| tart --> | | | | municipal projects. |
| Whilst hardwood is generally the preferred lumber | | | | Although there is apparently no firm scientific proof |
| species for exterior decking due to its hardness, | | | | to support the contention that CCA timber is harmful |
| resistance to wear and attractive colour, softwood | | | | to health provided it is handled correctly, such |
| species are commonly used, particularly where cost is | | | | cautions or bans have been instituted as a |
| an important factor. But the drawback of most | | | | precautionary measure. Nevertheless it is always best |
| softwoods is that they are not naturally durable so | | | | to err on the side of safety, so it is recommended |
| are unsuitable for use in areas fully exposed to the | | | | that when working with CCA treated lumber, to |
| weather unless the wood is properly treated with a | | | | apply protective clothing including goggles, face mask |
| recognized wood preservative or completely sealed | | | | and gloves. CCA treated lumber also should never be |
| with an impervious surface coating. So when selecting | | | | burnt in an open fire but must be disposed of |
| a softwood species, one of the most important | | | | according to local regulations. |
| considerations is that these species used should be | | | | Fortunately a number of alternative wood treatment |
| either a recognised naturally durable species such as | | | | products to replace CCA are now available, the most |
| Western Red Cedar, some species of cypress, larch | | | | common of which is probably ACQ (alkaline, copper, |
| or pine, or that it has been treated with an | | | | quaternary). Such products use low toxicity, active |
| appropriate and good quality preservative. | | | | ingredients such as recycled copper and modern |
| For more than 70 years, the most commonly | | | | organic biocides to give the lumber the required |
| accepted wood preservative treatment chemical has | | | | long-term protection against wood destroying fungi, |
| been CCA (copper chrome arsenic), which gained | | | | termites and other wood eating insects. Although |
| popularity due to its effectiveness and relatively low | | | | such products have not been available for a |
| cost. (CCA treated lumber can normally be | | | | sufficiently long time for extensive natural durability |
| distinguished by the greenish tone it imparts to the | | | | data to be collected, most manufacturers will provide |
| wood). However in recent years, many national | | | | at least 25 years guarantee on the life of treated |
| organisations and authorities have announced either | | | | lumber. |
| bans or restrictions on the use of lumber treated | | | | So if you wish to use a softwood species for your |
| with CCA. For example, in Australia from March 2006, | | | | deck, check what preservative treatments have |
| CCA treated timber will no longer be permitted for | | | | been applied, and especially with the newer |
| use as handrails, decking boards, picnic tables, or | | | | preservative treatment chemicals, ask what |
| children's playground equipment in new installations. | | | | guarantee the lumber supplier is prepared to offer on |
| And in Japan, CCA treated lumber is generally not | | | | the lifetime of the decking material. |
| permitted any longer for public use in major cities for | | | | |