Selection & Specification Guide. Preservative Treatments for Timber & Wood Products in New Zealand

Transcription

1 Selection & Specification Guide Preservative Treatments for Timber & Wood Products in New Zealand

2 Purpose This document is designed to assist producers, resellers, specifiers and end-users of preservative treated wood products to better understand the appropriate application of industrial wood preservatives for various types of wood products and correct selection and specification of preservative treatment for various end-use situations. Industrial wood preservatives from Lonza are only for use in suitably constructed and authorized industrial wood treatment facilities and are not available for use by consumers or the end-user. Tanalised Wood Products The Case for Built-In Durability Wood is a versatile construction material that has many benefits over alternative materials with regard to net environmental impact, cost effectiveness and ease of use. It is the only significant building material whose production and use can result in a net positive carbon storage balance as the wood fibre is created by photosynthesis where growing trees absorb atmospheric carbon dioxide. Managed plantation forestry is the most sustainable way to produce wood fibre for manufacture of timber and wood products. New Zealand has a strong plantation forestry sector mainly utilising exotic species such as Radiata pine among others. New Zealand also has a modern and efficient wood processing industry to convert this plentiful resource into a wide range of useful building and other products for domestic and export markets. Durability and reliability in service are the key considerations in determining the suitability of building materials along with good design and construction practices to ensure a resilient and sustainable built environment. In many applications timber and wood products require protection from natural biological agents such as mould, decay and insects. The best way of ensuring the durability of timber and wood products is by industrial pre-treatment incorporating a Lonza preservative in accordance with New Zealand, Australian or other recognised standards. Lonza works with leading wood processors and manufacturers in New Zealand and around the world to improve the durability and serviceability of wood products using our chemical and related technologies. Tanalised has been the traditional treatment brand in New Zealand for hardworking rural and outdoor wood products since the 1940 s. These days there are many more protection options available from Lonza for the current generation of wood products. Lonza and our customers take pride in ensuring that treated wood and timber products incorporating our chemistry are produced in environmentally compliant facilities, safe to use, fit for purpose and supplied in conformance with relevant standards. We hope that you find this guide useful and please feel free contact us for additional information.

3 Boron-based Preservatives Framebor N Framebor N is a H1.2 boron based framing treatment solution using a novel patented boron formulation which provides significant processing improvements compared to most other boron preservatives. Our boron formulation and treatment process results in a minimal moisture content increase in the treated timber. Because the solution has a lower conductivity and is less hygroscopic than some borate formulations, moisture content readings with conductivity meters is closer to true MC%. To keep the wood clean during pre-construction it also incorporates an effective mouldicide. Ideal for treatment of kiln dried stress graded timber with low uptake Lowry or Reuping type treatment processes. Framebor N wood preservative is applied with proprietary pressure and vacuum impregnation processes developed by Lonza to ensure that the NZS3640 H1.2 requirements for preservative penetration and retention are met. Uses: H1.2 as per NZS all interior timber construction where not directly exposed to weather wall framing, sub-floor framing, roof framing. See NZS3602 for further details. Fasteners: The Framebor treatment itself is not corrosive to steel. Normal bright steel nails and connectors are suitable. H1.2 treatments normally incorporate a red or pink colouring dye for easy identification of the treated wood. Painting: H1.2 treated timber is not normally painted. If painting is required, use of a stain blocking primer is recommended to prevent bleed through of the red colouring dye. Pre-construction exposure: Boron based preservatives are not fixed in the timber and can be leached out under long term exposure to rain or ground contact. Exposure to weather prior to and during construction should be minimized (<3 months) to ensure compliance with treatment requirements in the finished structure. Do not store the timber directly on the ground. If H1.2 treated timber is exposed for more than 3 months re-testing of affected sections may be required by the relevant territorial authority to ensure that the timber is still compliant. Timber species: Radiata pine, New Zealand Douglas fir. Other timber species may be approved on testing and verification. Specified treatments for timber framing (Radiata pine or Douglas fir) as per the New Zealand Building Code. ENCLOSED BALCONY supported by posts and beams ENCLOSED BALCONY with balustrades in open and closed areas, roof decks and base plates ENCLOSED BALCONY with cantilever and balustrade KEY H1.2 H3.2 H5 Diagrams used courtesy of the Ministry of Business, Innovation and Employment. See Building Code Compliance Document B2 Durability for full details.

