On Sat, 2 Jul 2016 14:57:45 -0700 (PDT), Michael Wilson
wrote:

On Saturday, July 2, 2016 at 4:43:37 PM UTC-5, bob haller wrote:
On Saturday, July 2, 2016 at 4:01:13 PM UTC-4, Michael Wilson wrote:
That is the question.

I'm going to take out the carpet from our living room and install tile. The subfloor is 3/4 OSB. Can I just put tile backer board on top of this or not? If so, should I go 1/2 inch instead of 1/4? I see a lot of conflicting information about this. Most say it's ok, but we talked with the Home Depot guy and he insisted it needs to be plywood. What thoughts?

Thanks!

Mike

if your installing ceramic tile use concrete board and mortar the joints. be sure the cement board joints arent the same as the underlying osb joints

We saw some porcelain tile we liked, but it's ok to use concrete board over OSB? I'm not sure why the Home Depot guy was so insistent that that was a bad idea.

Thanks,

Mike
Because it's a bad idea. Not saying your installation WILL fail, but
the chances of success using OSB will be significantly lower rhan with
plywood - and just putting plywood over the OSB is not quite as
effective as replacing the OSB and doesn't raise the floor level as
much.