Fixing floor grout discolouration - questions before I start

[peteuk]

Dear all,

Once again I am coming to this wonderful site with questions......

Our kitchen and utility room floor tiles were laid with light grey grout but it has stained darker in places. We assume this is grease because it won't clean off.
I have read the forum feedback but have some questions before we start to regrout the floor. I am particularly concerned to see some posts about dark grout being used which then discolours to a lighter colour. PLease can you advise?
1). should we remove the old grout by hand with a grout rake (to ensure no tile damage) or can anyone recommend a not so expensive power tool that will do the job?
2). After removal is any preparation recommended before we use the new grout? (e.g. we assume the staining is from above not, from poor preparation before the tiles were laid but just in case)
3). Are there particular makes or colours of grout that are recommended, or that should be avoided? (We are planning on a dark grout)
4). One post mentioned the possible use of a grout with "epoxy". Is this what we should look for?
5). Is a grout protector or sealant recommended and if so what make? Would this be effective or would it wear off from a floor?

Thank you,
Pete

 

[alwest197]

Did mine recently, I'm no expert though. Floor grout is very hard and I used an electric dremel with a grout remover attachment. Works well BUT you have to be very careful. I used a 6.5mm bit if I remember correctly they break very easily (about £8 each) and can run away with you and attack the tiles. I used the thin bit as I said to cut a line through the middle of the grout then used a grout rake for the rest...hard work!

I re-grouted with a dark grey colour (don't use white else you will be back where you started in a couple of months) which lightened (as it was supposed to) a couple of shades on drying.

As I say I'm no expert but it worked for me.

 

[peteuk]

Thanks Alwest97.
I am sure it's going to be hard work - the kitchen and utility are both big rooms.

Can anyone answer my other questions about material / preparation?

Cheers,

Pete

 

[tpt]

Grey floor grout is always the best bet as its undyed so it wont fade.

Sealers are worthwhile, but obviously only before staining occurs.

before you try to remove the grout completely, you can remove a fine layer using a mild acid based cleaner, this dissolves a small layer of grout. this does depend on the type of tile you have though - i'm assuming that its either ceramic or porcelain, if not tell me what it is.

Try buying some lithofin cement away and a white emulsifier pad (looks like a scourer but has no dye in it), dilute as per instructions and then use the pad to scrub it, increasing the pressure until it removes the stain. it works by dissolving a little grout.

This does work quite well and you only have about £15 to lose

 

[peteuk]

Thanks Tpt,

I'll have a go at the Lithofin idea - may save a lot of effort but I wonder if it will go deep enough.

The tiles seem to be glazed 'ceramic' or 'porcelain'. What else would they be?

Like the tip to use dark grey. I was thinking of dark brown to better match the tiles and cupboards. Will ask the boss what she thinks about dark grey as I think she'll say it doesn't go.

Thanks,
Pete

 

[tpt]

its mostly natural stone that you have to be careful with - limestone\travertine etc doesnt like acid!

just try on a small area of the tile first.

 

[tictic]

try LTP grimex first..if that doesnt work, then yes a dremmel with the correct bit for the width off your grout spacing.

 

[peteuk]

Thanks Tpt, Tictic,

Not sure when I'm going to be able to start this now (life getting in the way) but will take all the advice about trying to clean the grout first
I can honestly say I'm not looking forward to the job if it doesn't work.

Cheers,

Pete