A few will have saw my older post on a limestone floor we are doing.

We are now having trouble with grout residue on the stone.

The limestone was fixed, cleaned, cleaned again left to dry & two coats of Lithofin Stain-Stop applied.
We then grouted, working really cleanly, but we now have grout residue on some of the limestone.

I have spent most of today washing the floor with clean water & a small light scrubbing brush to try & get into the stone. It has taken some of the residue away but you can still make out a slight haze closer to the grout lines.

Sent the site agent to CTD & he came back with HG cement & lime film remover.

Will this strip the Lithofin sealer back off the tiles?

Any help would be gratefully appreciated as we have had a nightmare laying this floor.

Hi

As you proberly no lime stone is very porus to coats of sealer proberly wasent enough

using hg cement remover wont strip the sealer off. but once used leave to dry 12 hrs then seal again that will proberly do the trick

how long did you leave the sealer i leave overnight before i grout so it can dry and harden

We tend to seal the limestone before we fix!

Originally Posted by timeless john

We tend to seal the limestone before we fix!

TJ, we didnt have a chance to get the tiles sealed before they were laid,

The house is in absolute uproar & we couldnt get them sealed without them getting covered in paint, fast set, dust & saw dust etc.

The tiles were laid & cleaned as we went (we worked really cleanly) & no one was over them, i crawled over them once adhesive was set & cleaned them twice then sealed them twice, 6hrs between coats.

Its not all the tiles that have residue on them, there looks to be 2 slightly different tiles, all from the same batch. its as though the grout residue has went into the smaller pores.

The day after i sealed the stone i tested for water ingress & the water sat in beads on top of the tile so i would say they were sealed enough.

We might just have to clean them a couple more times, its bugging me though as we went out over the hols so we had peace & quiet to get this floor spot on.

The problem with the site conditions I fully understand (got a similar 't' shirt) but unless it's a honed Limestone, I find it a product that is very absorbent and even handling the unsealed stone can cause ingress.
Once clean water has been used to prepare the tiles, it often dries at different times due to the sedimentary nature of the product and this will cause the sealer to dry at different times. The washing of the tiles before sealing can also remove some of the natural dust within the pores and allow discolouration. I've seen white limestone that was cleaned then sealed show all the streak marks from the sponges.
Good luck and keep scrubbing!

Thanks TJ,

Its wasnt looking too bad when we left site tonight, After another wash.

i may just be being over cautious about the floor as its the first limestone we have done, i dont want to seal any residue into the stone as i know that would be a worse headache than we have already.

I was surprised at the amount of dust that came out of the crate when they got delivered, cleaned the back of each tile before we buttered them.

How do you prep the tiles before fixing? ie getting rid of most of dust etc?

We set up the work benches and using a soft brush sweep the fronts.
Using a soft roller (pull not roll) the sealer across the surface in 2 directions.
Stack on edge - back to back/face to face with a spacer peg for airflow and allow to dry.
Then before fixing use a damp/dry sponge on the backs (but it must be a clean wipe).
Use either latex gloves or clean hands and hold on edges when fixing (white adhesive).

Pleased your floor is looking better.