How clean must the concrete slab be

[ttinman23]

Tore out some flooring in a half bath downstairs. Im steadily scraping off the glue etc to get down to the concrete. Was just wondering how much do I need to get off?..Its patchy looking, not sure if I'm over doing it by getting every dime sized piece of glue off or what.

 

[Snoonyb]

Generally yes, you do not want voids that will affect the replacement product.

 

[Rusty]

Tore out some flooring in a half bath downstairs. Im steadily scraping off the glue etc to get down to the concrete. Was just wondering how much do I need to get off?..Its patchy looking, not sure if I'm over doing it by getting every dime sized piece of glue off or what.

What will you be installing?