4 Diffusol Diffusol is a traditional boron based preservative intended for application to sawn timber by pressure treatment or dip diffusion to meet NZS3640 requirements for hazard class H1.2. Diffusol wood preservative may also be used to treat hardwood timbers to hazard class H1 under AS for immunization against beetle borers. Contact Lonza for further details. Uses: H1.2 as per NZS340 - all interior timber construction where not directly exposed to weather wall framing, sub-floor framing, roof framing. See NZS3602 for further details. Timber species: Radiata pine, New Zealand Douglas fir. Lyctus susceptible hardwoods such as certain eucalyptus species and shorea spp (Meranti). Fasteners: The Diffusol treatment itself is not corrosive to steel. Normal bright steel nails and connectors are suitable Diffusol wood preservative can be applied with dip, spray or pressure treatment processes. Lonza can advise on the details of the various treatment processes and solution concentrations appropriate for different types of wood commodities. H1 as per AS lyctus borer immunization of susceptible hardwoods Engineered Wood Products With the acquisition of Zelam, Lonza is now able to offer glue line additive treatments (GLA) for engineered wood products such as LVL (laminated veneer lumber) and plywood. GLA treatments have the advantage of incorporating the preservatives directly in the glue used to bond the wood veneers and hence ensures that the treatment is incorporated in the wood product from the inside out, not from the outside in as with conventional treatment. Azotek is the latest addition to this product family and uses state of the art chemical technology to provide highly effective protection against decay fungi and insects to LVL and related products for use in H1.2 application in New Zealand. LVL is an important innovation for New Zealand building offering high strength and reliable engineering properties for critical load and large span applications and now with the security of Azotek protection against decay and insects.

5 Copper-based Preservatives CCA stands for copper, chrome arsenate and this remarkable wood preservative has been in use for over 50 years. It has stood the test of time and even today is still preferred where timber and wood products require the highest levels of protection and reliability in demanding situations. CCA wood preservative is still the longest serving and most widely used timber treatment in New Zealand, Australia and many other parts of the world. Even in cases where CCA preservative has been withdrawn from some residential applications, it is often retained for utility, structural and rural uses where the maximum durability and engineering safety is essential. Uses: The unique properties of Tanalith CCA preservative make it the ideal choice where treated wood products must serve in demanding structural, ground contact or water contact applications. H3.2 as per NZ3640 for protection of structural wood products above ground such as decking, bearers and joists, and similar for H3 as per AS H4 for non-structural or non-critical wood products in ground contact such as fence posts, garden edges, landscaping sleepers et cetera. H5 critical or structural timber components in ground or fresh water contact such as house piles, utility poles and engineered earth retaining structures. H6 marine or brackish water contact such as wharf piles and similar structures in permanent salt water contact. Note that H6 specification for New Zealand application is not transferable to Australia or other countries. Timber Species: Tanalith CCA preservative is suitable for treatment of common softwood and hardwood timber products. Moisture content: Immediately after treatment, CCA treated timber will have a high moisture content. For H3.2 uses, it should be specified if the timber is to be supplied wet after treatment or re-dried (moisture content < 21%). Fasteners: CCA preservative treatments may be slightly to mildly corrosive to steel and other metals in contact with the treated timber. Galvanized steel or other corrosion resistant fasteners are recommended for all weather exposed or ground contact situations. Stainless steel fasteners and connectors (or other metals of high corrosion resistance) should be used for critical applications where very long service life is required or where additional sources of corrosion are present, such as salt. The treated wood should not be installed in direct contact with zinc-alum sheet roofing as corrosion may result. Use of prepainted sheet metal roofing is recommended and installation of a durable water resistant membrane between the materials. Disposal: Tanalith CCA treated timber offcuts and redundant pieces are not a hazardous waste. However it is recommended that care is taken to dispose of this waste properly (as a solid waste). It should not be mixed with green waste for composting and MUST NOT be used as home heating or cooking fuel as toxic fumes or residues may be produced. Use restrictions: The Environmental Risk Management Authority of New Zealand (ERMANZ now EPANZ) conducted a review of CCA preservative in 2003 with extensive reference to overseas practice and regulations as well as experience of use in New Zealand. They determined that there was no specific information indicating that CCA treated wood posed unacceptable risks for users and the community in New Zealand where used as recommended and that no restrictions on its use was justified at the time. However some overseas countries may have restrictions on the import or use of CCA treated wood products. Contact Lonza for further details.

