We've been working hard these past two weeks on replacing the flooring on the main floor of our home. We had to move all the furniture and find new temporary homes for it. Then we had to pull up the carpet, padding, tack strips, and staples. 
I found some interesting stuff under the carpet. I should have taken a photo of the stuff for the record. 
Imagine here a photo of the following stuff all lined up next to a ruler for scale (archaeology skills my friend) a nickel, the starting end of a tape measurer, two rusty razor blades, the pull off tab part of a disposable coffee cup lid, two plastic beads, speaker wire, and a pile of dirt. We knew that the carpet was 6-3 years old when we bought our house (since the previous owners had put it in), which would make it 11-8 years old now. I found evidence of previous carpeting (brassy staples with remnants of green padding). The 'archaeology' got more interesting in the kitchen/entry area. 
The subfloor is higher in that area which led me to conclude that it was originally tiled with vinyl glue down tile (that and finding said tile which is also underneath the cabinets). The carpeted area was lower so it would be level with the padding included. Over the original vinyl tiles, someone installed a sheet vinyl floor. The bucket of vinyl floor adhesive used for the job was recently taken to the dump by us. Our utility room is like a previous fixture/floor or window covering/parts cemetery. Nobody before us seemed to want to throw anything away (we're either the 3rd or 4th owners of this house). The people we bought the house from put in laminate flooring in the kitchen and entryway, right over the partially removed sheet vinyl floor. 
Maybe they tried to remove it all but gave up? Kind of like the sheet vinyl installer tried to remove the original vinyl tiles but then gave up. Needless to say, the floor wasn't nearly as level as we thought it would be in that area. We had no illusions about the rest of the floor. We knew it was way off level (as is just about everything in this house). We tried to make things level (or at least flat) using roofing felt (I got that idea from the internet). It was an interesting process. I'm not sure how well it actually worked. Hopefully the new floor doesn't break or fall apart or something. 
In the kitchen and entry way we pulled up the rest of the sheet vinyl. 
Bob chiseled off the vinyl tiles that were in the front closet so it would be level with the rest of the entry way. Here's the transition between the entry/kitchen and the rest of the floor- seemless, right? Hopefully it keeps looking that way. 
