Difference in Floor height

[MikeJM]

I`ve got a 6mtr x 2.5mtr floor that I want to lay laminate flooring on.
Problem i`ve got is that half of the floor is concrete and the other half is thermoplastic tiles and this end is therefore higher than the concrete by the tile thickness: 3mm.
This is because the room was originally two and had different flooring in each room, ceramic tiles in one which I have taken up without any problems (dont think it was put down too well originally) leaving the concrete floor fairly level, but the thermoplastic tiles have been down since the house was built.
I`ve taken a couple of tiles up which leaves a black Bitumen like surface that I presume was the adhesive. The surface is slightly tacky and i`m unsure as to how to deal with this. I would imagine this could mean quite a bit of work as well.
Is it feasable to lay the Laminate flooring over the different height with a thicker `underlay` on the concrete side of the room to bring the floor level? Or what is the best way to deal with the Bitumen serface?
Any advice please?
Mike

 

[jono_h]

Mike,

Here's my advice. I had the same problem as you - two rooms opened up with slightly different floor levels - laminate floor to go over the top. I paid someone to put some self levelling compound down to even up the surfaces, but it is surprising how little a difference you'll notice when you walk on laminate. It bothers me to this day.

Don't try and make up the difference with thicker underlay. Either use self levelling to make up the tile height (but get a good job done), or take up the tiles (ideally you may still want to self level) and if the amount of bitumen left isn't too great then just place the underlay over it.