Protecting Bottom Wall Plates in Brick Veneer Extension

Hi,

I am an owner-builder adding a brick veneer extension to my exiting brick veneer home in Adelaide, SA. I am about to build the wall frames myself. I see the wall frames in other new brick veneer houses being constructed nearby are built entirely with untreated timber (MGP10 pine), as I believe is the case in my existing home. My approved plans have not specified any treated timber for the wall frames.

My question concerns the bottom plate of the new wall framing I am going to build. Is it worth making these treated timber, to protect against moisture coming through the concrete raft footing and/or in case the floor somehow (rarely) gets wet and water reaches the bottom of the frame ? Or is using treated timber here not important and perhaps only inviting problems with the nails or other fasteners deteriorating due to the chemicals in the treated timber ?

Additionally, is it worth placing a plastic damp-course under the bottom plates ? This would seem to me to be a good idea, but I don't seem to see it done anywhere... ?

Thank you for any thoughts or advice you might like to offer.

Mai-au.

I always use malthoid in this situation 110 wide.

mai-au
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