Thinset open time??

I'm trying my first floor tile job in a bathroom. I have measured and laid out the pattern for laying the tile, have made cuts in edge tiles and am ready to lay the tile.

I figured it would take me an hour and a half so I got some thinset that would set up in 4 hours. First of all, I followed instructions carefully and used the required amount of water, then added the thinset gradually while using a powered stirrer with a hand drill. By the time I got all the powder added, the mix was obviously too dry and crumbly so I added a bit more water. By now, it was getting pretty thick of course so I added a bit more water and mixed well. All in all, I probably took 20 to

30 minutes mixing. Then when I tried troweling the mix out, it seemed too dry and crumbled and formed chunks when I was trying to use the square notched trowel on it. Of course, the bucket was getting pretty warm as the mix was already setting up.

So I scraped up all the thinset before it completely hardened.

Next, I plan to use unmodified thinset. Should I really pay attention to the instructions regarding the water to add or pay more attention to the consistency of the mix. I guess it should be like creamy peanut butter, thick enough not to collapse when I use a notched trowel. For this thinset, how long will I have to work with it before it starts to set up??

Thanks for any info.

Larry T. Suddarth snipped-for-privacy@cstone.net

I just dump a bag into a mortar tub, add a quart or so of water, mix around with a trowel until water is absorbed and repeat until all thinset is wet, pretty much lumpless and at the consistency I want. ______________

More or less. I like mine wet enough so that when I form a peak with the trowel the peak slumps quite a bit.

It depends somewhat on the type and size of tile. Most of mine is Saltillo...sucks up water like a sponge. Weight should enter in too. In my case, I want the ridges left after combing to collapse some either from the weight of the tile or from applied force so that an even, thin layer is formed underneath the tile. It isn't a crises if the tile is supported only from the combed areas but the more supported the better. _____________

Never timed it. Hour? Two hours? It gradually stiffens...when it does, stir it around some more. You should have plenty of time to do a bathroom. Unless you are very slow or the bathroom very large :)

Once laid, stay off it for at least 24 hours. Longer is better.