What is your grouting technique for very riven slate ?

[qualitywork]

Hello guys, I have a 40 metre slate floor to lay in opus next week.
The slate is highly riven and will grout in silver grey.
The slate will be washed and then sealed with Matt stone sealer.
Will lay around the heating mat with an s2 adhesive, s1 elsewhere.
I have 2 questions ;
What grout would you recommend for ease of grouting ?
(There will be a 9 meter heating Matt and I have laid insulation boards ready for it.)
How would you grout the floor ?
I normally just use a washboy and keep changing the water, but these are very riven and I’m scared to death of leaving grout residue in the crevices.
I posted a thread on this issue about 8 years ago on here.
That job was a nightmare as I worked 3 days for nothing, cleaning up.
I don’t want to repeat the same mistake !
Any tips or techniques / advice would be much appreciated.
I’m looking for a fail safe solution.
What works for you ?
Best regards
James

 

[Old Mod]

Tile protector

You could look into this, but make sure it won’t react with your sealer first.

Maybe uncle Bob could give you options.
@Lithofin BOB

 

[qualitywork]

Thanks 3_fall, I will contact bal regarding this. Just don’t want to make any mistakes on this.
Anybody else got any advice ?
I do a lot of Natural Stone work these days, but these tiles are so riven.
I also mindful of washing out the colorant in the grout by going over it to many times. Don’t want the colour to be patchy.

 

[One Day]

Throw the washboy and get some gloves on for this one! I would seal it to saturation (I use Universeal / Lithofin) and very very methodically clean and wash a small area at a time, rinsing sponges very well each time.
Never put the sponge across the same area twice and pay particular attention to the nooks and crannys.

It's not an easy task but definitely can be ruined by rushing.

BAL temporary sealer isn't any use in my opinion IF all is sealed properly before hand.

 

[On one]

As Above......seal,seal and seal again.
Many years ago I did use Bal Temporary sealer (unsuccessfully) but that was on a riven porcelain floor

 

[Lithofin BOB]

I would recommend testing the grout release.take a couple of tiles- bad riven ones, impregnate them with your chosen Impregnator. Leave to cure, minimum 12 hrs on a solvent- this will give the maximum reppelance , mix up a small amount of grout and work over the tile. Once dry, if there is contamination , you may want to use a temp sealer or other product to ensure the full grout release. Impregnators only line the capillaries ,they do not fill them.
I would do a test on your other impregnated tile adding the topical sealer- when I test this, I will take a 600x 300 slate- split it into 1,2,3 and 4 coat sections then let it cure and grout over it. This can then determine amount of coats required, as the stated coats can somtimes not be enough or wash off to quickly and still contaminate the tile. If there is a slight residue of sealer when washed off, this can be easier to clean off than a grout residue from within the surface pore.

I Test this with all stone,tiles,crackle glazed and cement Encaustics, just because it's sealed/impregnated ,this does not mean that the grout cannot get caught in the surface.

How long do you leave the slate after washing, before impregnating it? This will make a huge difference in the reppelance of the product you use.

 

[Flintstone]

Good advice here already, you could try using a pointing gun or grout bag if you want it to really be a clean up, more time consuming to apply but less time washing

 

[qualitywork]

I would recommend testing the grout release.take a couple of tiles- bad riven ones, impregnate them with your chosen Impregnator. Leave to cure, minimum 12 hrs on a solvent- this will give the maximum reppelance , mix up a small amount of grout and work over the tile. Once dry, if there is contamination , you may want to use a temp sealer or other product to ensure the full grout release. Impregnators only line the capillaries ,they do not fill them.
I would do a test on your other impregnated tile adding the topical sealer- when I test this, I will take a 600x 300 slate- split it into 1,2,3 and 4 coat sections then let it cure and grout over it. This can then determine amount of coats required, as the stated coats can somtimes not be enough or wash off to quickly and still contaminate the tile. If there is a slight residue of sealer when washed off, this can be easier to clean off than a grout residue from within the surface pore.

I Test this with all stone,tiles,crackle glazed and cement Encaustics, just because it's sealed/impregnated ,this does not mean that the grout cannot get caught in the surface.

How long do you leave the slate after washing, before impregnating it? This will make a huge difference in the reppelance of the product you use.

Throw the washboy and get some gloves on for this one! I would seal it to saturation (I use Universeal / Lithofin) and very very methodically clean and wash a small area at a time, rinsing sponges very well each time.
Never put the sponge across the same area twice and pay particular attention to the nooks and crannys.

It's not an easy task but definitely can be ruined by rushing.

BAL temporary sealer isn't any use in my opinion IF all is sealed properly before hand.

Good advice here already, you could try using a pointing gun or grout bag if you want it to really be a clean up, more time consuming to apply but less time washing

Thanks so much for the replies. Really helpful info !
I will make sure i seal them twice before they go down.
The customer has supplied ltp mattstone.
Do you think that is ok for what i am doing ?

 

[Qwerty]

Thanks so much for the replies. Really helpful info !
I will make sure i seal them twice before they go down.
The customer has supplied ltp mattstone.
Do you think that is ok for what i am doing ?

Yes. Mattstone is a good sealer for slate

 

[qualitywork]

Yes. Mattstone is a good sealer for slate

Thanks Plan Tec. I have always used Mattstone in the past. I have probably laid about 50 slate floors before and only ever had one problem, which as I mentioned earlier in my op, was about cleaning down the grout.
These tiles are the most riven that I will have laid so I am very cautious.
I read in the past that somebody on here recommended about putting some grout residue remover in the washboy bucket. Does that help with cleanup ?
Also I haven’t bought the grout yet.
What would people recommend ?

 

[Lithofin BOB]

Pre- sealing the stone prior to laying- ? Would check that with the manufacturer of the Impregnator.
Residue remover in the wash water.
Is your slate acid resistant- not all are.
Acidic based products can have an effect on the grout- whitening a curing polymer binder or discolouration at its curing stage, generally recommend that any grout would be dry and fully cured before washing or cleaning.

 

[qualitywork]

Pre- sealing the stone prior to laying- ? Would check that with the manufacturer of the Impregnator.
Residue remover in the wash water.
Is your slate acid resistant- not all are.
Acidic based products can have an effect on the grout- whitening a curing polymer binder or discolouration at its curing stage, generally recommend that any grout would be dry and fully cured before washing or cleaning.

Sorry, my mistake. Sealing twice after laid and before grouting.
I think i am just gonna go very slow and be methodical.
Lots of water changes and wipe downs.
Thanks for all the advice.
Appreciated !
James

 

[Time's Ran Out]

Riven slate - best grout - sand and cement!

 

[Dumbo]

Brush it in and spray with water

 

[Flintstone]

Riven slate - best grout - sand and cement!

I agree, not flexible tho for timber floors!