How much of the adhesive do I have to remove before I lay slate down in the kitchen?

I'm redoing the floor in my kitchen with 12x12 slate. I pulled up the old vinyl floor, and when I did, it left all the adhesive with a top layer of gray paper. Can I just put the mortar over this, or do I have to physically scrape up all that adhesive/paper?? I've tried an adhesive remover already, and its not coming up very easily at all...How much of the adhesive do I have to remove before I lay slate down in the kitchen?
If your subfloor is wood, then just put down some 1/4 or 1/2 inch tile backer board to cover the adhesive. Making sure to screw it down as recommended ( about every 4-6 inches) then you can use mortar and set your slate.





If your subfloor is concrete, Then you should remove all of the adhesive. You may need to see about some stronger adhesive remover or re-apply what you have. Once you have the adhesive removed, then you should wash the concrete with muratic acid and water -- about ten parts water and one part acid. Always add the one part acid to the water not the water to the acid - water added to acid will cause a cloud o gas that is harmful to breath.





Again if the subfloor is concrete and you can not get the adhesive off using remover and some muscle with a scraper, then you may have to grind it off. Unless you rent a professional floor grinder, your other option is to use a body grinder (7';) or a smaller one to do this. Problems with using these are the dust they will create and that you will probably creat more work for yourself because the grinder will make small dips and gouges in the subfloor - that is unless you have a lot of experience doing this and have a professional grinding wheel which I will assume you do not since you are asking for help here. If you do grind the glue off, when you are finished, I'd still recommend washing the floor with muratic acid to ';etch'; and clean the floor before setting the slate.





Removing old adhesive is never a fun project, but a necessary one if you want your new floor to last. Most of the long-term beauty of a new floor leis in the quality of the preparation - poor preparation and the floor will show it over time with loose tiles and crumbling grout.





I hope that this answered your question. Good luck with your project.How much of the adhesive do I have to remove before I lay slate down in the kitchen?
A quality installation would call for removal. You can rent a floor grinder from your local tool rental place or Home depot or lowes for 4 hrs. You have to get down on your knees, hold the big silver devil in both hands, (wear a dust mask) but it will shred that crap off like it wasnothing. Your arms will be tired, but the job will be perfect. No tiles sticking up, cornere higher than others, bad grout lines. A good base equals a nice tile job.


Then a really good vaccuming before laying out your chalk lines, laying down your thinset, and setting your slate.
You can, but shouldn't mortar over the adhesive. Your best bet is to scrape as much off as possible before installing. You need to have as flat a surface as possible to work with so there are no gaps between the mortar and floor and mortar and tile, otherwise it will make a hollow noise when stepped on and compromise the strength and integrity of the tile. Then you will have to replace broken tile and re-grout, leading to inconsistencies in color.All the work will be worth it in the long run.





Good luck!
So long as you've got 1'; diameter hole every 3'; apart, you can continue to screed the floor with mortar.





Alternatively, just drive some nails into the floor leaving about 1/4'; to 1/2'; of nail above the floor, then screed to above that level. That should secure it well.