6 Copper-based Preservatives cont... Tanalith E Tanalith Q Tanalith Eµ Lonza offer a range of copper based preservatives for protection of wood and timber products in general outdoor and ground contact use. These are environmentally advanced timber preservatives that incorporate copper in combination with azole or quaternary ammonium compound co-biocide wood protection system. The Tanalith copper based preservatives conform to the latest Unites States EPA, European Union and Australian directives regarding suitable wood preservative products for residential and close human contact use. Copper based preservatives are in wide use around the world including many countries in Europe, the United States and more specifically Japan, New Zealand, Australia in the Asia Pacific region. Uses: Tanalith copper based preservatives are ideal for common above ground (H3 / H3.2) and ground contact (H4, H5) applications that require robust levels of protection but where there may be sensitivity to arsenic or chromium containing preservatives. Examples are outdoor and garden furniture, decking, playground equipment, hand rails and landscaping in schools, public facilities or other areas where high levels of direct human contact are expected. Timber Species: Tanalith E and Tanalith Q preservatives are suitable for treatment of most common softwood and hardwood timbers. Being a dispersion (or suspension) product, Tanalith Eµ preservative is recommended for Radiata pine and similar softwoods only. Moisture content: Immediately after treatment, the treated timber will have high moisture content. For H3.2 uses, it should be specified if the timber is to be supplied wet after treatment or re-dried (moisture content < 21%). Fasteners: Tanalith copper based preservative treatments may be slightly to mildly corrosive to steel and other metals in contact with the treated timber. Galvanized steel or other corrosion resistant fasteners are recommended for all weather exposed or ground contact situations. Stainless steel fasteners and connectors (or other metals of high corrosion resistance) should be used for critical applications where very long service life is required or where additional sources of corrosion are present, such as salt. The treated wood should not be installed in direct contact with zinc-alum sheet roofing as corrosion may result. Use of pre-painted roofing is recommended and install a durable water resistant membrane between the materials. Painting: All Tanalith treated timber (CCA and copper based) can be painted like normal timber once dry and clean. Painting or staining of dimensioned timber in exterior, weather exposed situations is strongly recommended to minimize surface mould, checking, sun bleaching and dimensional movement. Product Tanalith E preservative Tanalith Eµ preservative Tanalith Q preservative Formulation Copper as a solution with azole co-biocide Copper as a micronised dispersion with azole co-biocide Copper as a solution with quaternary ammonium co-biocide

