Wallpaper and Wallcoverings - What is this behind the paper backing?

HELP!!! I am taking down wallpaper.... the paper and backing came off easily with scoring and TSP. Underneath the paper backing is a layer of something that will not come off. When I steam it, it peals (VERY SLOWLY) from the drywall. When I use DIF, it scrapes (VERY SLOWLY). It is a large room, and These two methods are just not reasonalbe. Any ideas on what this is, or how I can remove it??

Please describe what this layer looks like, color, texture, etc. Also, what does it look like underneath? Are these drywall, or plaster walls?

These are drywall walls. The coating is a very light gray/white. When wet, it is sticky. When it is dry, it is very frail.....it breaks up into pieces. When I steam it, I can peal it off the walls...but VERY slowly because it dries VERY quickly (within minutes). When I use DIF, there is a very small window as to when I can scrape.

I think I have it, but one more question:
Underneath this layer, does it look brown, like a grocery bag?

Yes!!!!!!!!!!!!!!!

Ouch, that is what I thought.
:alarm: STOP!!! You are removing the top layer of the drywall.
This is something you definitely don't want to do.
How much have you taken off already?

AHHH! Really??? I have taken off about half of one wall and some bits of another. What should I do????

Stop, and let the wall dry. Then sand it with 120 grit paper or screen. Don't try to sand it all smooth, just enough to knock off the high or loose areas. Wipe off all the sanding dust, and prime the walls with an alkyd or oil based primer. Then you need to float (skimcoat) the damaged areas with joint compound until everything is flush. Sand smooth, and remove dust again. Very important to remove all the dust, as this is the number 1 reason paint will fail. Reprime the skimmed areas with either the same oil, or an acrylic, and you should be ready to paint.