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
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.
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 www.wwpi.org 360-693-9958
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
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
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
Wood: The Real Renewable Building Product
Treated wood products are sustainable Inputs Seed Soil Water Sun CO 2 30-80 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
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
Durability Wood durability is threatened by: Carpenter ants Wood boring beetles Termites Decay fungi, rot Fire 10
Wood destroying insects Wood Boring Beetles Carpenter Ants Formosan Termite 11
Wood destroying insects Wood Boring Beetles $5 Billion Carpenter Ants Formosan Termite 12
Termite infestation probability Figure R301.2(6) International Residential Code 13
Hidden dangers of decay, rot 14
More moisture, more potential problems 15
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
Treated Wood Standards, Production
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
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
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
Pressure treating process Dried wood is loaded into retort, or pressure cylinder 21
Pressure treating process Retort is sealed, vacuum applied to remove air 22
Pressure treating process Pressure applied to infuse preservatives into wood 23
Pressure treating process Preservatives drained, returned to storage tanks 24
Pressure treating process Core samples taken to check for retention, penetration 25
Incising to achieve required penetration Incisor knives mounted on drums Lumber drawn through the drums 26
Preservatives: Oil-Type and Waterborne
Oil-type Preservatives Creosote Pentachlorophenol Copper Naphthenate 28
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
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
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
How safe are wood preservatives? 32
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
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
ACQ Alkaline Copper Quat Douglas Fir, Hem-Fir, Southern Yellow Pine AWPA, ICC-ES approved Ground and fresh water contact 35
ACZA Ammoniacal Copper Zinc Arsenate Douglas Fir, Southern Yellow Pine AWPA approved Ground, fresh and salt water contact 36
CA Copper Azole Douglas Fir, Hem-Fir, Southern Yellow Pine AWPA approved Ground and fresh water contact 37
MCA Micronized Copper Azole Douglas Fir, Hem-Fir, Southern Yellow Pine AWPA and ICC-ES approved Above ground, ground and fresh water contact 38
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
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
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
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
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
Reference for Preservatives PreserveTech: Preservatives Two-page reference sheet Covers common waterborne preservatives Available for download at PreservedWood.org in the Tech Library 44
Care and maintenance Waterborne treated products can be painted or stained Follow manufacturer s recommendations Water repellent coating recommended annually 45
Field treating End cuts for preserved woods MUST be field treated to meet code 46
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
Why field treat? Properly sealed end cuts prevent decay! 48
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
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
Treated Wood and Building Codes
International Building Code reference Section 2304.11 Decay and Termite Protection 52
International Building Code reference Section 2304.11.2 Wood used above ground, all uses 53
IBC Wood used above ground Section 2304.11.2.1 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
IBC Wood used above ground Section 2304.11.2.2 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
IBC Wood used above ground Section 2304.11.2.3 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
IBC Wood used above ground Section 2304.11.2.4 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
IBC Wood used above ground Section 2304.11.2.6 Wood siding, sheathing Wood siding, sheathing & wall framing on the exterior of a building having a clearance less than 6 to the ground. 58
IBC Wood used above ground Section 2304.11.2.7 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
IBC Wood used above ground Section 2304.11.3 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
IBC Wood in contact with ground, water Section 2304.11.4.1 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
IBC Wood in contact with ground, water Section 2304.11.4.2 Wood structural members Wood structural members supporting moisturepermeable floors or roofs that are exposed to weather such as concrete or masonry slabs. 62
IBC Exposed supporting members Section 2304.11.5 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
IBC Safety from wood-damaging insects Section 2304.11.6 Termite protection In geographical areas where hazard of termite damage is known to be very heavy, wood floor framing in locations specified in Section 2304.11.2.1 and exposed framing of exterior decks or balconies. 64
IBC Wood in contact with ground, water Section 2304.11.7 Wood used in retaining walls and cribs 65
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
Treated Wood Quality Marks, Fasteners
Product quality mark Section 2303.1.8.1 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
Product quality mark required information Proper exposure condition AWPA standard Preservative used Minimum retention Trademark of ALSC agency Identification of the treating plant 69
Fasteners with treated wood Section 2304.9.5 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
Reference for Fasteners PreserveTech: Fasteners One-page reference sheet Code requirements, recommendations listed Available for download at PreservedWood.org in the Tech Library 71
Specifying with the AWPA Use Category System
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
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
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
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
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
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
Use Category reference Specification Guide AWPA Use Category standards, retentions for specific products Available for download at PreservedWood.org 79
Use Category reference Infographic Approved by AWPA Additional information on UC3B, UC4A specification Available for download at PreservedWood.org 80
Treated Wood and the Environment
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
Life Cycle Assessments for treated wood ISO 14044 compliant Peer reviewed to confirm science, data Independently published in Journal of Cleaner Production and Marine Environmental Engineering 83
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
Reports available for review WWPI website: PreservedWood.org Treated Wood Council website: www.treated-wood.org 85
Handling and Disposal of Treated Wood
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
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
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 www.preservedwood.org 89
Thank You! Western Wood Preservers Institute www.wwpinstitute.org 360-693-9958 90
Questions? This concludes The American Institute of Architects Continuing Education Systems Course Kris Owen, Consultant Kowen4568@gmail.com For more information: Western Wood Preservers Institute PreservedWood.org 91