How do I fill in the gaps between floor tiles?

[Jamhan]

See picture - some of my kitchen floor tiles have gaps between them, where for some reason they weren't grouted, or the grout has fallen out.
How do I go about re-filling these gaps?
Can you recommend how I would colour match without trial and error?
Do I need to do anything with the existing grout?

 

[lostinthelight]

No pictures!

 

[Jamhan]

Sorry, picture added to the original post now

 

[chris1982]

It will be difficult to match the colour of the existing old grout, I think.

 

[EddieM]

I think you have more serious issues TBH, the grout does indeed look to have fallen out, possibly/probably due to flex of the floor.

 

[Jamhan]

I think you have more serious issues TBH, the grout does indeed look to have fallen out, possibly/probably due to flex of the floor.

Do you mean serious because they will always fall out? Or serious that the floor underneath is moving significantly?

 

[EddieM]

Both.

 

[opps]

I am inclined to agree with EddieM.

You can re-grout but in time it will fall out (again).

Given that tiles have not cracked and don't seem to be loose, you could use a colour matched silicone instead of grout. It will be cheaper than replacing the tiles.

It is a bodge, but if done properly it should last for years. You will need to use a grout rake or oscillating tool to remove the old cracked grout first.

The likes of BAL and Mapei have silicone sealants that are colour matched to their grouts.

Use dilute washing up liquid when working with silicone, it stops it sticking to everything.

 

[Jamhan]

I primarily wanted to fill the gaps to stop the tiles cracking in future, assuming it was best practice.
Interesting thought about the silicone, though it does feel a bodge.
When you say I need to remove the grout, do you just mean on the currently broken/missing parts, or ALL the tiles on kitchen floor? (There are over 30, only about 8 of them have missing grout).

 

[foxhole]

Remove all grout and redo with flexible grout , if tiles are laid correctly it will soon be apparent.Though judging by pic the tiles are laid on thin hardboard .?

 

[opps]

Though judging by pic the tiles are laid on thin hardboard .?

Good spot, I missed that. Weird though, why would they have run it past the edge of the tiles?

 

[Clairenmarcus]

Can I ask the poster where the tiles are From please in desperate need as now my floor has gaps where new cupboards been fitted and they was in before we moved in