# Repairing tile floor



## slownsteady (Aug 29, 2016)

While doing some improvements to the bathroom, we were planning on replacing a couple of cracked tiles that happened recently. When I removed the toilet, I discovered that there were more cracks under the toilet in the area around the ring. We checked for movement in the floor and there doesn't seem to be any flex or movement. So I'm wondering what would have caused the cracks. Did i have the toilet tightened down too much? Was the collar on the drain too tight? if so, why did it happen now after about twenty years after the floor was (professionally) laid?

As far as replacement goes, I have a couple of questions. I don't want to mess with the collar cuz that may open a can of worms. So I'm planning on cutting the tiles around the collar and using spare tiles cut to match. I think it would be easier to make square cuts instead of tapering a round cut. Is that a good way to go? They would be hidden under the bowl. 
And do I use grout to seal those seams?


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## nealtw (Aug 29, 2016)

The plumber here always cut a ring out of 1/4" plywood to fit under the ring to bring to that height without having the tile under it. When you get the tile up check the floor for stiffness.


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## kok328 (Aug 30, 2016)

definitely something going on under there.
possibly hollow around the drain pipe cause it looks like toilet sank and crack the tiles.  Pretty sure you would have cracked your toilet or pulled the bolts through the flange before you would crack the floor, by overtightening.


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## nealtw (Aug 30, 2016)

I would sooner see the flange low and use bigger wax so you know the toilet is sitting on the floor and not on the flange.
Have been under there to see the cut floor joist.


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## slownsteady (Aug 31, 2016)

I don't think I'm going to find any cut joists or anything like that, as i had the subfloor off when we rebuilt this bathroom....although that was 25 years ago. If there was water damage recently I should be able to see some flex in the floor when I put pressure down near the flange, which I have tried. But I will know for sure when I pick up those tiles.

While the subject is open; 
1) any suggestions of best way to get the grout removed and how much cleaning to do underneath the tiles? 
2) I'm planning on cutting the tiles around the flange square in order to make the new tiles easier to fit and install. Is that a good idea?


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## nealtw (Aug 31, 2016)

all kinds of toys to remove grout.
https://www.google.ca/search?q=remo...hezOAhUB22MKHdoUAW8Q_AUICSgC&biw=1682&bih=835

clean under tile with hammer and chisel


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## nealtw (Aug 31, 2016)

It sure looks like the floor had to flex.


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## slownsteady (Aug 31, 2016)

I went with the angle grinder with a diamond blade. I was concerned that the speed of the machine would want to run away with me and be hard to control, but it cut so smooth that I had no trouble. A utility knife (which was one of the tools pictured..thanks Neal) worked much better than I imagined at separating the grout from the tile edge. The tiles came up pretty clean exposing the plywood subfloor. I will try to figure out a way to measure any flex tomorrow.


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## nealtw (Sep 1, 2016)

slownsteady said:


> I went with the angle grinder with a diamond blade. I was concerned that the speed of the machine would want to run away with me and be hard to control, but it cut so smooth that I had no trouble. A utility knife (which was one of the tools pictured..thanks Neal) worked much better than I imagined at separating the grout from the tile edge. The tiles came up pretty clean exposing the plywood subfloor. I will try to figure out a way to measure any flex tomorrow.



Do you have access to the under side?


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## slownsteady (Sep 1, 2016)

No access underneath. this is a second floor BR. 
There seems to be a bit of a hollow spot under one of the adjoining tiles (I can see it at the edge where one of the broken tiles was). i don't know if it was always like that, or if the subfloor has sagged a bit.
There is very little evidence of water 'damage' on the subfloor...just one small stain.


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## nealtw (Sep 1, 2016)

How many new tile have you?


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## slownsteady (Sep 1, 2016)

I have the orig tiles, still in box...16 I think. Need to replace three or four, depending on a little patch we are trying.


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## nealtw (Sep 1, 2016)

What is the sub floor plywood over? and which way do the joists go


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## CallMeVilla (Sep 1, 2016)

OK, here goes (because we do these kinds of things quite often)  .....

1.  To remove grout, get an inexpensive multi-tool.  Harbor Freight for < $30 with a grout cutting attachment.  Run it inside the grout lines to separate the broken tiles from the good ones.
2.  Drill a couple of holes in the broken tile with a carbide tipped drill.  Using a concrete chisel, remove the broken tile and clean up the grout line being careful not to hit the existing good tile edges.  Clean the flat area for the new tile, removing old thinset.  Vacuum completely.
3.  Apply thinset to the new tile (back butter) and to the floor.  Re-set the new tile with spacers.  Grout as usual.

With the old tiles removed, you can inspect for subfloor damage.  You will have t fix that before applying new tile or you will be back doing this same job all over again


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## nealtw (Sep 1, 2016)

Cast iron pipes?


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## slownsteady (Sep 1, 2016)

supply lines are CPVC>copper. Drain is PVC. Joists are parallel to the wall at the back of the earlier pictures - marked in last pic here. The plywood looks pretty good. The visible part is 1/2 inch. I can't recall if it is doubled or over 3/4 inch. There is some flex in the plywood which i have tried to measure. It's minimal, but it's real. I'll post video https://youtu.be/CZ2teHIhbDE. There is some gap visible under the edges of tiles still in place...don't know if that came out with the grout or if it always existed. There are a few more tiles that are loose but not cracked. I plan to remove and reset them.
The tiles were laid 25 years ago. If I can get them to stick for a couple more years without breaking, I will call this a success. I really can't replace the whole floor right now


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## nealtw (Sep 1, 2016)

It might have helped if the mortar actually stuck to the floor. This is what it should look like
[ame]https://www.youtube.com/watch?v=OMogoJqcn-E[/ame]


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## oldognewtrick (Sep 1, 2016)

Am I missing a mortar bed or backer board?


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## slownsteady (Sep 1, 2016)

yeah, there was some that was left behind, but not much. i tapped it off with a stiff putty knife and a few whacks of the hammer. In one place, it stuck enough to pull some wood up with it.

I think the flex in the floor may be a space between the plywood layers. As I get a few more tiles up, I'll try to put in a few short screws and see if it sucks down the top layer.


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## nealtw (Sep 1, 2016)

Back near the wall, drill a hole but enough so you can see the layers.
Perhaps you covered crap when you did this work that has gotten worse over the years???
So, this is not T&G?//


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## slownsteady (Sep 1, 2016)

> So, this is not T&G?//



Heh Heh.....silly boy.

Nope. This is an add-a-level addition on a ranch. The second floor was put on about 1980 by the previous owners. Apparently, they picked a cheap-o contractor who made a few mistakes. We totally redid this bathroom about 1991. I don't remember the details now, but we had it open to the studs, and I remember we had at least part of the floor open too. Like I said; it held up a good long time.


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## nealtw (Sep 1, 2016)

When you add screws, use screws with 5/8" reach or pre drill the first sheet. then if the screws don't bit you now there is a problem with the floor below.


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