We take it the KD hardwood you refer to is Vic ash. Light-red meranti is rated Durability Class 4, and Vic ash Durability Class 3 according to Australian Standard 5604, Timber - Natural durability ratings. Durability Class 4 implies a probable service life of up to 7 years while Class 3 implies a probable service life of up to 15 years outdoors above ground. The ratings apply to raw timber without a coating or preservative treatment. With a well maintained paint coating they would be expected to achieve the predicted life and possibly longer, depending on weather exposure, eaves overhangs, etc. However, for a long life we recommend preservative treatment in both cases. You will find companies that produce meranti windows treated with Light Organic Solvent Preservative (LOSP) by searching the net. Preservative treated Vic ash is available under the trade name Iron Ash.Window joinery
Answered on 04-05-2021
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