Preservative-Treated Wood: Use and Specification

Transcription

1 Preservative-Treated Wood: Use and Specification Presented by Kris Owen, Consultant Prepared by Western Wood Preservers Institute Disclaimer: This presentation was developed by a third party and is not funded by WoodWorks or the Softwood Lumber Board

2 The Wood Products Council is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES), Provider #G516. Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This course is registered with AIA CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 Copyright This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written permission from WWPI is prohibited. Western Wood Preservers Institute 2018 Western Wood Preservers Institute

4 Course Description In applications where wood may be exposed to moisture, insects or fungal organisms, preservative-treated wood can help ensure a building s durability. In this presentation, participants will learn about the manufacturing process for pressure-treated wood, available products and their differences, and how preserved wood is used in construction. Topics will include types of preservative treatments and the required levels of retention, as dictated by the end-use application, desired service life and exposure conditions. AWPA Use Category standards and ICC-ES Report Evaluations will be reviewed, and current issues concerning treated wood in non-residential and multi-family construction be discussed. 4

5 Learning Objectives Learn how to specify pressure treated wood products using the American Wood Protection Association's Use Category System. Learn where pressure treated wood is required under the Building Code. Develop an understanding of the AWPA Use Specification Guide, and a list of resources where they can find more information on pressure treated wood. 5

6 Western Wood Preservers Institute Represents preservative treated wood producers, chemical manufacturers and others serving the industry throughout western North America Mission Increase awareness of the proper use of treated wood products by providing information to: Owners Builders Architects, Specifiers Bldg. Material Dealers Code Officials Ports and Marinas 6

7 Wood: The Real Renewable Building Product

8 Treated wood products are sustainable Inputs Seed Soil Water Sun CO years of forest management Outputs Oxygen Habitat Stored Carbon Mature Forest Wood Products By the time your treated product has served its life, a new one will be grown and ready to replace it 8

9 Common uses of preservative treated wood in non-residential buildings Framing members on foundation or in direct contact with concrete (wood frame over podium) Wood used in balconies, porches, etc. exposed to weather 9

10 Durability Wood durability is threatened by: Carpenter ants Wood boring beetles Termites Decay fungi, rot Fire 10

11 Wood destroying insects Wood Boring Beetles Carpenter Ants Formosan Termite 11

12 Wood destroying insects Wood Boring Beetles $5 Billion Carpenter Ants Formosan Termite 12

13 Termite infestation probability Figure R301.2(6) International Residential Code 13

14 Hidden dangers of decay, rot 14

15 More moisture, more potential problems 15

16 Solution Pressure treat wood with preservatives Extends service life of wood to decades Maintains reliable physical, mechanical properties Readily available, safe to work with, cost effective 16

17 Treated Wood Standards, Production

18 American Wood Protection Association Founded in 1904 Standards writing organization for the U.S. wood preserving industry Provides technical forum for industry, research, users Referenced in all building codes Updated annually 2017 edition now available 18

19 AWPA s role in the treating industry Determines if a preservative is effective and can be listed in the standards Established how much preservative is needed (retention) depending on exposure, use Industry seeking to minimize chemical use through lower retentions 19

20 Who determines if preservatives are safe? All wood preservatives must be registered U.S. Environmental Protection Agency (EPA) Detailed risk reviews for human health, environmental impacts Product labels designate in where treated wood can be used in construction 20

21 Pressure treating process Dried wood is loaded into retort, or pressure cylinder 21

22 Pressure treating process Retort is sealed, vacuum applied to remove air 22

23 Pressure treating process Pressure applied to infuse preservatives into wood 23

24 Pressure treating process Preservatives drained, returned to storage tanks 24

25 Pressure treating process Core samples taken to check for retention, penetration 25

26 Incising to achieve required penetration Incisor knives mounted on drums Lumber drawn through the drums 26

27 Preservatives: Oil-Type and Waterborne

28 Oil-type Preservatives Creosote Pentachlorophenol Copper Naphthenate 28

29 Creosote One of the first preservatives used Railroad ties, utility poles, pilings, docks, guard rail posts, bridge timbers AWPA approved Ground contact and fresh/salt water immersion 29

30 Pentachlorophenol In use since 1930s Utility poles, crossarms, pilings, timbers, bridge decking, guard rails Est. 80%+ of utility poles treated with penta AWPA approved Ground and fresh water contact 30

31 Copper Naphthenate AWPA approved preservative for field treatment Utility poles, crossarms, posts, bridge timbers, decking Above ground, ground and fresh water contact Not listed by EPA as a restricted use pesticide 31

32 How safe are wood preservatives? 32

33 Regional product differences Western species Douglas Fir, Hem-Fir, Pines WWPI members produce only products listed in the AWPA Standards Southern species Southern Yellow Pine SYP production includes products listed in AWPA Standards or ICC Evaluation Service criteria All treated products inspected by accredited agency 33