7 Azole-based Preservatives Vacsol Azure VACSOL AZURE is a new generation LOSP (Light Organic Solvent Preservative) treatment incorporating all carbon based and biodegradable triazole and synthetic pyrethroid active constituents. Vacsol Azure wood preservative provides effective protection against fungal decay and insect attack for above ground building applications. The key benefit of LOSP treatment is that it causes no change in the moisture content or dimensions of the wood products. Vacsol Azure preservative is ideal for protection of high value appearance and engineered wood products treated in final shape and form. Typical examples are exterior joinery and mouldings, finger jointed and laminated timber products and engineered wood products. Uses: H3.1 as per NZS3640 protection of non-structural wood products exposed to the weather and which are fully painted. Note that H3.1 LOSP treatment cannot be substituted for H1.2 treatment in timber framing for New Zealand. Painting: For New Zealand, most H3.1 treated timber products are supplied with a factory applied primer coating. All H3.1 treated timber products should be fully painted where exposed to weather. Timber treated with Vacsol Azure preservative is ideal for painting or staining providing that a few precautions are taken. Most importantly the timber must be conditioned for at least 7 days after treatment before painting to ensure that any excess solvent has flashed off. In industrial production facilities applying preprimer this time may be accelerated by forced air drying, vacuum drying or other means. Fasteners: Vacsol Azure treatment is not corrosive to steel or other common metals so no deviation from normal practice is called for. However corrosion resistant fasteners are recommended for all exterior or weather exposed timber work. Australia - H3 as per AS for protection of general structural and non-structural wood products above ground. Timber Species: Radiata pine Plywood & LVL: Due to the nature of plywood and LVL it is recommended that additional conditioning time is allowed for depending upon drying conditions, the types and thickness of plywood or LVL treated and the amount of preservative absorbed during treatment. The Vacsol Azure Treatment Process Dry timber is placed into the treatment chamber and depending on the process used, a partial vacuum or even low pneumatic pressure is applied The solution is quickly drained away and a deep final vacuum removes up to 90% of the fluid in the wood leaving a relatively small residual The cylinder is rapidly filled with LOSP preservative solution without changing the initial pressure so that all the timber is in contact with LOSP fluid. The fluid is pressured briefly to drive it into the timber

8 Azole-based Preservatives cont... Vacsol Aqua PT Vacsol Aqua PT is a waterborne, multifunctional wood preservative system for timber used above ground containing fungicides (propiconazole & tebuconazole), insecticides/ termiticides (permethrin and/or imidacloprid) with optional anti-mould additives and water repellent agents. Uses: Under AS Vacsol Aqua PT treated timber can be used for general outdoor, exposed, above ground situations including decking, bearers and joists, fascia, weatherboards, plywood cladding, door and window surrounds, hand rails, laminated posts and beams, etc. In New Zealand, outdoor uses include H3.1 which are fully painted and for non-structural application such as cladding, fascia and reveals. Section B2 Durability of the NZ Building Code allows water borne azole treatment for H1.2 (framing). Treatment of timber products destined for the US market can be deemed equivalent to AW- PA UC3A requirements (close to NZ H3.1) and possibly UC3B in some cases. Consult Lonza for further details. Timber to be treated should be kiln dried to less than 20% moisture content (<16% preferable), be in final shape and form with all machining completed before treatment and be free from decay, mould, insect attack and sapstain. Lonza will advise on the most appropriate treatment schedule for the commodities being treated and specifications to be met. After treatment, timber should be allowed to air-dry in a well-ventilated area for at least 48 hours before wrapping or further processing. Painting, Gluing & Fixings: Timber treated with Vacsol Aqua PT preservative can be painted with alkyd or acrylic based paints once dry. All normal wood glues are compatible subject to checking moisture content. The treated timber is not corrosive to steel, aluminium or copper alloy fixings. However corrosion resistant fixings (galvanized steel as a minimum) is recommended for all timber in exterior applications. Timber Species: The Vacsol Aqua PT treatment is intended for kiln dried timber such as Radiata pine in a conventional vacuumpressure plant. Consult with Lonza regarding the treatment of other timber species.

