Posted 01 Sep 11 09:42 AM
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
Posted 03 Sep 11 01:16 AM
"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".
Posted 03 Sep 11 08:34 AM
do you think there is anything we can do.... I mean so many builders and other people who work with that kind of timber.....
Posted 03 Sep 11 09:27 AM
Posted 02 Oct 11 09:49 PM
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.
Posted 26 Apr 14 10:14 PM