Do I need to use Anti Fracture Matting

[Lorenzo Antolovi]

Hi Tom. Thanks for that. I plan on using a 10mm or 12mm notched trowel for adhesive. Hopefully this will give me enough depth for adjustment. I have just measured the gap between some of the slabs that I layed out just to see them, and the gap is 20mm, erm smaller than this for there slabs just does not look that good but please correct me if this is just too wide. Also do I need a special cleaning product to clean off residual grout from the stone after grout has cured sufficiently or just old fashioned elbo grease.

 

[Lorenzo Antolovi]

Actually I think I might be limited to the width of my joint by the brand of grout that I purchased, it says 2mm to 15mm. I wonder could I get away with 20mm?

 

[widler]

You will need to seal the stone before grouting , put it on with a sponge or brush or paint pad, some seal before laying as well, but if you work clean, a bucket of clean water and sponge next to you , you should be ok, or if you’re a messy bugger , seal before laying .
Ps i like the stone , nice colour

 

[J Sid]

lay and let set and completely dry, how long? Depends on adhesive
wash and leave to dry, at least a day
seal, clean off any that doesn't soak in.
let dry, how long? Depends on sealer used
grout and clean off
wash again when grout is dry
seal again

 

[Lorenzo Antolovi]

Happy days. I'm quite clean, at least I'll try be as clean as possible. I've got 10 litres a of sealer so I'll put a coat on first anyway. 're the concrete sub floor. We have hoovered it over the years but never really washed it. How clean does it need to be before I put down a couple coats of primer. Basically do I need to get down on my hands and knees and scrub out all the doggy mess stains, food stains etc.

Also do I need anything more than the following to make any part of installation easier or better.

10/12mm notched trowel
Mixing bucket
Mixing paddle (drill mounted)
Couple sponges
Couple buckets water for cleaning
15/20mm spacers
Long spirit level

I think I will load a heavy duty bag with grout, cut hole in corner and squeeze grout into joints. Will I still need a grout float to smooth it over and do a 45 degree sweep. I think that's it, if I need anything else please let me know.

Also thank you for all the advice and info, it's really encouraging.

 

[Bill]

Personally, for that type of limestone and the joint width, I would use silver sand and cement. (save a lot of money too)

If you are not comfortable with that idea then you need to find a specific wide joint grout variety - there are plenty on the market.

Do try and work as clean as you can and you should be able to seal those after laying but before grouting. Always do a test in an inconspicuous area.

A 10mm trowel is not enough and I suggest getting a 20mm round notch like this one

20mm x 15mm U Notched Extra Deep & Extra Long Trowel £11.69 + VAT in stock - next day UK delivery plus Tile Cutters and Tiling Tools - https://www.tradetiler.com/20mm-x-15mm-u-notched-extra-deep-extra-long-trowel.html

Back butter the slabs too.

 

[Old Mod]

Agree with Tom above.
Good advice.

 

[Lorenzo Antolovi]

Cool, good advice I'll get the bigger trowel. However I have already purchased 5 x 25kg bags of Kerakoll Biofast rapid set (£26.28 per bag) and 3 x 10kg bags of Tilemaster 3000 flex grout for wide joints. If I use 20mm trowel does that mean I have to get another 5 bags of adhesive. The area is 19m2.

The second question is, the primer arrived yesterday "Kerakoll Eco A" 10 litres in total. There is allot of talk on the product about Anhydrite based substrates etc etc. I looked on their website and I can't figure out the dilution rate with water. Does anyone have any clue on this. My subfloor is bog standard concrete from a mixer wagon. Hope someone can help and thanks for previous replies.

 

[hmtiling]

Ca pietra denham stone?
Do yourself a favour and get a wide joint specific grout and 2 coats of sealant first. Universeal rapid all in one would bey choice.

 

[Bill]

just use it 2-1 for the first coat and then 1/1 for the 2nd coat for concrete.

It is a good primer.