Revisions log for question
Is it necessary to level the floor with self-leveling putty before installing laminate flooring?

I am going to install a laminate floor. I bought a 5 mm thick underlayment and foil. But when I removed the old carpet, I saw a large number of cracks and height differences. There is a 4-5 mm depression in the middle of the floor.

Does the floor need to be leveled with a self-leveling filler, or should the underlayment hide all these irregularities? 

• floor
• laminate