Another One For The Tilers.

[needawin]

I have just removed the tiles from a concrete floor.
underneath are the ridges of the 'adhesive'. Ridges that are as hard as iron. what tools ar best for removing then. Spade or something maybe?

[Mamyalynne]

A couple of answers earlier mentioned an angle grinder, probably your best bet.

https://www.theanswerbank.co.uk/Home-and-Garden/Question1698078.html

[KARL]

There exist machines that are in effect like angle grinders with a "cup" fitted, the cups having ridges on them. Crucially, one uses an industrial vacuum cleaner with the end of the hose connected to the grinder - almost all the dust is sucked away (otherwise you fill the house with dust). Other methods are a light year or two away by comparison of effectiveness and/or effort. Maybe you can hire one of these from a tool rental business near you.

[Ryzen]

Spade..then bolster chisel..then grinder...then floor levelling compound. Bet you wished you had listened to The Builder now..dont you.:-)

[Melvinimo]

Usually, such glue is removed with a punch with a special nozzle, but to lay a new tile, you need to know how to set the levels, you will learn about such tools from the blog https://best-workshop.com/top-4-the-best-tile-leveling-systems/, which details everything you need to know about tile laying.