Can I paint a flakeboard floor?

You can seal it with a polyurethane- that will enhance it's look and keep it durable.

This floor has been covered with a technique using simple brown paper. Google for more info.

I feel your pain. I was so disgusted by the carpet that was old when we moved into the house ten years and two dogs before, I finally had enough, and started ripping it out and carrying it to the dumpster. My husband, when he saw the dirt of about 20 year's west Texas winters UNDER the underlayment, got with the spirit, and we ripped it all out in an hour. We discovered loose and broken linoleum tiles underneath dating back to the 50's when the house was built. We we down to bare concrete by the end of the day, and even though we had to live with it that way for several weeks until we could lay tile, I felt so much better about it! Your subfloor is particle board. If it is not stiff, you might want to put a thicker plywood on top of it for strenght. (if it feels bouncy, squeeks, or gives when you walk on it, it needs another layer. Even a second layer of particle board is better than nothing, but an outdoor grade plywood would be better. ) A water based epoxy floor paint (think garage or porch paint) will fill and smooth the surface a bit, and be sweep/mop/vacuum friendly for cleaning. Frankly, even if it doesn't last more than a couple of years, I know how good it feels to get an old dirty carpet out of the house. It will be worth it. Had we not been able to tile, I would have painted it to prepare for guests.

If the pet urine is on the floor, suggest to seal floor with Kliz oil based paint. The seal will lock in any smell that penetrated the wood. It works! The white color will give the floor a clean canvas. Select a color(s) and techniques to make your floor look good. After removing my carpet, patched the holes with Gardner Flex and Fill patching paste. It dries hard. Then sealed with Kliz, I used epoxy garage paint on my living room floor.

Here are the steps:

1. Remove carpet and vacuum up any dust.

2. Patch any holes and level with a light sanding. Vacuum up dust.

3. Paint to seal with Kliz oil based paint.

4. Paint the base boards (if needed)

5. Paint with a epoxy garage based paint (select roller for smooth/semi-smooth finish.

Home Depot has all of these products. Best of Luck!

If your subfloor is particle board, I'm surprised it's held up this long and no one has fallen through . Please reinforce with plywood or hardy back before painting or laying any other kind of floor cover .