I am setting 12 X12 glazed ceramic tile on my basement's concrete
floor. I have been using premixed mortar from a big box store,
applied with a notched trowel the way you're supposed to. I have a
few questions, all stemming from the fact that the mortar is not
setting up as fast as I thought it would. The mortar on tiles I set a
week ago is still soft!

1. The basement is damp, but not wet - is this normal? Will it
harden eventually? Is there something I can/should do to speed it
up? When I say damp, I mean the floor generally appears dry, with
maybe a little visible dampness or seepage in the corners after a
heavy rain. Mortar that is in a very thin layer - like where I wiped
up along the edge where I stopped working, leaving a very thin layer -
that dries out and sets fine.

2. Do I have to wait for the mortar to harden before grouting?

3. Would it be different if I used the dry stuff instead of the
premix? I was thinking of switching to the dry mix anyway to save
money.

thanks in advance, -- H

On Aug 9, 12:29*pm, Heathcliff wrote:
I am setting 12 X12 glazed ceramic tile on my basement's concrete
floor. *I have been using premixed mortar from a big box store,
applied with a notched trowel the way you're supposed to. *I have a
few questions, all stemming from the fact that the mortar is not
setting up as fast as I thought it would. *The mortar on tiles I set a
week ago is still soft!

Get it off the floor before it cures!
-----

- gpsman

On Aug 9, 5:29*pm, Heathcliff wrote:
I am setting 12 X12 glazed ceramic tile on my basement's concrete
floor. *I have been using premixed mortar from a big box store,
applied with a notched trowel the way you're supposed to. *I have a
few questions, all stemming from the fact that the mortar is not
setting up as fast as I thought it would. *The mortar on tiles I set a
week ago is still soft!

1. *The basement is damp, but not wet - is this normal? *Will it
harden eventually? *Is there something I can/should do to speed it
up? *When I say damp, I mean the floor generally appears dry, with
maybe a little visible dampness or seepage in the corners after a
heavy rain. *Mortar that is in a very thin layer - like where I wiped
up along the edge where I stopped working, leaving a very thin layer -
that dries out and sets fine.

2. *Do I have to wait for the mortar to harden before grouting?

3. *Would it be different if I used the dry stuff instead of the
premix? *I was thinking of switching to the dry mix anyway to save
money.

thanks in advance, *-- H

Mortar Is a mixture of sand and cement so any pre-mixed stuff is
obviously not mortar. It would be hard:-)
If you have the normal cheapy glazed tiles you can use the pre-mixed
stuff. It hardens as water is drawn out of the mixture by the the
tile and the substrate.

The reason your tile adhesive is not hardening is te substate s
obviously damp and you have impervious-to- water tiles so it's not
going to go off any time soon because no water will be drawn out.
.. What you need is a cement based adhesive that will come as a dry
powder & you add water to it when you use it. This hardens
regardless. There are ones made expressly for ceramic tiles. This is
a known problem.