Vitrified tiles hollow sound

[sholla]

In one room where the vitrified tiles flooring is done,
I noticed two spots where a hollow sound comes if tapped.
My neighbor said that it is possible to repair such cases by
drilling a small hole and then filling it with some glue/grout.

Does anyone has experience with this ?

Thanks
sholla

[JollyRogers]

I am not sure if it is possible to drill a small hole without damaging the tiles. I have the same issue on 1 of my tile (after replacing the previous since it had a crack), and this time I think due to the bad work I have some hollow sound coming out of it in a few places. I don't plan to get anything done as such for now. In case there is some damage etc in future, I will just replace it then.

[sholla]

This link is not very informative but shows what is possible..
https://www.youtube.com/watch?v=YmC0HUrC8rA

Also, today I talked to another tiles guy, whose solution to the problem
is to use the patti blade to open the joints on all four sides of the tile
and then pour thinned white cement slurry on all opened joints and then
tap the tiles till the slurry seeps in. I am not sure this will always work,
what if the cavity is at the center of the tile and contained all inside
the tile ?

[sateeshpnv]

My tile layer goofed up big time and created 11 such hollow tiles. He then used thinly mixed cement slurry for 3 of them, which solved the problem only for 2 of them.

I tried Roff, Laticrete and Fosroc (for power grout). No luck yet.

All solutions shown on youtube seem so simple and DIY. But, not available in India.

[tendlu]

how do you guys test this? tap on every tile or there is a better way?

also are there any precautions we can take while laying to avoid this hollow sound? i mean what to watch out for to avoid this - any relative easy monitoring technique?