotic vs Abiotic Abiotic: Non-living agents Heat: (>150 F)(Fire) hemicellulose>cellulose>lignin Chemicals: Strong bases, strong acids, salts Mechanical: impacts, erosion Sunlight: UV weathering attacks lignin

13. Biotic Agents  Fungi  Insects  Woodpeckers  Marine borers

14. Temperature Food Water Oxygen (air)

15. Biotic Requirements  Water (>20% MC but really 30 % or the fsp)  Moderate Temperature (32° to 100°F)  Oxygen  Food

16. Wood & Water 16 Occurs in two locations: Within cell lumen  Liquid  Called free water Within the cell wall  Captured in cell wall matrix  Called bound water Where is the Water in Wood? Liquid Free Water Cell Wall with Bound Water 8/20/2015

17. Wood & Water 17 Free water is liquid water that fills wood’s void spaces and affects only  Thermal conductivity  Mass Free Water 8/20/2015

18. Wood & Water 18 The Equilibrium Moisture Content (EMC) is the MC of wood when it is in equilibrium with the environment’s temperature and humidity. Equilibrium Moisture Content From Haygreen & Bowyer (1989) 8/20/2015

19. Wood & Water 19 Temp. °F Relative Humidity % 30%60%90% 30°6.311.321.0 70°6.211.020.5 90°5.910.519.8 130°5.29.418.2 EMC of wood at various temperature and humidity values Temperature & Humidity 8/20/2015

21. Bacteria Remove pit membranes Degrade extractives Digest cell walls (Tunneling) Can be important in submerged wood

22. Fungi

23. Fungal Spores are Everywhere

24. Fungal Types Molds/Stain Fungi Soft rot fungi Brown rot fungi White rot fungi

25. Green Fungal Hyphae in Wood

26. Blue Stain http://www.forestry.ubc.ca/brchline/98sept/page4.html

27. Mold on sapwood

28. Mold Species 250 to 300,000 species 45 species on Douglas-fir sapwood lumber in the first 6 weeks

29. Decay Fungus Fruiting Body

30. Brown Rot

31. White Rot

32. Damage by True Dry rot Fungus

34. Example of Decay Fungus in Culture

35. Soft Rot on a Utility Pole

36. Southern pine

37. Southern pine with soft rot

38. Soft Rot on a Eucalyptus pole

39. Decay Effects Reduced bending strength Reduced acoustic/insulation value Increased permeability Increased water absorption

41. Wood Destroying Insects Carpenter ants Termites Beetles Bark/Ambrosia Metallic wood borers Long-horned borers Powderpost beetles

42. Carpenter Ants Social insects (Queen/workers) Use wood for shelter Forage for food outside nest Attack softer woods Colonies <100,000 workers

43. Carpenter ant Worker

44. Carpenter ant Frass

45. Carpenter Ant Damage

46. Termites  Social Insects  Types  Subterranean  Wet wood  Dry wood  Light colored, small to large insect  Straight antenna  Unrestricted waist  Reproductives have wings of equal length

47. Dampwood termites Require very wet wood Colonies small (several thousand workers) Confined to Pacific NW and Florida)

48. Dampwood Termites

49. Subterranean Termites Require soil contact Large colonies (1 to 5 million) Produce mud-tubes

50. Subterranean termite Workers

51. Termite mud-tube up concrete wall

52. Wood Deterioration Wood destroying Insects Termites http://www.utoronto.ca/forest/termite/ter mite.htm. http://www.utoronto.ca/forest/termite/termite.htm http://www.utoronto.ca/forest/termite/micqueen.htm

53. Drywood Termites Attack very dry wood (<13 % MC) Confined to Pacific SW Attack wood above ground

54. Wood Deterioration Wood destroying Insects Termite Damage http://www.longpestcontrol.com/termites.html http://www.ent.orst.edu/urban/Termites.html http://www.utoronto.ca/forest/termite/ret_dam.htm