34 Waterborne Preservatives AWPA approved ACQ Alkaline Copper Quat ACZA (Chemonite) Ammoniacal Copper Zinc Arsenate CA Copper Azole MCA Micronized Copper Azole CCA Chromated Copper Arsenate SBX Inorganic Boron PTI and EL 2 Carbon-based preservatives 34

35 ACQ Alkaline Copper Quat Douglas Fir, Hem-Fir, Southern Yellow Pine AWPA, ICC-ES approved Ground and fresh water contact 35

36 ACZA Ammoniacal Copper Zinc Arsenate Douglas Fir, Southern Yellow Pine AWPA approved Ground, fresh and salt water contact 36

37 CA Copper Azole Douglas Fir, Hem-Fir, Southern Yellow Pine AWPA approved Ground and fresh water contact 37

38 MCA Micronized Copper Azole Douglas Fir, Hem-Fir, Southern Yellow Pine AWPA and ICC-ES approved Above ground, ground and fresh water contact 38

39 CCA Chromated Copper Arsenate Used since the 1940s Douglas Fir, Hem-Fir, Southern Yellow Pine AWPA approved Ground contact and fresh/salt water immersion 39

40 CCA Chromated Copper Arsenate Industry voluntarily modified EPA registered uses for CCA Since 2003, CCA not available for consumer, residential applications CCA approved for industrial use: plywood, highway construction, utility poles, piling, agriculture EPA does NOT recommend removal of existing CCA structures 40

41 SBX Inorganic Boron Douglas Fir, Hem-Fir, Southern Yellow Pine AWPA approved AWPA C-31 Where its application is continually protected from liquid water. Sill plate, interior framing applications 41

42 PTI Carbon-based preservative Douglas Fir, Hem-Fir, Southern Yellow Pine AWPA, ICC-ES approved Above ground use only Low impact on hardware, coatings 42

43 EL2 Carbon-based preservative Douglas Fir, Hem-Fir, Southern Yellow Pine AWPA, ICC-ES approved Above ground use only Low impact on hardware, coatings 43

44 Reference for Preservatives PreserveTech: Preservatives Two-page reference sheet Covers common waterborne preservatives Available for download at PreservedWood.org in the Tech Library 44

45 Care and maintenance Waterborne treated products can be painted or stained Follow manufacturer s recommendations Water repellent coating recommended annually 45

46 Field treating End cuts for preserved woods MUST be field treated to meet code 46

47 International Building Code requirements Cut ends, notches and drilled holes of preservative treated wood shall be treated in the field in accordance with AWPA M4 47

48 Why field treat? Properly sealed end cuts prevent decay! 48

49 Field treatments Available field treatment products Tenino Copper Naphthenate (2% oil based) QNAP 2 Copper Naphthenate RTU (2% oil based) Copper-Green Brown Preservative (1% oil based) Copper-Green Preservative (1% oil based) Woodlife CopperCoat (1% water based) Photo courtesy of Poles, Inc. 49

50 Reference for Field Treating PreserveTech: Field Treating One-page reference sheet Code requirements, recommended treatments Available for download at PreservedWood.org in the Tech Library 50

51 Treated Wood and Building Codes

52 International Building Code reference Section Decay and Termite Protection 52

53 International Building Code reference Section Wood used above ground, all uses 53

54 IBC Wood used above ground Section Joists, girders and subfloor Wood joists or the bottom of a wood structural floor closer than 18 or wood girders when closer than 12 to exposed ground in crawl spaces or unexcavated areas located within the periphery of the building foundation. 54

55 IBC Wood used above ground Section Wood supported by exterior foundation walls Wood framing members that rest on concrete or masonry exterior foundation walls & are less than 8 from exposed ground. 55

56 IBC Wood used above ground Section Exterior walls below grade Wood furring strips or other wood framing members attached to the interior or exterior masonry or concrete walls below grade. 56

57 IBC Wood used above ground Section Sills and sleepers All foundation plates or sills and sleepers on a concrete or masonry slab, which is in direct contact with earth, and sill which rest on concrete or masonry foundations. 57

58 IBC Wood used above ground Section Wood siding, sheathing Wood siding, sheathing & wall framing on the exterior of a building having a clearance less than 6 to the ground. 58

59 IBC Wood used above ground Section Posts or columns Posts or columns supporting permanent structures and supported by a concrete or masonry slab or footing that is in direct contact with the earth. 59

60 IBC Wood used above ground Section Laminated timbers The portions of glued laminated timbers that form the structural supports of a building and are exposed to weather and not protected from moisture. 60

61 IBC Wood in contact with ground, water Section Posts or columns Posts and columns supporting permanent structures that are embedded in concrete that is in direct contact with the earth, embedded in concrete that is exposed to the weather, or in direct contact with the earth. 61

