To fix that I would have had to either rip up the whole bottom floor of my house, go underneath and jack them up, or double up the floor joists.

There is no question that it was affected by the nationwide downturn three years after opening but what a great project:Atlantic Station is located on the site of the Atlantic Steel mill, which opened in 1901.[1] The steel mill was nearly closed in the mid-1970s, but it remained nominally operational primarily to avoid the huge costs it would have required to remediate the soil contamination present after years of operation.[2]Developer Jim Jacoby, who also redeveloped Florida's Marineland, began putting the project together in 1997 when his company became the property contractor of the land.

If what is underneath is compact enough (looks like a gravel base) I'd slap another layer of asphalt right over the top, thickening up what is there now and filling in the bare spot up to the level of the rest.

If it is particle board I would replace it.Here is a technique for getting rid of the oder for good,Remove carpeting, padding and other flooring around the areas you suspect urine has leaked into the subfloor.Apply an enzymatic pet cleaner (like Nature's Miracle) to the soiled areas and allow them to dry thoroughly for 24 to 48 hours.

I had the stump ground out and some new soil/seed put in.Hope this helps.

Yeah I have a friend in army with 706 credit so I don't have to rely on parents credit and from looking at the house its just cosmetic needs like paint carpet and maybe a little modern updates but everyone once you start taking things apart there maybe some other damaged underneath but from the look I think 10,000 in repairs would do the job.

Get a vibe of what is going on underneath the numbers or that hidden future value.

Because they do not interlock, you can see the subfloor underneath.  

Otherwise it is in the soil below the slab.

If done after the rehab, it provides an opportunity to address residual issues prior to putting the property on the market, although the downside is that it could mean tearing out newly installed flooring, cabinets, and appliances to address serious problems like mould underneath the subfloor that we’re not initially identified.Any thoughts?