laminate flooring question

[jlake1998]

Is it ok to use OSB under the laminate flooring or should i be using mdf?

I am going to be installing laminate flooring and tile in my house. Currently its carpet and vinyl.
I want to ensure where it transitions the heights are close to the same. Im guessing i have 1/4 laminate under the vinyl and figured i would be removing that (12 yrs old).
Im planning on installing hardibacker (1/2") under the tile raising that area. My question is on the area that will be laminate flooring can i use OSB as the subfloor or should it be MDF? The base is 1 1/8 cant remember if its OSB or plywood.

[jAngiel]

I am no expert but particle board or plywood is what they typically use for an underlayment, I have seen them use OSB too. I have never heard of anyone using MDF as the underlayment. Although if by MDF you actually meant the coarser particle board, then yes, you can use it for an underlayment.

[crokett]

I don't think I'd use MDF. I'd go with OSB or ply, or at minimum particle board.

[Ed62]

I used plywood on mine, but I think OSB would work too. The only problem I see with OSB is if you should somehow get a lot of water (flooded) on the floor. If it leaks down to the OSB, it will likely swell and become weak unless you use the new stuff that accepts water. Best choice IMHO would be ply.

Ed

[jlake1998]

Thanks for the help everyone ,, I will be using then OSB or ply, hard to steer away under 6.00 a sheet for OSB.

[scorrpio]

Whatever you use, I suggest putting in underlayment and taping it sealed. I put SilentStep 3-in-1 in kid's room before installing the laminate, and it feels very nice. And not worried about spills now.