limestone resealing - Tile Advice

[radim]

been asked to reseal limestone floor about 100 m2.
not seen the job yet but guy says it has been tiled about 4 years ago, surface is waxy looking, not a clue what stuff has been used but was supplied by Porcelanosa.
what way to do this? strip sealer back to stone than reseal or just go over the top of existing sealer?
thanks for ur help.

 

[Dave]

You cant just go over the existing sealer...

If the surface is waxy looking then it could be a topical sealer or it could be a build up of cleaning product residue etc.. hard to say without actually seeing it.

I find LTP Grimex is a good cleaner for calcium carbonate based stone and it will remove the majority of topical sealers but as with ALL cleaners you test a small inconspicuous area first .

Then you need to see what finish they require , from a natural mat finish to a topical sheen finish ... i prefer a natural finish as it lasts longer than a topical finish IMO.

And if i can i use a water based sealer , it kinder on the environment and doesn't stink the customers house out and i find they do not darken the stone appearance like some solvent based sealers do.

 

[Lithofin BOB]

As David , I would remove existing finish completely using a stripping agent- we have lithofin wax off .this will ensure full removal of existing finish ,as not to compromise new impregnator.

I dry my floors 5-7 days minimum to release all moisture from the clean/ strip,and after (as above)use your impreg/ finish dependant on how client wants to look.

 

[trustiling]

You wouldn't need so long to dry the floor if it had been down for some time and the underfloor heating was on though, surely you could seal more prompt while the floor is still clean and less chance if being stained while unprotected?

 

[Dave]

You wouldn't need so long to dry the floor if it had been down for some time and the underfloor heating was on though, surely you could seal more prompt while the floor is still clean and less chance if being stained while unprotected?

Just to add , you can seal earlier with a water based sealer than if using a solvent based sealer... as long as the stone isn't wet ... but slight damp is ok.. well it is with Fila w68 anyway.... not sure on lithofin's water based as yet to try it.. hence another thread i asked on.

 

[Lithofin BOB]

I mentioned the 5-7 days or until fully dry as these are my personal dry times for my restoration co, yes they will differ dependant on density and porosity of stone but also porous cement based grout which also need to dry fully. generally floors will be fine left fore this times as client is aware to be careful. i would also not recommend drying floors with underfloor heating as this can bring on salt formation and discolouration in some stones.

As far as the sealing damp floors issue, no , i would not recommend sealing a damp stone with water based- yes, you will get away with it (no application marks as you would from a solvent based), but the performance of the repelling action from the product will be less than if the stone was fully dry. the w68 does state that the floor can be impregnated if damp, but then states that the floor should be clean and dry!! on the application Tech instructions.

i would always recommend that the stone be dry using any water based (Eco or W )or solvent impreg (MN) for the best results and longevity of the product.

 

[aytiling]

I use Butchers Bare knuckles to strip off everything, even gets over application of Linseed oil off, magic stuff

 

[Lithofin BOB]

I use Butchers Bare knuckles to strip off everything, even gets over application of Linseed oil off, magic stuff

Hi AY -This is caustic soda- sodium hydroxide ,you would need to be causiouse with this product on a lime stone As can cause formation of salts or poss ferric hydroxide -rust staining in some stones.
fine ( after testing) on your clays /terracotta,

 

[aytiling]

Hi AY -This is caustic soda- sodium hydroxide ,you would need to be causiouse with this product on a lime stone As can cause formation of salts or poss ferric hydroxide -rust staining in some stones.
fine ( after testing) on your clays /terracotta,

I know it is, that's the beauty of the stuff. As long as it's diluted properly and washed off immediately it's the dogs.
You can keep your Wexa's and suchlike, I want something that works every time, and this is the baby.
I know what it does on Limestone, I've been using it for 20 years or there abouts.

 

[Lithofin BOB]

Was more of a cautionary to others, as have had many floors destroyed with this type of product in the wrong hands. Have used it my self for 25 ,as you know it's all about the testing.

Not on here for pushing wexa

 

[jonnyc]

crickey, that takes me back.
butchers bare knuckles
I used to use this quite often for stripping floors over sealed with boiled linseed oil.
must be going back over 20 years
it was indeed great at that job but never tested it on limestone or other scenarios