55. Termite vs Carpenter Ant Reproductives

56. Beetles-Coleoptera Bark beetles Ambrosia beetles Long horned beetles Metallic wood borers Powderpost beetles

57. Wood Deterioration Wood destroying Insects Ambrosia Beetle

58. Wood Deterioration Wood destroying Insects Ambrosia Beetle Damage in a Peeler Core

60. Beetles-Coleoptera Golden buprestid  Eggs deposited in green wood  Adults leave elliptical holes when they emerge  Very long life cycle

61. Buprestid gallery with decay

62. Beetles-Coleoptera Long horned Borers Have long antennae Larva produce round tunnels Most have 1-2 year life cycles Most do not attack finished wood farm4.static.flickr.com/3113/2847107680_8e229

64. Powderpost Beetles  Attack dry sapwood  Especially destructive to museum pieces or seldom used furniture  Evidenced by fine powder and small emergence holes http://www.cfr.washington.edu/classes.fm.324/images/ins ect_galleries/dcp00044.jpg http://www.ces.ncsu.edu/depts/ent/notes/Urban/ppb-wif.htm

67. Woodpeckers Excavate galleries to find insects (ants, beetle larvae), create roosts, and nests Damage opens wood to water, fungi and insects www.wunderground.com/.../n/NorthLight/284.jpg

69. Woodpecker Damage

72. Marine Borers Require Salt water Types  Shipworms (Teredo/Bankia)  Limnoria (gribbles)  Pholads

73. Shipworms (Teredo)  Mollusks  Larva borrow into wood leaving only very small entrance hole  Filter feed through entrance hole  Can reach ¾“ diameter hole that is 1-5 feet long http://bioweb.uwlax.edu/zoolab/Table_of_Contents/L ab ‑ 05/Shipworms_1/shipworms_1.htm http://bioweb.uwlax.edu/zoolab/Table_of_Contents/Lab ‑ 05/Ship worms_1/Shipworms_1a/shipworms_1a.htm

74. Shipworm Head

75. Internal Shipworm Damage

76. X-ray of wood showing shipworm tunnels

77. Pholads Mollusks  ¼“ entrance hole  Grows 1-2.5 inch diameter  Weakens pilings outer shell  Tend to be more tropical http://membres.lycos.fr/mattauer0001/rivage2.jpg

78. Pholads

79. Limnoria (Gribbles)  Small crustacean  Live in surface borrows for protection  Wave action erodes weakened wood- producing an hourglass shape  Can attack even creosote treated wood http://www.ffp.csiro.au/wft/wpc/fig1_2.jpg

80. Limnoria damage at tide line

81. Preventing Deterioration

89. Building Issues -Less air circulation -Less durable materials -Changes in design -HVAC Systems -Indoor plumbing

90. Prevention Methods Keep wood dry Coat wood Alter wood/moisture relationships Poison wood (natural or artificial)

91. Keep Wood Dry Avoid soil contact Long roof overhangs Gutters Caulking and paint Ventilation Remove vegetation

92. Durable Heartwoods

93. Natural Durability Heartwood only Varies with age and height Varies from tree to tree Second growth can have reduced decay resistance

94. Artificial Protection Fire protection Water repellency UV protection Improve physical properties Improve appearance Biological protection

98. Protection Strategies Create barriers Chemically alter substrate Bulk cells to alter wood/moisture relationship Apply toxins

99. Wood Orientation

100. Sapwood is more permeable

101. Non-Traditional Modification Thermal Treatment Bulking (glycol) Smoking Silanes

102. Barrier Treatments Metal, concrete, plastic, or fiberglass coatings Paint films Water repellents

105. Wood Bulking Polyethylene glycol Silanes Resins/Methacrylates Waxes

107. Treat Wood End Tag

108. Preservatives Creosote* Pentachlorophenol* Inorganic arsenicals* Copper/organic biocides Totally carbon based

110. Goal of Treatment Create a shell of protection sufficient to support a design load or a barrier that protects the interior

116. Wood Protection Myths Charring protects Salt protects Silanes protect Harvesting time matters Coatings completely protect

117. Reality Wood has high energy and many organisms have evolved to utilize it. Unless you deny a requirement or alter the substrate, something will eventually attack.