Here's what you need to know. As a whole you can install tile on an uneven floor, what you need to do first is apply a layer of levelling compound. It will fill in any gaps, and go hard like concrete. You use a trowel to spread it out and make it flat and even.
Before installing tile on your floor you must make sure your floor is properly prepared. A properly prepared floor does not have to be level. It must, however, be flat.
Linoleum sheets and tiles both work well on uneven surfaces, but you'll likely find linoleum a bit trickier to work with, and it will need sealing when finished to resist water. Although both linoleum and vinyl will work on an uneven floor, they won't hide the unevenness like carpet will.
As noted in the first answer above, the surface to be tiled, in your case the floor, must be flat within 1/8” in 10' when measured from the high points of the floor. To achieve this, be sure to use the appropriate patch or self-leveling compound (with the same manufacturer's primer), but never thin set mortar.
If you're tiling a really uneven surface, sometimes the best solution is to opt for mosaic tiling. This involves using much smaller pieces of tiles of various shapes to create a well covered wall that minimises the effects of an uneven surface.
Once level and the mortar has dried, start laying the tiles. Place the spirit level flush against each tile when applying it and with the help of a mallet, push each tile in until it is level. Once you're done with that, use a leveling kit. The kit comprises of two parts.
You can use thinset to install tile over an uneven cement floor and leave the floor perfectly level. You can also use thinset mortar to level out an uneven cement floor or fill small holes in the floor without installing tile.
Because concrete floor surfaces frequently have small dips and hills, they must be leveled before installing tiles on them. Using a self-leveling floor compound will help ensure that the concrete is completely flat before you lay the tiles.
When a tile is pressed to this thinset, it spreads to fill the spaces between the ridges, resulting in a thinset layer 3/16ths of an inch thick.
If you're considering purchasing a home with uneven floors, don't wait to investigate the potential issues beneath the home's surface. The slope or slant of the floor may be a minor cosmetic issue, or it could indicate water damage or major problems with the home's structure or foundation.
Building codes governing framed floors include an allowance for sagging, which sounds bad. But the allowable limit is 1/360 of the span, which isn't much.
On average, you are looking at about $3 – $5 per square foot. So, for a 100 square foot slab, it would generally cost between $300 and $500.
Tile installation requires grooves in the thinset to create air pockets which facilitate the adhesion of the tile. You can use thinset to level the floor if its only out a little as you say it is (no more than 1/4).
Portland self leveling cement is a type of pourable cement that is primarily used in the preparation of interior floors as an underlayment to support new floor covering installations. As the name implies, it "self-levels' because of it's relatively thin consistence.
Using thin set to fill low areas by applying it a little thicker (most times it is much thicker) as the tile is being installed, is not a good idea. In fact, most manufacturers indicate in their product literature NOT to use thin set mortar to level or flatten the floor or wall.
According to Wiktionary, lippage is "an uneven surface of a floor that occurs when stone or tiles are not laid to a uniform level." If you look at the image above, notice how some tiles seem higher than others? That's an extreme case of lippage. The tile planks don't form a flat surface.
The cheapest way to level a concrete floor is to use a specialized sand mix. This sand mix is 90% more affordable than self-leveling concrete while producing similar results. To do this, you will spread the sand mix across the top, spray it with water, and then let it dry.
Thin bed adhesive should be 3mm thick when the tile is adhered. Thick Bed - Use a 10mm to 12mm notched trowel for surfaces that have a greater than 6mm variations over a 2m length or use the solid bed or buttering application. Thick bed adhesives should be between 3mm to 12mm thick when the tiles is adhered.