9 Additional Application Notes Identification and branding: Tanalised protection cannot be applied by the end user or on site. A conforming Tanalised treatment can only be provided by pre-treatment in dedicated industrial facilities. All treated wood and timber products should carry a treatment brand that identifies the treatment or hazard level to which the product has been treated, the preservative used and the identity of the treatment provider as follows; Suitable Applications: The range of Lonza wood protection products covers applications in all the hazard levels listed in NZS3640:2003. It is important to understand that treated timber and wood products must not be used in a situation at a higher hazard level than that for which it was branded. For example, timber branded for H3.2 application should not be used in ground contact (H4), and timber branded H4 is not to be used in an H5 application. Note that New Zealand treatment specifications do not necessarily align 100% with standards or requirements in other jurisdictions. It is strongly recommended that specialist advice is sought prior to specifying treatment for export markets. Safety & Environmental Protection Moisture content: Structurally graded timber (Radiata pine) should be supplied with moisture content less than 21%. Most general outdoor and ground contact treated wood products will be supplied wet (moisture content > 21%). Contact your wood supplier for details. Reworking after treatment: Treated wood and timber products should not be re-sawn or re-sized after treatment by end users (except for cutting to length or notching as required for fitting and joining). These processes may reduce the protection afforded by the treatment. Where timber is cut or rebated in H3, H4 and H5 situations, the exposed area should be resealed with a suitable in-can protective such as Tanalised Enseal to ensure that an integral protection envelope is maintained. In H4 situations it is recommended not to place a cut end in ground contact. For H5 applications a cut end must not be placed in ground or water contact. No cutting or notching should be done after treatment on H6 level treated timber in the water contact zone. Painting: Painting improves the appearance and dimensional stability of treated wood and timber products. It is strongly recommended that all finished and sawn timber in weather exposed applications is painted, stained or sealed to reduce surface deterioration, checking or dimensional movement. Treated timber can be painted or stained like normal untreated timber providing that it is dry and clean. Always follow the paint manufacturer s instructions. Nails, bolts, fixings and metal in contact with wood: Corrosion resistant fasteners, fixings and connectors should be used for all timbers in weather exposed, damp or ground contact applications. See details under each preservative summary. Wood preservatives are generally restricted use products and require appropriately trained operators to use and handle the chemicals (Approved Handlers). Wood preservatives are required to be registered with the New Zealand Environmental Protection Authority. Safety Data Sheets (SDS) and other safe handling information resources are available from Lonza. Wood preservative processing is a notifiable activity requiring appropriate trade or site use consents. Industrial timber treatment plant facilities are required to conform to strict environmental regulations and are under the jurisdiction of environmental protection and / or regional authorities. Treated wood and timber products are safe to use however as with handling many materials, certain precautions should be observed, particularly where machining or sanding generates wood dust and air borne residues. Keep work areas clean, avoid accumulation or inhalation of wood dust and wash hands after handling the materials. Treated wood wastes and off cuts are generally not considered to be a hazardous waste. However, care should be taken to dispose of this waste appropriately through normal disposal services. Treated timber wastes should not be mixed with general green waste for composting. Treated timber should not be burnt in uncontrolled situations such as for cooking or home heating. Further Information For further sources of information contact the NZ Timber Preservation Council. This information is presented in good faith and is believed to be accurate, based on the best available advice and knowledge at the time of printing. However due to the variability of application situations, the user must satisfy themselves as to the suitability of the information or the products for any particular purpose or circumstance or take suitable expert professional advice.

