Grounting Indian Sandstone Over Ufh - TilersForums.com

[tim441]

I will be grateful for suggestions and advice on best grout and 'how to' tips for scenario below:
1. Anhydrite liquid screed over wet UFH
2. 22mm indian sandstone installed with Granfix CSR flexi adhesive. Joints approx 10-15mm
3. sandstone is grey and used externally on patio as well with mortar joints tooled with rounded joiner tool


Plan is to seal with Geofix stone protector

Questions: Grout options?
1. Was planning to use Granfix Maxigrout - wide joint/flexible. But bit concerned whether its going to be very painful to use due to riven surface and cleaning it up etc. Any tips or suggestions how to most efficiently use a grout of this type? Want to minimise work but get good finish! Presumably using traditional sponges etc will just rip sponges and be a nightmare to clean grout from sandstone
i) best to use a grout bag?
ii) finish with rounded jointer tool?

2. Is it possible to use sand/cement mixed with flexible additive? if so what mix and type additive do you suggest?

3. any other tips and suggestions welcomed!

thanks!

 

[hmtiling]

i'm assuming you used granfix csa.
I'd go heavy on sealant first, then use bal wide joint and a washboy. i believe there are temporary sealants available to protect stone during grouting but never used one. @Lithofin BOB will be the man in know

 

[J Sid]

or just use a

and make no mess

 

[tim441]

Yes.. granfix CSA... my typo!

 

[Old Mod]

. i believe there are temporary sealants available to protect stone during grouting but never used one. @Lithofin BOB will be the man in know

 

[J Sid]

you tried it marc?

 

[Old Mod]

you tried it marc?

Yes mate, but only on quarries.
Fiddly to use on small tiles cos u need to keep it out of the joints and it takes two good coats.

 

[J Sid]

yes that would be my concern, getting it the joints.
I am looking at a floor in a listed building using old bricks cut 20mm thick next week, was considering using a protective sealer but will probably point using my gun.

 

[Old Mod]

Yeah seems to work fairly well,
In truth there's no way I kept the joints completely free of the sealer, but didn't seem to cause a problem.
Don't get me wrong I tried hard to keep the joints free of it, but, you know!

 

[Lithofin BOB]

If external grade, impregnate, as to suspend the topical. poss use the topical temp sealer above after - on a coarse grade you may need 4-6coats to fill the cappillaries - stop the grout contaminating the pores.

You could seal a spare unlaid stone at the same time, mix up a sample of grout and check and confirm grout release on a section ( ensure impregnator has cured fully)

From there you can apply coats on the sample ,one at a time of above and re test to determine the amount of coats you will require with the texture of stone you have. Then be confident you can remove on the Main floor

Or use the gun after impregnating face and edge ,and don't mess the face