Cause for Damaged Tile over Concrete

It looks like years of damp concrete which causes effervescence of the lime in the concrete mix. It could be damp from ground water, poor drainage at the gutters, or high humidity. The "bubbling" is also consistant with water infiltration over time.

Make sure that your gutters are in good condition and your downspouts transport all the collected water at least 3 or 4 feet away from the foundation. Sometimes the backfill is very porous (as in crushed rock) and that takes water directly to the slab in the lower level.

It is important that there is good air circulation or a dehumifier to keep the moisture low in some cases. The last thing you want is a damp rug. You may need to drill a small test hole through the concrete to make sure there isn't a pool of water under the slab. This is more likely if the surrounding ground is higher than your lower level.

The concrete pad below the flooring may be cracked, allowing water to seep in from below. The crack may be due to settling. I had a similar problem about 15 years ago in my previous house built in the mid-70s. If so, you'll have to have the crack fixed. Just part of the fun of home ownership. You might talk to a contractor that does basements and ask about it.

Thanks for your reply. Once we remove the tile and mastic, will we be able to see any cracks in the concrete?

Cracks should be visable through the old tile.

After it's all cleaned and patched and in good shape, you could: Concrete Floor Grinding and Polishing - YouTube and use rugs.

This looks totally normal for a 50 year old floor.

Yes, moisture intrusion may have shortened the life of the floor, some, but, what do you expect from tile and adhesive that are 50 years old and made from the materials of the day.

I would go with ceramic tile rather than carpet....

You could save a lot of money and possibly your health, by not disturbing the asbestos flooring. Just remove the loose stuff after wetting it down. There are better ways...

http://www.familyhandyman.com/DIY-Projects/Indoor-Projects/Basement/Basement-Finishing/how-to-carpet-a-basement-floor/View-All

Just mop it down with bleach, rinse mop it a couple times and tile right over it. If it stayed down that long the guy who installed it did it right. Makes good insulation too!

I agree with the guys here. If you disturb the tile, you're asking for an asbestos problem. Get the tile wet and remove the loose pieces. Fill in the voids with a floor leveler - in fact, I'd do this over the entire floor, so you have a good base to start with. Make sure the old tile is clean before using the leveler.

If you plan to tile the floor, I recommend a porcelain tile vs a ceramic one. The price isn't much different. The labor to install is nearly the same. You will need to cut the tiles, which is a little harder, but a standard wet tile saw will do the trick. Also, but a porcelain tile that is the same color all the way through. The cut edges look better and if the tile cracks, it's much harder to see the damage. Home Depot tiles are not as well made as the ones from Lowes. If you're inexperienced, I highly recommend your local tile store. They'll tell you about the quality differences, their selection is better, they'll give you advice, sell you the right thinset, spacers, tools, sponges, sealer (for the grout only) and the right grout color. Plus, you're supporting a local business - a major plus!

I have owned rental property since the late 80's and I've found that porcelain tile is the way to go. Remember that the labor is the expensive part of tiling and when you do it right, it looks phenomenal. When you make minor mistakes, it still looks good. If you blotch it up ... welll

If you are sure it is asbestos, then you should use a licenced company to remove it if you ever expect to sell the house. Worth the ridiculous high price of removal just to get that certificate.

Once it is gone, then apply thin set and stone or ceramic tile. I prefer stone because it can wick moisture out from under, whereas ceramic is pretty much impervious. (depends upon the stone of course...I am thinking of slate.)

Last time I faced this problem, the home owner elected to simply remove the floor as well as the tile....but there were a LOT of other issues with that floor....cracks were letting in radon and sewer smells. If there are other issues with that floor, it may well be worth it to simply jack hammer out the floor, lay down an impervious membrane, and re-pour it. Often the floor is only two inch concrete, and will break up pretty easily. Just another option.

"We are planning on removing this floor (using a licenced asbestos abatement company). "

Why not read the entire thread before jumping in with useless, unneeded advice??

At least three people have needlessly admonished the OP for something they never intended to do, remove the floor themselves.

From the marks on the floor it looks like the previous owners dragged heavy items over it and chipped edges- if you are using a certified asbestos remover I see no problems but to be sure I would seal the concrete under before laying other tiles.

As was said, it looks like normal wear for VAT of that age. I would not mess with it. Think about finding a contractor who will topcoat the entire floor with a product like gypcrete or other material that will work in a thin layer. Totally encapsulated ACM is legal to have in a dwelling and an inch or two of cement is total encapsulation. At least it was when I was in the business 15 yrs ago. More cost effective and safer than removal.

My experience is to never use carpeting on below grade concrete floor. Just the moisture condensing on cool concrete will lead to mold and mildew. Go with the ceramic tiles. You will have beauty, clean atmosphere and you can always use some area rugs in decorating just keep an eye on moisture especially in humid summer time. If you have cracks and wish to seal use the resin injection method. Worked for me 100% in sealing my underground home I built.

What do you know about construction of the original floor? I have learned when looking at garage floors for storage of antique vehicles, that concrete MUST be poured with a vapor barrier UNDER it. The concrete may not let liquid water thru, but it will let water vapor thru. Even several inches of concrete will let water vapor pass thru it. I think one test was to tape a piece of plastic sheeting to the floor, and see if it gets condensation between it and the concrete after a couple of days. The vapor barrier knowledge may not have existed when this floor was done, and being below grade certainly subjects it to damp, if not wet, conditions below the floor. Therefore, I suggest you put down a vapor barrier then cover that with a layer of concrete (or whatever). This would also encapsulate and eliminate need to remove the old flooring.

