"Luxury" Vinyl

[Spicoli43]

That looks to me like someone put a 1/8 chip board over the top of the sub floor, maybe even over another layer of vinyl. Which was pretty common in my area in the late 70's and 80's. If it was me I would replace the floor down to the studs. IF your house is 70's or 80's then suit and mask up, seal off, and filter and exhaust the air as you work... If you can't guess why I am saying that then you should not proceed.

Thanks, but I have lived in 70's houses as a kid. I won't do that again. It's 2006, MDF.

 

[Spicoli43]

Well, I took the sub floor out, and there is no way to replace it. I put in a piece of plywood along with a scrap of the vinyl, and compared the height to what the vinyl would be in the hallway. With the transition strip, it's just not possible. It would create an instant trip hazard.

I'm at the start of the other bathroom now in the pic, and I know the industry standard to use sub floors in bathrooms pre dates widespread use of wood / vinyl plank, but I'm struggling to figure out why they would use it? Taking it out isn't breaking my heart, it just takes a long time.