Advice for subfloor and bearers

Hi this is my 1st post after many months of getting great ideas and solutions from you all so thanks!

I bought a 2 bedder semi in inner west Sydney last year and the timber floors are a problem - the bearers are rotten / weakened in most of them (no active termites at this stage) - some of the beams also run under the neighbors house as well which squeak.

Due to the bearers being weak they are springy and stuff now falls off the shelves! I have tried to get some trades men to fix it but the usual story is the job is too small for them to look at (there is also an access problem as there is only about .05 - 1 metre crawl space under the rooms). I have gotten under there and put some blocks under but these are sinking into the soft soil so i need to get this professionally fixed (probably need to pull all the floor up and start again)

Has anyone any suggestions on tradies who would do this in the inner west of Sydney etc...

Any help or advice would be greatly appreciated:)

Ar you sure it is the bearers or is it the stumps that support them? It's probably not as difficult to get a small stump job done if that was the case? Bearers will always be springy if the centre supports are missing.

Thanks OBBob for the reply

Maybe i have the terminology wrong - the beams which run under the floor boards seem to rest on the bricks which make the foundations of the house - there is nothing at all to support them in the middle of the room (but the rooms are small - about 3.5 m x 4) but as a consequence the hall and bedrooms are springy

Where the beams rest on the foundations there is some definate loseness - maybe there is some form of packing i can put in there other than the off cuts of wood which seem to be there now?

i can see that some of the beams (under the floor boards) are rotten and very soft and some of the nails which hold the floorboards in place dont hold tight anymore.

The crawl space is very limited in places (less then a metre)