This was the balcony of a terrace obviously built by an owner developer..[this terrace 1 of 6 in the development] who had no idea of good building practice and built things the quick an easy way without any knowledge of timber properties or any interest of traditional styles. The 3rd photo shows reinstalled balustrade and metal posts…completely out of character.
What had occurred here is the main support beam was of timber species oregon [unsuitable for exposed external application] overlaid with fibrous cement sheeting under the tongue groove flooring on top. Of course the fibrous cement sheeting stopped the deck from leaking but it provided a swimming pool for tongue and flooring to float in…which caused everthing to rot to point of the balconey being unsafe to venture on. The problem was further exacerbated by no maintenance of the front gutter which then dripped for days on the deck after any rain.
We replaced the main support beam and decking re installing the old balustrading and metal posts and had an associate roofer re do the front gutter. Should be good now for 40 + years as long as maintenance is kept up.
References: Timber supply: Rallis Timber