Newbie subfloor question

[71CJ5]

Hello all!

I recently purchased my first home and one of my first projects (first ever tile job) is to get rid of the stick on tiles on top of linoleum. I would like to replace this with basic 12x12 ceramic tiles, nothing too fancy. I tore up the linoleum and this is what I have to work with:

Engineered OSB floor joists that are 16" on center
23/32" OSB sheathing/floor
1/4" USG Fiberock underlayment

The Fiberock appears to be glued to the OSB (couldn't get a putty knife between the 2) and then secured with either staples or brads.

Am I correct in thinking that I need to thin-set and screw 1/4" Wonder-Board or Hardi-Backer on top of all this before I set the tile? Also how much of the linoleum adhesive needs to be scraped up if I go this route?

Thanks in advance

[Tool Guy - Kg]

Welcome to the forum, Joe.

First thing you need to do that's in your very best interest is to examine that Fiberock some more. If that's just stapled or nailed down, it's gotta come out as a lack of thinset under it creates a very real possible liability that will shorten the life of the new tile floor. A flat prybar is much stronger than a putty knife and should tell you how it was installed.

[71CJ5]

Will do!

I've got to replace the toilet flange so that will give me a good seam to investigate. I'll report back later...

[71CJ5]

Well it looks like the Fiberock is just stapled down. Gonna go rip it out right now.

What it the correct thickness of hardi-backer to use on the subfloor? I bought 1/4" but can return it if I need something thicker.

[bbcamp]

1/4" is fine for floors.

[Houston Remodeler]

CBU is applied to the floors with a layer of thinset followed by cbu screws at the proper intervals. An impact driver will be a great investment.

[71CJ5]

Thanks for the info guys.

I will lay down a coat of modified Versabond thinset on the OSB and then put the 1/4 hardibacker on top and screw it all down using the pattern on the board. Then another layer of thin set with my tile topping it all off. Sound like a plan?

[bbcamp]

Don't forget to tape and mud the backerboard joints as you tile!