On Tuesday, April 8, 2014 6:12:39 AM UTC-4, dadiOH wrote:
"LDT" wrote in message



The rundown: Old building, Bathroom fixtures mounted to

plywood and tile cut around their footprints (why? I have

no idea). I will be replacing fixtures, but mounting on

top of tile this time, so I'll need to fill in

discrepancies in the footprint. I have not been able to

find matching floor tile, but I do have a couple pieces

that should be sufficient for visible areas.



Someone recommended that I use quick-setting concrete to

fill in for 1/4" thick tile -under- the fixtures (not

visible). Any recommendations on brand/type of concrete?

It would be great if it set in a couple hours.



Concrete wouldn't be good, aggregate is too large. You could use mortar -

the stuff used for laying brick/block - either Type S or N. You could also

use thinset. None of those will set in a couple of hours, need about 24 to

set firm, 72 for partial cure, 30 days or full cure. Biggest advantages of

all are that they are inexpensive, readily available and easy to use.



--



dadiOH



How about this:

http://www.homedepot.com/p/Custom-Bu...6?N=5yc1vZc389

Says it sets in 4 hours and can be grouted same day. It's also $6 and the
right size for a small job.