Need to Level 8' x 8' Floor with 1 1/2" variance - Contractor Talk - Professional Construction and Remodeling Forum

highpeaks · 03-23-2009, 05:37 PM

I'm renovated a HO space for a new bathroom. Existing sub floor looks like 3/4 slot sub floor with another 3/4 T&G on top. The floor drops about an 1 1/2 from one end to another. What is the best way to level and provide a strong surface for tile. I had cut down 1/2 and 1/4 8 foot shims. I was going to try running shims over the joists and then run new 3/4 TG perpedicaular. Then hardibacker , then tile. Will the 3/4 over shims give me any problem with tile.? What about using DITRA?

macatawacab · 03-23-2009, 09:31 PM

why not a layer of patching cement used like self leveling concrete? mark your levels around the perimeter, pour to the line, and float it out with a bull.

then your Ditra would take out the small imperfections.

AboveAndBeyond · 03-24-2009, 12:03 AM

i second the self-leveling concrete! tough when the floor pitches toward the door however. i've never had the need to use ditra with it either. though, be sure there aren't any holes for the stuff to escape through (toilet flange?) i larned that the hard way once, ha.

Bill_Vincent · 03-24-2009, 12:25 AM

I'm also on board for something like that, even before I read the other replies. If it were me, though, I'd be using a type S mortar, instead, though, and I'd be using thinset as a bond coat, and float from your deepest point to nothing at the high point.

highpeaks · 03-25-2009, 11:48 AM

I thought about a self-leveling pour, but I was concerned with the feathering at the thinest point. I still need to lay tile on top. Do you thin the Ditra will work fine at the thin-areas where there's only ply?

kevjob · 03-25-2009, 12:17 PM

If I have acces to joist we will sister a joist of similiar or close to that size next to it and use the new joist to make everything level. if not use self leveler and make sure you use the primer.

plazaman · 03-25-2009, 03:55 PM

many ways.. all depends on the budget and type of job. low, highend, mid range..

we've done everything from self levelers, plywood & 2x4 where you slice down the 2x4, sistering to a level, mud bed and float out entire floors, level out with thinset when laying tile (small areas) to house jacking

Rob79 · 03-25-2009, 05:05 PM

It is more money than self leveling cement, but the best way to do it is to tear everything down to the joist and start from there. You always get a better job to start fresh than to keep adding to the floor. Just remember to run full length 2x material(not just shims), or sister in different joists. Make sure you use 3/4" t&g ply along with ditra.

72chevy4x4 · 03-25-2009, 10:46 PM

you already have 1.5" of subflooring and want another 3/4" plus 1/4" cement board plus tile...that's an awful lot of weight! leveling compound from 1.5" to 0" should do the trick then thinset and hardi (or your choice).

kevjob · 03-25-2009, 11:52 PM

Quote:

Originally Posted by 72chevy4x4

leveling compound from 1.5" to 0" should do the trick then thinset and hardi (or your choice).

how do you attach the hardi over the slc?

Bill_Vincent · 03-26-2009, 08:45 AM

neolitic · 03-26-2009, 09:10 AM

If the floor got that way
because it was under-framed,
will it even handle tile?
My first question would be,
"How'd it get this bad?"

Floordude · 03-26-2009, 03:53 PM

Quote:

Originally Posted by neolitic

If the floor got that way
because it was under-framed,
will it even handle tile?
My first question would be,
"How'd it get this bad?"

Exactly what I was thinking. The structure is going to be crying when all that weight is added.

Bill_Vincent · 03-26-2009, 03:57 PM

That's why I posted the stupid look last post. I MUST be slipping! Sometimes you just can't see the forest because the trees are gettin in the way!

neolitic · 03-26-2009, 04:24 PM

By my count, two floor guys
had already gone over this mess,
and she had a guy ready to tile it.

Bill_Vincent · 03-26-2009, 06:00 PM

Piece o cake.

kevjob · 03-26-2009, 06:16 PM

looks like all my bathrooms I do and when people see after the demo I get alot of these

looks.

highpeaks · 03-28-2009, 06:58 AM

The floor got that way by bad framing. We are sistering up all the 2x10's, In addtion, we already poured a 10' footing in the basement for a bearing wall to support the joists mid-span. THis will help reduce the load. I was think about removing the sub floor in he 8x8 area that will have floor tile. I would rip down to the joists and then level the floor using the new sisters joists. My only concern was weakening any adjacent areas that still rest on the old subfloor and joist system. The old joist span is about 15'. Otherwise with the new support system I thought that an SLC would be just fine with the added wait.
Any recommendations for an SLC the I can pour the deep in one shot?

highpeaks · 04-02-2009, 04:59 PM

So here's my delema. I want to use Level Quik SLC. It's not recommended over T&G plywood. They want it to be exterior grade. So they recommended that I put down 1/4 wonderboard over the ply bonded with thinset and screws. Then primer and then pour slc. My other option is to pull up one layer of the t&g . Replace with 3/4 CDX. Primeer, then lathe, then pour.

Obviously each one is labor intesive. Not sure which is best method. Or ar ethey about even. Thoughts?

neolitic · 04-02-2009, 06:06 PM

Most of the T&G plywood I've seen
is exterior grade.