I found the below online and tried it:
TLDR:
- boil water
- throw boiling water on floor and let sit 5 to 10 minutes
- scrape soaked parts with heavy duty scraper
- using a wire brush helped in some spots
How To Remove Yellow Carpet Glue or Adhesive
If you have ever tried to remove that yellow carpet glue from under a
wall-to-wall carpet or rug that you have removed from your floor, you
know exactly what I'm talking about. You know how difficult it is. I
have tried just about every chemical that is available at Lowe's.
You would think that someone there would know exactly what to do to remove
it, but nobody does....(I've asked) and if they do, they aren't
talking.
I have just gone through this dilemma and you won't believe
it, but I have found a fix. Actually, it was not I who found the fix,
it was my neighbor, who I would refer to as "extremely intelligent."
After trying many different chemicals and cleaners, including Goo-Gone
(I really thought it would work), and even after trying to use a heavy
duty sander (wrongly recommended to me by a carpet store) that I had
to rent from a machine rental place, I came to the conclusion that it
was going to be impossible to remove the carpet glue from my floor. But I was
wrong.
My neighbor came over with what looks like a hoe but
it is really a flat scraper. She told me to boil some water and throw
it on the floor. After letting it sit there for a few minutes, under
the hot boiling water, say, 5 or 10 minutes, the glue becomes softer
and more pliable....and only then, one is able to scrape it off.
Unbelievable! No chemical would remove it....no machine would remove
it (it just made the coarse sandpaper one goey, sticky mess), but hot
water did the trick! I then, used the $17.00 heavy-duty hand blade
scrapers that I bought at Lowe's (I would say that this was the only
great purchase that I made).
I thought to myself, I have to share this
with everybody, with someone else who is trying to do the impossible,
who right now must be yanking their hair out in frustration, or
banging their head against the wall. This WILL WORK. Believe me, don't
waste your time and money buy going to the hardware stores to buy more
chemicals because they won't work. I used a wire brush in some spots
and that helped also