When laying laminate flooring , it is important to have a level subfloor to lay it on. An un- even subfloor will cause the laminate flooring to be uneven and may cause cracking or bubbling in the laminate .Levelling compound can be used on both concrete and wood sbbfloors ,but the subfloor must be stable before it is applied because levelling compou- nd does not add stability to the floor .Make sure that the subfloor is stable before applying the levelling compound .
Prepare the  Subfloor
Step 1
Sweep the subfloor before so that it is free of sebris and mop it to remove all of the dust .
Step 2
Mix the levelling primer and paint it onto the floor .Make sure that the primer covers every part of the floor so that the levelling compound will adhere to the floor .Allow the primer to dry .
Step 3
Run a straightedge over the floor and look for depression in the floor .Mark the edges of the depressions in the floor .Mark the edges of the depression with a pencil or pen You will only pour levelling compound into the depression in the floor .
Apply the levelling compound .
Step1 Read the directions for the levelling compound and mix it with water .The compo  -nd   will dry very quickly ,so mix it in small batches if you have large areas to cover. Have everything you need  ready before you mix the compound .
Step2  Pour levelling compound into the depressions you marked earlier .Fill them so that they are slightly overfull .
Step3  Allow the mixture to fan out for a minute and then level it with straightedge. Allow the levelling compound to dry for 12 to 24 hours before install the floor over it .