LOL, what about a short handled scraper? Its not too big of an area, will it be worth it buying a scraper for this small job?

Short handled scraper is good if you want to kill your back. A long handled one should only cost $10-15.

Just had DH sharpen a farm tool that we have, he calls it a scraper. Its from a farm store. I'm using it. Long handle and all :)

Go to home depot to purchase (or rent from a tool rental company) a 4" scraper, which can come roughly 18" long or 4' long. You have choices with the length of the scraper.

I've removed it from oak hardwood and from concrete floors.

Judicious scraping and then solvents on the oak.

Floor scraper, professional quality with replaceable blades, worked great on concrete. Long handle and relatively heavy. The weight of the scraper was an asset because the weight worked for you.

OSB? Have my doubts on how well a scraper will work.

I suggest you make a decision on what you'll be replacing the carpet with before investing too much energy in the project. Might be easier to just pull the OSB up and replace with whatever underlayment is specified for the new floor covering.

I'm having success with what I'm using. I don't live near a store without driving 30min or more. So this 6" wide, heavy duty tool with a long handle is working fairly well.

Do the ones at the big box stores get the glue off too without any elbow grease. I am having to use force to get the rubber to peal off, but its coming off. There is still a powdery residue that is stuck to the floor. I might wet that down later and try scraping that too.

If I were to put hardwood flooring down, would I need to get all the glue off, or is a faint amount ok? Its not bumpy nor is it ridgy though you can see where the trowel applied the glue.

Ha, the floor isn't really OSB, now that I see it. It looks like small to tiny particles and appears to be 5/8" thick. And as I mentioned about, the flooring people who put the hardwood in 4 years ago told me it was over a layer of ply that is the same thickness.

The carpet is gone! I would paint it and lay a polypropylene outdoor rug down, rather than keep that carpet in the room.

Also, I have to correct my initial post, this isn't my last floor project :( I have a mudroom floor that is in my future.

Now I have to get up from this computer and bag up the rubber, that I've scrapped. Next, vacuum, then do some more scrapping of the bits left over.

Here is a closeup of the top 5/8” subfloor. Maybe it’s not actually called the subfloor since there is more subfloor under this.

This is the mess.

My inlaws used to have a dog in the house at any given time. I think they must have come back to this guest room to pee. Looks like a lot of round stains:

I was going to say yesterday if this is from the 70's that would not be OSB, more than likely it would have been particle board underlayment put over the subfloor, as OSB was not popular or maybe not even available then.

Particle board for sure. The only thing that likes going over top of particle board is carpet or floating flooring (do not nail into it...it will only work itself loose and drive you nuts).

If there are pet stains, you might as well pull up the fibre board and start again with a fresh subfloor layer of good-side-up plywood. It will make your decisions in the future SOOOOO much easier.

I could pull up the particle board, but there is ply under that. The other hardwood floor went on this combo and they used longer nails. Is that OK?

Lets say I pull up the particle board. What type ply do I get to go over the 5/8"ply that I believe is the subfloor? How often do I screw down the edges? Do I screw down the field as well? Do I need to worry about hitting the joists, since the existing plywood would be connected already.

Just got the job for hardwood flooring in the works and they can be here 3rd week in May. I would have the floor ready for them, with either a clean existing floor, or a new "good-side-up plywood". I am now leaning towards taking up this dirty crap.

HOW DO YOU GET THE PARTICLE BOARD UP? I believe it is nailed, because I have run into a few heads with the scrapper and think they might be nails. But I haven't looked yet.

The floor is scraping up cleaner than I woulda' thought. But, yeh, that's particle board and I would remove it rather than continue to scrape.

It should pop right up if you can get a pry bar under it. Wedge a thin pry bar between the seams, near a corner. Will probably pop up and the good section of the corner will break off and give you a larger area to get a purchase on. Before removing, you might want to set a skilsaw to cut a hair over 1/2" deep and 'score' the particle board into more manageable sections. That stuff weighs a ton.

We have removed some of it from this house. I think there must have been an underlayment grade because what we pulled up wasn't even a good grade of particle board. The plywood underneath in this house is only 1/2'' stuff. We put screws thru the 1/2 plywood into the joists because it was nailed only and not even with flooring nails.

Then notch troweled on subfloor adhesive and covered with 3/4" plywood. Screws into the plywood, not the joists. Made a huge difference. Really stiffened up the floor and not even a hint of a squeak.

ci-lantro thanks very much for the tips on scoring and the instructions on the install, especially the tip on refastening the subfloor with screws.. I bet there are nails in my plywood too, since the particle is down with nails. But I have to say these floors are stiff now. I'd love to talk to the gentleman who did this addition in the 70's but he passed away 2 years ago. He was in is 90's. I have never had any complaints with this addition.

It looks like the particle board is fastened about every 8-10" through out the field and at the edges at this time. Is that how you did it? I've put down exterior grade ply in my bathrooms to ready the floors for prime, electric heating, and self leveling compound before ditra and tile. I know not to line up the seams. I put down screws every 4" on center for those floors.

DH doesn't want to take the particle board out. He's busy with farming and says he doesn't need another job, lol. I do a lot of the work, but with the heavy lifting, I need help. I could remove it myself and then its done. But I don't know if I can get help to put the plywood in place.

ETA, If I replace with plywood, it will need to be the same thickness of the particle board so I have a nice transition to the hardwood in the hallway.

Can I cut all my 4x8 plywood into 4x4, and still have a good install? I could carry the 4x4 I think.

ETA, can I do the overpayment without using glue?

Thanks @ci-lantro! I like the idea of ripping 2x8. I believe the joists are 14’ which isn’t too long. I don’t understand why plywood needs to be oriented at 90* because it already is oriented multiple times within the structure of each unit.

Structurally more sound. Improves stability but then plywood is pretty stable anyway. Maybe because there are more of the plys are orientated lengthwise? Or maybe to do with having the joints perpendicular to the subfloor joints--the joints being the weak link? Not sure. Could be a holdover from when the subfloor and finish floor were strips of real lumber?

Since plywood already accomplishes this to a degree as you pointed out, it probably doesn't matter a whole, whole heckuva' lot if you don't install it perpendicular but, IMO, best practice would be to do so. (I did go thru my scrap pile and use up a lot of smaller pieces of ply around the perimeter of the room which I am sure isn't best practice. I just hate cutting up a whole beautiful sheet of plywood for less than half sheet fillers!)