Tiling bathroom floor. Floor out of level. Not sure what to do next.

[averwo]

My wife and I are redoing our bathroom. We thought we had the floor level when we put cement board down. But after we put the tub in we found a small gap were the tub meets the floor.

I thought we would be able to slide a small piece of 1/4 inch cement board under tub in the low spot and then mud everything level when we tiled. But we found out that it was going to take a lot of mud and it wasn't working out well.

I'm not sure how to proceed. Can I slide the piece of cement board under the tub on the low spot and then poor leveling cement around it to fill in the low spot on the rest of the floor?

I have included a picture that shows where the low spot is under the tub and in the middle of the floor. I out lined it with a line.

I'm sure we did everything wrong. Nothing has gone right in this remodel so far.
My wife and I are novices and probably should have hired a pro so please be nice!

[CountryBumkin]

It looks there is a bulge (high spot) where the two sheets come together. Is this a photo illusion, or do you have a high spot in the middle of the floor too?

[ZZZK]

Also is there thinset under those boards?

[Kman]

Is this a dip in the floor that you're referring to? If so, how deep is it?

Use the longest straight edge to find the dip in the floor, or use a string.

[averwo]

There is no high spot.

I didn't use thin set under the cement board. Just screwed it to the plywood. Is that bad? I used lots of screws. It's permabase so I screwed where they X's were and put more in for good measure.



The low spot is were the red circle is. It's about 1/4 inch at the lowest spot right under the tub skirt.

[ZZZK]

The permabase needs to come off before you proceed. No amount of screws can make up for the requirement to float the board over thinset. Every CBU including Permabase requires this in their instructions for floor installation. The purpose of the thinset is not to hold the board in place but to fill all voids and undulations in your subfloor so that the board is fully supported across its entire area. They also require that you fill and tape all board seams with thinset in order to lock those two potential planes of movement together. A step I also see you haven't done.

That installation will very likely fail the way you have it.

[rmckee84]

One thing I'll add is, did the directions for your tub/shower call for a mud or sand bed under the unit for support. Many times that is skipped over and it seems they make these units cheaper every day and without it you risk having too much movement causing it to crack.

[averwo]

One thing I'll add is, did the directions for your tub/shower call for a mud or sand bed under the unit for support. Many times that is skipped over and it seems they make these units cheaper every day and without it you risk having too much movement causing it to crack.




I don't know how to quote peoples reply's on this forum. There is no reply or quote under every post. Anyway.

No. The tub did not say to to lay a bed of mud down. There is a piece of plywood and 2 wood feet that support it on the floor.

[Houston Remodeler]

Dave,

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