Solid Hardwood, Engineered and Laminate Flooring - Old Home Flooring Sags

I am a sucker for an old home...they just have a lot of character. Unfortunately, with all of that character you have problems to fix. The latest issue I want to tackle are the floors in my kitchen.

First some background information about the house. It's a 100+ yearold farm house that has a stone foundation with no visible crawl space. The main watermain from the outside was hooked up via someone cutting a hole in a closet floor and crawling underneath the home (approx 2.5 ft tall). So back to my issue...

The floors in the kitchen (wood floors) sag. There was an old wood stove in there that hurt the floors (created the sag) and there is NO subfloor (they didn't believe in them back then :( ) which led to moisure coming into the wood via humidity etc. The area of the kitchen flooring that sags is approx. 10 square feet out of about 230 square feet. What I'd like to do is put some type of subfloor on top. I understand it will raise the floor approx. 1" but that does not worry me.

What do you guys recommend the best way to tacke this? So the two issues:

1. Sagging wood floors need to be replaced (via new subfloor then new hardwoods).
2. How can I lay a new subfloor over the existing sagging (in parts) flooring?

All advice is much appreciated - this is racking my brain as of late.

-Paul :wall:

If someone crawled underneath to get to a pipe, someone needs to crawl underneath and jack and brace to level the house again, before it gets worse.

Adding more weight to the top right now might not be the best thing until you stabilizr the foundation and floor structure.