Flooring Tile - Thick-set mortar removal

I live in Austin Texas. We are preparing to put down the new Kahrs Woodlock flooring over concrete slab. First we have to remove the tiles. There are two types of tiles to come up. The thinnest tiles have thin-set mortar, and come up with a hammer. The other tiles are about 3/4 inch thick, and lead from the entry way to a sunken living room, and have been set on a thick set mortar. How they poured all these slab heights I do not know, as the area with that tile seems to be about 1.5 inches below the other slab, the thickness being made up with the mortar. The house was built in 1976. The thick set mortar seems to come up with the tile pieces each time I break one, and are making a mess of the edge that drops to the sunken living room. My questions are as follows:

1. What is the best wasy to get this tile up? The books say to use a small jack-hammer, so as not to spoil the foundation.

2. Once I get it up, how do I bring this section of the floor up to the level of the rest of the floor? And how do I handle the transition to the sunken living room? Should I just put in new mortar, and level it? If I put in a concrete-based product, how long woud I have to wait for it to cure before I put in the wood floor? Or, considering that, should I just float in a wood subfloor? My concern is that the concrete below the thick-set mortar may not be fininhed since they knew they were putting in thick-set mortar and tile.
3. Any hints from those who have tackled this before? The concrete on the foundation doesnot seem to be well finished on the edges, and is causing other problems around the perimeter of the sunken living room.

Help?!
Steve

Hi Steve,

You have more of a wood flooring concern that a tile one. However, the mortar under the tiles is called deck mud. Remove all of it and start over, using new deck mud to build back up. You can find info on how to do that at our tile forum. I'm not trying to steal anyone from this site, but we already have the archives built down there.

http://johnbridge.com/vbulletin/index.php

I looked at the postings, and they're all about putting tile back down. I don't think I'd want to put tile down. How long would the mud have to cure before I could put wood over it? Why wouldn't I just use ardex to fill it back in and then put the wood over it within a day? The mud doesn't seem very structural, and even has a hollow sound beneath the tile.

A mud bed is used for ceramic tile. Use the Ardex self leveling . It does come in a kit . Im sure you read it Good luck .

How much does the Ardex cost? their web site says I need about 30 bags.

You need to find a carpet wholesale flooring tools ands supply store in the yellow pages. It is a kit of all the tools you'll need . The curing time should have you set for the holidays. There are othere products simular to ardex such as Mapei. Look into it. I personally love ardex it is a great product.

Well . . . . ,

Deck mud is concrete. You can still use the levelor or the slc over the top. Deck mud is very cheap. Ardex is very expensive. I'm aware you're putting down wood. I'm just suggesting how you fill in a hole. :D

I agree with John.

Fill the big holes with deck mud, then screed with Ardex.

Make sure it all dries!!! It isn't going to dry enough in one day. I'd give it at least a week to be on the safe side.

Moisture is going to reek havoc with a wood floor.

Good points. I guess from a structural standoint, I don't really like the idea of the mud, but cost does seem to be a deciding factor. I can just see the guy in ten or twenty years that pulls it all up and shakes his head at the idiot that decided to have three layer sandwiched surfaces just to lay wood. Seems if I could afford it, taking all the mud, and filling with ardex would be the ideal way to do it. How much does ardex cost? Somebody told me it was about $30 per 50-lb. bag. Their web site says I would need 30 bags to do it all 1.5 inches thick. Ouch. And Mud is $5 per 90-lb bag if I recall. SO it's $900 compared to about $100 since I'd need less bags of the mud.

The cost for the deck mud is much less than that, even. a bag of portland cement (94 lbs.) mixed with 45 shovels of course sand will cover an area of about 25 square feet if you are filling a couple inches, 30 square feet at an inch and a half which is probably closer to the mark. A bag of portland costs about $6 - $7. A half yard of sand is about $10.

Bond the mortar to the concrete by dusting it with dry portland and then wet it just prior to dumping the mud on it. Bonding will eliminate much of the hollow sound. There is nothing wrong with this form of construction. It has been practiced in one form or another since ancient times. The Ardex over the top will bond and strengthen the surface. ;)

Let's talk curing times.
1. Wouldn't you want to let the mortar cure before putting the Ardex over it? If so, for how long?
2. Ardex says it's able to have wood laid over it in 16 hours (walk on it in 2 hours). If you laid it over the mortar, would it allow you to floor as soon as the ardex is cured?
3. Other wise, don't I end up with serial cure times- in other words, I add the mortar cure time to the atrdex cure time, and I have to wait for that long before I can put down the floor?
This is a high traffic area that basically blocks off access to the bedrooms, living room and kitchen.
4. So, if I want fast turnaround time, wouldn't it be better to fill the whole thing in with ardex? I know the cost is prohibitive, but so is living in a hotel for a week.

thats apretty good assumption on you're part,the cure time depending on humidity of course is around48 hours for the deck mud and another 24 to 48 hours for the ardex.Since this is concrete and not wood you are going over i would let the deck mud cure first then pour the ardex and allow to cure at least 72 hours after that,keep the heat on in the house if applicable, to help everything dry up as is should:cool:

OK, I'm back- I talked to the local rep of Ardex, and he says that it should NEVER be used over deck mud. He says that it has to have 6000 psi base, and it has to be primed, so cement is the best. He then told me to call the factory, as that is their position. His claim is that the Ardex will "pull away" the mud top layer as it cures.
Has anybody out there experienced enough of this to tell me he's wrong? I guess I'd like to go the most inexpensive route, and after talking to him, I felt the best bet would be to just take it all the way down to the base concrete, and re-fill the area with new concrete.
Again, I would like to avoid the long cure time of concrete! I just can't see walking around on a concrete slab for 32 months while I wait for it to cure.