HOW I SPENT MY SUMMER, by Steve
I removed wallpaper from every room of a 1650 sf house.
I learned the following:
The only "wallpaper removal tool" that is effective is a paper tiger, a scraper, and a sprayer. And time.
There are different types of wallpaper. Some you can spray with water, and it will peel right off. Some, like in kitchens and baths, has a foil or vinyl layer that doesn't soak in the water, and is harder to get off.
Time and patience works best. Spray, wait a couple of minutes, peel or scrape. Repeat. Repeat. Repeat. Spray ahead of yourself so that some is soaking while you are scraping.
Use hot water in a sprayer, either a pump up or hand sprayer. Take your DIF back for a refund. It is worthless, and works just as good as plain hot water. The glue originally had water in it, not DIF. Spray and wait. Use a paper tiger, but only on the stuff that doesn't take on water. It it does take on water, the small cuts keep you from peeling off any big pieces. On a couple of pieces of absorbent paper, I pulled off the whole strip ceiling to floor. Use a scraper. I tried several types, and the thing that worked best was an old spatula that had a steel flat surface and a wood handle. Get the feel of when it is working, and when you are gouging. I think the springy handle kept me from gouging, and I definitely could "feel" it better than when I used a real scraper. BTW, I liked the plastic scrapers best.
Remember this: you are trying to get water into the glue layer. When you do, it will turn to snot, and release the paper. Until then, it acts just like glue. And there are different types of wallpaper glue. Some comes off easier than others.
Work on small areas, getting all the paper off before moving on. You can spray larger areas, but I wouldn't go bigger than three feet wide. After you get the paper off, sponge the area or wipe with damp rags so as to get the residual glue. Do this more than once, letting the wall dry between times. Look down the wall to see if you have it all. This is critical in getting a good surface to paint. If you have a helper, you can work in layers, one taking off the first wave, the second coming behind to work on the leavings, and the third etc. It is good to work on a wet wall start to finish to take advantage of the wetness. Then let it dry if it starts getting too wet. Let it dry to do another wiping to remove the glue, because there is a time when both the glue and the paper on the wallboard will come off together if it has gotten too saturated.
Spray. Wait. Peel or scrape lightly. Repeat. Watch for the shade when the paper comes off, and wait until the water has soaked into it to make that shade. A lot of time, the surface of the paper will come off, and then the under layer will have to sit with spray on it for the right amount of time. When the underlayer is totally saturated, it comes off easier.
Lastly, there is no easy way to do this. There are just tips. It takes a LOT of work and a LOT of time. There is no quick and easy way except to hire it done, and that doesn't shorten the time.
If you want a good paintable surface, you have to do it slowly or you will either gouge it up or pull off the paper on the wallboard. Or just wear it all down, and have to retexture.
You will get a rhythm going, and will recognize when it is ready to be scraped off easily. I think the most important thing to do is wait for the water to do its work. Put towels along the baseboard to get the excess water.
Fun it ain't. A guy told me he would do it for $800, and I thought that was high. I wouldn't do it for $800 now that I have done it. But then, I don't know if he would have done as good a job as I did.
Steve