I am looking for a flooring transition for tile to hardwood, tile to laminate, and laminate to hardwood. I really do not like the transitions that are raised above the rest of the floor. All of the flooring in my house is exactly flush when it meets. I am wondering if there is some sort of "invisible transition".
Solid hardwood is a tough one because unlike the other materials, it expands and shrinks. Laminate and especially engineered hardwoods with a plywood core are much more stable, but they will still expand and shrink a little bit. Certainly more than tile!
I'm in the middle of installing plywood core engineered hardwood in my own house and I have tile transitions. Here's what I'm doing: I'm leaving a 1/2" gap between the tile and the engineered wood and putting grout-colored silicone caulk in it. That way any expansion or contraction of the wood won't cause it to buckle against a more inert material, but there's still a visually-pleasing material in that transition.
I had the exact same issue after I took a wall out: tile to hardwood. I cut one side with a rip saw and the other side with a wet tile hand-held saw (to keep the dust down). I used an 8 inch wide piece of oak. I stained it to match the floor and then used it as a guide to cut the other side so that it would drop in perfectly. The picture below is after I was done cutting.
Essentially I put my piece of oak wood in the gap & nailed it down with my nail gun. There was less than ⅛ of an inch gap so I didn't even grout or silicone the tile side. I am thinking of mixing some grout with silicone to make the small gap look like it is filled with grout rather than silicone.
Here is the final result:
I was only going to post a comment, since both members covered tile transitions, but I seen that the laminate floor transition has not been addressed. I will also throw my 2 cents on the tile transition too.
The transition to the tile to wood has been well answered by both members above. Ecnerwal eluded to what I will mention. The joint between the tile should be, if not for any reason, big enough to match what is in the tile already. As a testimony to how tight a joint can be, it was proven by Ecnerwal's install. I would still hold it off a bit especially if the tile is in place first, and the wood is installed later. The wood floor will expand a bit, during the first year, after that the wood will move at the gaps created by the initial movement as mentioned by Ecnerwal. I still match the tile joints to accommodate this.
To treat the actual joint, I would use a flexible caulk that is water cleanup. Silicone is supreme for this as mentioned by iLikeDirt, but the clean up can be tricky. Taping either side of the joint can help tremendously, but one missed place where the caulk is not cleaned at the edge of the tape well enough, you may have a mess on your hands, especially after my last detail.
The last detail is this, Using the dry grout dust that was used on the tile floor, while the caulk is wet, sprinkle the dry grout onto the top of the wet silicone or latex caulk. Silicone will start to skin over in 5 to 7 minutes, so you must move quickly. Remember, use a caulk that is a close match to the grout, the dry grout will give it texture and a slight variation in color to help mimic the rest of the grout in place. When using a caulk that is water cleanup, the taping is done as before, but a damp sponge can be used to prep and clean the joint for the dusting. While the joint is fresh wet, dust the joint as above, let dry over nite or longer, and vacuum.
With the laminate floor, first thing to remember is it MUST be installed with a 1/2" space all around the perimeter. It is a floating floor, not secured to the subfloor in any fashion. This is where the problem lie at the transitions of the doorways. The strips used by the maker of the laminate, typically, is made to lap over both floor surfaces. I had a laminate floor installed in my home and when it come time to add the transitions, I noticed they were only 3/4" thick, even though they were going to lap one side over my 3/4" thick oak strip floor. So I made the suggestion to the installer to rip the edge off that laps the oak floor so it flushes up to it. He would not, but he let me do it. You may be able to tell the installer to leave them off, and install them your self if you are have it done, if you are doing it yourself, well then, there you go....
I have done transitions that just consist of an extremely clean edge, with surface heights matched. In my case I was butting tile to solid-wood parquet, so the actual wood movement is very limited. Likewise, most solid hardwod floors will (unless laid very tightly, very dry) simply open and close gaps between boards (one reason narrow boards are more common - the gaps are smaller) rather than walk the whole floor a great distance. It requires a fussy standard of work - one function of typical transitions is to provide something to hide sloppy edges under.
This has not really suffered for movement space, but arguably could look better if a grout-line width of grout-color-matching silicone had been used rather than what I actually did (butt the tile up to the parquet.) A half inch would be massive overkill and visually distracting. In practice, if not bending down to take a picture of the transition itself, any appearance defects are small enough not to bother. This has been in place for 15 years or so of humid summers and dry heated winters at this point.