Concrete will let liquid water through it. I have a basement in Minnesota to prove it. It floods if I don't run a dehumidifier all the time (or a sump pump), in the summer months.

My favorite flooring has always been poured floors. Years ago my Dad and I poured an acrylic floor over an existing asbestos tile floor in our split level home on Long Island NY built in 1954. It consisted of a color base pour which sealed all cracks and damage between existing tiles. We then applied a decorative layer which consisted of color chips randomly dispersed. This was Mothers idea and Dad and I didn't really care for it. Then the final stage was a clear acrylic top coat. This presents a fully sealed, level and extremely durable floor. This was back in the 1960's. Advances in materials will make this an even better idea, but I have no personal experience with current products. A quick search showed a few rather attractive options which I will share the links to.:

http://services.vivastreet.co.uk/handyman+durham-dh1/poured-floors-poured-flooring-poured-resin-polished-concrete/31955053

http://dur-a-flex.com/Home/FlooringGuide

Now that you are completely confused by the vast number of possible solutions let me summarize...

For the price of removing a very well installed floor tile that you have and that is impervious to practically anything, you can install the best porcelain tile Lowe's has in stock. Do it in this order:

1. Scrape the floor with any sort of scraper you want from a 6" drywall knife to a long handled floor scraper. The asbestos in the tile won't hurt you, it's the dust in the air that will so wear a cheap white mask like they sell at Lowe's.

2. Vacuum the floor thouroughly with a vacuum that has a bag in it and throw the bag in the trash when you are done. (You are still wearing the mask.)

3. Bleach mop the entire area with a mild bleach solution to kill all the mold, etc. that might have accumulated over the years. Rinse once.

4. Buy the ceramic tile you like and the bags of dry thinset and a notched trowel, and a chalk line with blue chalk which is also from Lowe's. Also buy a little bag of the cross shaped silicone spacers in the size of the grout lines you want. I like 3/16" ones. Don't give in to temptation and buy the pre-mixed thinset, it is water soluble, unlike the dry thinset which is cementatious in nature and impervious to moisture once it is dry. Knee pads are a luxury you might want to indulge yourself with, too.

5. Mix up some thinset and use the smooth un-notched side of the trowel to fill in any voids in the exitisting tiles that may have been produced by the scraping process. Make sure your in-fills are flush with the surface of the existing tiles.

6. Now measure off the longest wall from each end out a distance equal to one of the tiles and strike a line from one end of the room to the other. Somewhere along this line make two marks 8 feet apart. From one of those marks measure out towards the center of the room 6 feet at approximately a right angle and with someone holding your tape measure, draw an arc about 6" long. Have the person holding the other end of the tape move to the other mark and extend the tape out to 10' and draw another arc so that it crosses the first arc.

Then take the chalk line, have the other person hold it on the first mark on the original line and pull it all the way across the room while making sure it crosses the center of the X created by the two small arc lines and pop this line. This will give you a perfect right angle to lay your first row of tile to.

7. Start laying your tile from where the two chalk lines cross using the notched trowel to spread the thinset. Hold the trowel at about a 45° angle to the floor so that you have a pattern in the thinset that looks like a freshly plowed field. Don't cover your chalk lines, just put the thinset right up to them. Spread enough for two tiles at a time. Lay your tiles carefully on the ridged wet thinset and tap them lightly so they are level. Fill in the entire floor this way, working you way out towards the door. :)

8. Let the tile set up over night. The next day (assuming you got it all laid the first day) you can grout it with a rubber faced grout trowel which you can get also from Lowe's when you buy the color grout you want. The grout sets up in an hour or two to walk on but takes overnight to get really hard.

Clean the grout as you go about 8 tiles at a time with one of those big yellow sponges in the tile isle. Dampen the sponge and wring it out good and don't press down when you are cleaning it. Just let the sponge ride over the top of the freshly grouted tile so you don't remove any of the grout from in between the tiles, just from the surface. Gently clean all of the excess grout from the tiles as you go since once it dries it will be hard to remove without soaking the entire floor with white vinegar for 20 minutes the nest day to get it loose.

You're done!

I think that Ordinary has got it right - although this is manifestation is usually called "efflorescence" - not "effervescence." The slab is wet periodically where this effect transpires.

Check to see if the symptom is general over the floor or confined to one area. (The latter is almost certainly the case). In my case it was a compromised shower stall.

If it is along an outer wall it will probably mean intrusion when raining. The foundation wall - as previously mentioned - should have weeping tile at the base of the wall; in your case 3 feet down from grade. The wall should have a membrane applied to the outside. This membrane may be missing or compromised.

The fix is to dig down, repair or replace the weeping tile and repair or replace the membrane.

How you choose to deal with the asbestos is another matter.

I occurs to me that there is a cheap alternative you could try. Since you propose to lay indoor/outdoor carpeting you could try to stop the intrusion of water by waterproofing the affected area with a slab sealer such as Xypex.

I can't figure out how to insert a hyperlink so you will have to look this up yourself.

Another such product is "Vandex".

These products leave a granular finish on the slab - but that would be OK if you are laying carpet.

This would be a gamble - but it might work.

it probably happened due to water being held under the tiles,if this happened once it might happen again and it probably would be safer to use tiles instead of a carpet, anyways make sure the concrete is dry before proceeding with additional work after you have removed the existing tiles