62 IBC Wood in contact with ground, water Section Wood structural members Wood structural members supporting moisturepermeable floors or roofs that are exposed to weather such as concrete or masonry slabs. 62

63 IBC Exposed supporting members Section Supporting member for permanent appurtenances In geographical areas where needed, wood members which support buildings, balconies, decks or porches if exposed to weather and without adequate cover protection. 63

64 IBC Safety from wood-damaging insects Section Termite protection In geographical areas where hazard of termite damage is known to be very heavy, wood floor framing in locations specified in Section and exposed framing of exterior decks or balconies. 64

65 IBC Wood in contact with ground, water Section Wood used in retaining walls and cribs 65

66 Reference for Codes Preserved Wood and 2015 IBC Covers current code references for preserved wood in construction Available for download at PreservedWood.org in the Tech Library 66

67 Treated Wood Quality Marks, Fasteners

68 Product quality mark Section All preservative-treated wood shall bear the quality mark of an inspection agency which has been accredited by the American Lumber Standards Committee and complies with the requirements of the ALSC Treated Wood Program or equivalent. 68

69 Product quality mark required information Proper exposure condition AWPA standard Preservative used Minimum retention Trademark of ALSC agency Identification of the treating plant 69

70 Fasteners with treated wood Section Fasteners, including nuts and washers, in contact with preservative-treated wood shall be of hot-dipped zinccoated galvanized steel, stainless steel, silicon bronze or copper Exception: Plain carbon steel fasteners in SBX/DOT and zinc borate preservative-treated wood in an interior, dry environment shall be permitted 70

71 Reference for Fasteners PreserveTech: Fasteners One-page reference sheet Code requirements, recommendations listed Available for download at PreservedWood.org in the Tech Library 71

72 Specifying with the AWPA Use Category System

73 AWPA Use Categories Based on end use biodeterioration hazard Five Use Categories based on exposures, expected performance Categories range from weather protected (UC1 mild exposure/lowest risk) to salt water marine (UC5 severe exposure/highest risk) 73

74 Use Category 1 UC1 Interior construction Not in contact with ground or foundations Protected from weather Protected from interior sources of water Insect hazard only 74

75 Use Category 2 UC2 Interior construction Not in contact with ground or foundations Protected from weather Subject to dampness and occasional sources of water Decay fungi and insect hazard 75

76 Use Category 3 UC3 Above ground, exposed to weather UC3A: Coated and rapid water runoff UC3B: Uncoated or poor water runoff Decay fungi and insect hazard 76

77 Use Category 4 UC4 Ground or fresh water contact, exposed to weather UC4A: Deck supports UC4B: Foundation, building poles Decay fungi and insect hazard 77

78 Specifying UC3B or UC4A AWPA standards revised in 2016 Addresses above ground uses where wood exposed to ground contact hazards UC4A for wood components used above ground but are difficult to maintain, repair or replace and are critical to the performance and safety of the entire system/construction Specific conditions listed in standards 78

79 Use Category reference Specification Guide AWPA Use Category standards, retentions for specific products Available for download at PreservedWood.org 79

80 Use Category reference Infographic Approved by AWPA Additional information on UC3B, UC4A specification Available for download at PreservedWood.org 80

81 Treated Wood and the Environment

82 Life Cycle Assessments for treated wood Borate-treated lumber compared to galvanized steel ACQ-treated lumber compared to plastic composite decking Marine pilings compared to steel, concrete, plastic 82

83 Life Cycle Assessments for treated wood ISO compliant Peer reviewed to confirm science, data Independently published in Journal of Cleaner Production and Marine Environmental Engineering 83

84 LCA conclusions Preserved wood products have significantly lower impacts than alternatives Wood uses less energy, water and fossil fuels with lower environmental impacts Composite of 7 environmental indicators, normalized 84

85 Reports available for review WWPI website: PreservedWood.org Treated Wood Council website: 85

86 Handling and Disposal of Treated Wood

87 Safe use of treated wood Precautions for treated wood same as for nontreated wood Avoid frequent or prolonged exposure to sawdust; dusk mask recommended Consumer info sheets, SDS available from manufacturers 87

88 Disposal of treated wood Reusing treated wood is preferred option Do not mulch Do not burn, unless in commercial or industrial incinerators Not considered hazardous waste, can be disposed at a landfill 88

89 Any time. Any where. Treated Wood Guide app Free download available for ios and Android Key information needed to understand, properly specify treated wood Search Treated Wood Guide in online stores 89

90 Thank You! Western Wood Preservers Institute

91 Questions? This concludes The American Institute of Architects Continuing Education Systems Course Kris Owen, Consultant For more information: Western Wood Preservers Institute PreservedWood.org 91