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Posted 01 Sep '11 09:42 AM

Hi out there I have done a bit of reading on timber-treatments after I have worked with LVL beams. They where sort of oily and the smell unbearable. Back home I had headaches which I kept for 2 days. As much as I appreciate our mutual effort towards healthier buildings, where is the point in healthy buildings when the guys who build them "suffer" (maybe even long term) ill health by putting them up.

I wonder whether anybody here knows more about that, especially if there is "something" out there who tries to oppose that kind of treatment. (Or treatment in general)

Thank you Ingo

Re: Treatments

Posted 03 Sep '11 01:16 AM

Hello 'zimmerer', I posted this in November 1010 and think it relevent to your comment above.

"We used to use heart Rimu, Totara and Matai for frames that resisted rot and insects - until we turned those timbers into a rare resource, and so now we have to use alternate soft wood Pinus Radiata that requires ‘treatment’ to extend its life. CCA treatment (‘C’ for copper) resists fungus, protection from borer or termites (‘A’ for arsenic) with chromium the remaining ‘C’ to ‘fix in’ the other two poisons and avoid leaching. All nasty carcinogenic stuff.

Then there is LOSP treatment which is less hazardous to the environment but with volatiles given off until ‘flash off’ is completed, a real health risk for the builder – I wouldn’t touch it.

However, there are substitutions available. We could, and in my opinion should, revert back to the Boron derivatives for all low risk H1 to H3 situation treatment such as non critical framing, windows and protected decks Etc, but note that this does not protect against fungus rotting. Then we could use CCA only when essential, such as for H4 and H5 substructure, deck supports and landscaping requirements.

All those who criticise, should show us the economical, sustainable alternatives – historically, Oak for structural framing? Ebony or heart Jarrah for wharf piles? Not an easy choice. I don’t consider Oak or Jarrah a sustainable resource.

Some timbers such as Lawson Cypress, Western Cedar and Douglas fir can be used untreated if alternating from wet to dry – life expectancy 15 – 20 years in a H3 situation".


Re: Treatments

Posted 03 Sep '11 08:34 AM

thank you don't get me wrong. under certain circumstances treatment is fine. Framing and roofing timber shouldn't be treated at all. (but you are right:as long as it is dry). I just wonder who has made the call on these treatments. (obviously not the people who process it).

do you think there is anything we can do.... I mean so many builders and other people who work with that kind of timber.....


Re: Treatments

Posted 03 Sep '11 09:27 AM

Radiata has lost a lot of appeal for me with all the chemical treatment.. I am sure you would agree that good design and workmanship would make treatment in most cases not needed. IMO I can't see anything sustainable in a house built with toxic treated timber. Before building with treated pine I would rather use concrete. We are lucky that alternatives are available such as larch, douglas fir, lawsons, macrocarpa, baltic pine, redwood or cedar.

Re: Treatments

Posted 02 Oct '11 09:49 PM

Hi Ingo, Recent changes to timber treatments requirements mean that more boron treated timber can be used. I'm not sure whether LVL timber can use boron treatment, I know that they can't use CCA, from memory due to incompatibility with the glues.

I doubt the people who make the decisions on which treatments are suitable ever have to deal with the product, so don't suffer the consequences of dealing with the timber, however they will have to deal with the consequences of any legal action so my guess is that they prefer to err on the side of a bit more builder discomfort.

It would be interesting to see what OSH's perspective is on the issue.

Re: Treatments

Posted 26 Apr '14 10:14 PM

Hi there -totally agree with your sentiments. At Abodo Wood we have been developing low (or no) toxicity wood products for the last 10 years. All species are grown right here in New Zealand. We use technologies like thermal modification, and water based azoles to provide durability less the toxicity. We also developed a good old fashion doug fir heartwood cladding - which works a treat. As our products are generally 'alternative solutions' we went to the trouble of getting Codemark certification- which keeps the council happy. Check out our range

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