Crawl Space to Slab Conversion
I live in a 64 year old house at the NC beach with a 6" below grade sand crawlspace. This only leaves about 10" of open space between the sand and the bottom of the floor joists, with the finished floor being about 18" above grade.
Between the occasional hurricane overwash in the '90s and poor ventilation, the floor joists have all dry rotted - causing the old maple wood floor to sag 2" - 3" in the middle of the 20' span.
This is only an issue on the oldest, un-remodeled half of the house which comprises two bedrooms and the living room - so there are no plumbing or electrical lines running under the area.
5 years ago I tunneled under the house and tried to shore up the middle of the 20' span with 6"x6"s, but even then some of the dry rotted joists were starting to lose their integrity.
I imagine the "money is no object" solution would be to jack up the whole house and set her on pilings, but that's not economically feasible right now.
I hesitate to replace the joists with new ones, because I'll still have the below grade and moisture with lack of ventilation problem.
What about tearing out the old floor and joists (while supporting under the existing walls - which are non load bearing) and bringing in fill dirt to get me above grade and then pouring a 6" concrete slab?