10 RELEVANT STANDARDS The following are examples of national and joint standards which are directly relevant to preservative treated wood products. Other standards may apply or be called on by these standards. NZS 3640 AS/NZS NZS 3602 Chemical Preservation of Round and Sawn Timber covers treatment requirements for treatment of round and sawn timber. AS/NZS 1604 parts 2 to 5 cover requirements for treatment of composite, laminated and veneer based wood products. Timber and Wood-based Products for Use in Building NZS 3604 New Zealand Building Code Timber Framed Buildings Also see Clauses B2 Durability and E2 External Moisture of the New Zealand Building Code for latest acceptable solutions which may not be reflected in current standards. HAZARD LEVELS & APPLICATIONS Summary of Lonza Wood Preservatives for Key Applications as per NZS3640 Treatment (Hazard) Levels Hazard Level Exposure and Service Hazards Specific Application Examples H1.2 Interior, protected from the weather, but with the possibility of exposure Framing and interior construction timber not in direct weather exposure (see NZS 3602). to moisture. Minimum Retention Levels 0.08% m/m azoles (3) (see NZS3640 for full details) 0.40% m/m BAE (2) Conforming preservative (and number (1) ) Framebor N (11) Diffusol (11) Vacsol Aqua PT (64) LVL for H1.2 Triadimefon + cypriconazole (7) Azotek (66) H3.1 Outdoors, exposed to the weather, above ground Exterior non-structural building components, cladding fascia, joinery see NZS % m/m azoles (3) Vacsol Azure (64) Vacsol Aqua PT (64) H3.2 Outdoors, exposed to the weather, above ground, or with a risk of moisture entrapment All H3.1 uses, plus outdoor structural applications and decking see NZS % m/m copper + azole (4) 0.35% m/m copper + DDAC (5) 0.37% CCA elements (6) Tanalith E (58) or Tanalith Eµ (88) Tanalith Q (90) Tanalith CCA (01) H4 Exposed to the weather, in ground contact Non-structural or noncritical timber in ground contact - fence posts, landscaping timbers 0.42% m/m copper + azole (4) 1.02% m/m copper + DDAC (5) 0.72% m/m CCA elements (6) Tanalith E (58) or Tanalith Eµ (88) Tanalith Q (90) Tanalith CCA (01) H5 Exposed to the weather, in ground or fresh water contact House piles and poles. Crib walling or other engineered earth retaining structures 0.76% m/m copper + azole (4) 1.35% m/m copper + DDAC (5) 0.95% m/m CCA elements (6) Tanalith E (58) or Tanalith Eµ (88) Tanalith Q (90) Tanalith CCA (01) H6 Marine or brackish water exposure. Marine borer hazard Marine piles, jetty cross -bracing, landing steps, sea walls 0.40% m/m copper (as Cu only) Tanalith CCA (01) (1) Every recognised preservative type has a number assigned for identification. See NZS3640 sections 4 and 5 for details of preservative specifications and identification numbers. (2) BAE stands for Boric Acid Equivalent (H 3 BO 3 ). (3) Azoles as combined retention of propiconazole + tebuconazole. This treatment also includes an insecticide where there is a termite or wood borer hazard. (4) Azole as tebuconazole alone or as tebuconazole + propiconazole (1:1 ratio) (5) DDAC is didecyl-dimethyl ammonium chloride or carbonate (6) The term CCA elements means the total of copper (Cu) plus chromium (Cr) plus arsenic (As) elements. (7) As glue line additive + face veneer application see NZS3640.

11 Arch Wood Protection (NZ) Ltd A Lonza company 265 James Fletcher Drive Otahuhu Auckland New Zealand Tel: Fax: tanalised.nz@lonza.com The information contained herein is believed to be correct and corresponds to the latest state of scientific and technical knowledge. However no warranty is made, either expressed or implied, regarding its accuracy or the results to be obtained from the use of such information. Some products may not be available in all markets or for every type of application. Any user must make their own determination and satisfy themselves that the products supplied by Lonza and the information and recommendations given by Lonza are (i) suitable for intended process and purpose, (ii) in compliance with environmental, health and safety regulations, and (iii) will not infringe any third party s intellectual property rights. Lonza 2015 All copyrighted material has been reproduced with permission from their respective owners, all other materials 2016 Lonza. Tanalith, Framebor, Vacsol, Diffusol, Azure Aqua, Azotek, Enseal and Tanalised are trademarks of Lonza Group or its affiliates. October 2016