How do you remove old dried Robert 1407 floor adhesive from concrete

Start with a hammer and chisel, when it starts to come up, you can pull them off. Clean the floor and make sure it's level, before installing new flooring. Good Luck!

Start by scraping with a good floor scraper - a good one will be heavy, have a comfortable handle, and will have a very sharp, strong, angled replaceable blade, and works wonders. (I usually try to borrow one from a professional because the best ones are expensive!) After that, you may need to "melt" the remaining adhesive with a solvent - be sure to use good ventilation, and you may need more respiratory protection, and use the scraper again when the adhesive is softened.

If you're going to tile over the concrete, skip the above steps and grind off the glue to open the pores in the concrete so the tile mortar will bond with the concrete. This sounds like hard work, but with the right grinder, it's not too time consuming, and it is imperative for a long-lasting tile job.

If you're going to stain the concrete, it will be difficult but not impossible to get enough of the old adhesive off to get the surface to accept the stain consistently. If you're coating the concrete with an opaque product, scrape and "melt" until you're satisfied with the smoothness of the surface, find out where the pro painters in your area buy their paint, and ask them about the best type of primer and paint for your project-- and follow their advice!

If it's just the adhesive that is your problem try a heat gun on high, but be careful they do get very hot and could even cause a fire. I removed a lot of glue from old tiles this way ...heat, scrape, clean. repeat..... Good Luck!!

A mixture of TSP, lye and water will loosen it up. TSP and lye can be found at hardware stores in dry (powder or granules) forms. Do not use the non-phosphate TSP.