Flooring transitions

[mreynolds]

I was thinking about how to finish the floors in my new house. We will use 3/4 T&G OSB for the sub floor. I also know that I will apply some sort of underlayment over the 3/4 T&G so it is opposite the exisiting seams. Here is my question. What type of thickness do I need for underlayment? And how do I transition between a ceremic tile surface and a carpet surface? Do I use all the same underlayment, or should I change sizes because of the material on top?

[Rich]

You can change the thickness of underlayments or provide transitions from one thickness to another. It really comes down to how difficult do you want to make it? From ceramic tile with thinset to a carpet surface - you probably won't need anything under the carpet and use 1/4" hardiboard under the tile with a 1/4-3/8" thinset - then your tile. It should come out pretty close.