Just finished laying my slate floor and m about to start sealing before grouting and final sealing after grouting and would like some advice on cleaning of the slate before I seal.

I have some stains of either stubborn adhesive, some adhesive residue and also a couple of grease spots and despite numerous wet washes and scrubbing, I am not happy with the marks on the floor.

Would greatly appreciate your views as I need to get the floor finished over the next couple of days before my kitchen is delivered!

Get hold of some residue remover for slate, Topps sell it, and that should clean the slate up prior to sealing and grouting.

Clean the floor with Aqua Mix Sealing & Coating remover and then Aqua Mix Phosphoric Acid that should sort it for you

Kev

An emulsifying pad and clean water will bring the adhesive marks off......as for grease spots on un-sealed slate......you might have to change those tiles......try some Lithofin Wexa ...but if you have spares it will be quicker and cheaper to replace..

Make sure it is clean and dry before you seal.....

Originally Posted by TilingLogistics

Clean the floor with Aqua Mix Sealing & Coating remover and then Aqua Mix Phosphoric Acid that should sort it for you

Kev

Careful here, Whilst phosphoric acid is mild in acid terms, Acid and natural stone don't mix and should only be applied if you know what you are doing. If the slate is honed or calibrated I'd steer clear of all acid based products, the reason being is unless you neutralize the acid after you clean it will continue to etch the stone and maybe even discoulor the grout once applied You need to use 2 handfuls of bi-carb soda in 10lt of water as a neutralizer after you apply the acid.

A far safer solution would be to try a chlorine based or alkaline cleaner first to remove any grease or addy residue.

When grouting mix up your grout stiff so you can make a ball of it in your hand and point the joints allow it to firm up before wipping down with a barely damp sponge. If you mix your grout too wet some of the fines will bleed into the edge of the slate leaving a smudge that cannot be removed. Use clean water and only grout about 1m2 at a time keeping spotlessly clean as you go. Grouting stone is tedious and hard work, just so you know.

ps Sorry Kev it was by no means questioning your advice us pros can acid clean stone but those new to stone should not.

AQUA MIX PHOSPHORIC ACID SUBSTITUTE is a premixed acidic treatment designed to remove grout haze, mineral deposits, rust stains, mortar smears, and efflorescence. Effective for the removal of most hard water stains, lime deposits, and soap scum. Also removes cement grout and mortar residue from tile, concrete, and masonry. Etches concrete. No VOCs, No phosphates.

Uses
Use on acid resistant natural stone (such as granite and slate), ceramic, porcelain, quarry, Saltillo, terra cotta,and other acid resistant tile and stone.

Coverage
Approximately 400 to 1,200 sq. ft. (35 m² to 110 m²) per gallon (3.785 L) depending on dilution.



Method of Application
READ ENTIRE LABEL BEFORE USING
1.) Read entire label before using.
2.) Allow newly grouted installations to cure a minimum of 10 days.
3.) Sweep, vacuum, or wipe surface.
4.) Pre-wet surface with water.
5.) Mix Phosphoric Acid Cleaner as follows:
LIGHT SOIL BUILD-UP: Mix 1 part cleaner to 5 parts water
MODERATE SOIL BUILD-UP: Mix 1 part cleaner to 3 parts water.
HEAVY SOIL BUILD-UP: Mix 1 part cleaner to 2 parts water.
6.) Apply solution to surface with mop or sponge.
7.) Allow to dwell 1 to 2 minutes.
8.) Agitate with a nylon or natural-bristle brush or white nylon scrub pad. Do not allow solution to dry on surface.
9.) Mop up dirty solution,
10.) Rinse thoroughly with clean water, agitating with white nylon scrub pad or brush to ensure removal of cleaning agents and acid.

Phos acid is entirely safe on slate and the sealing and coating remover will remove the grease beforehand

Kev

That's all well and good Kev, I'm sure its a great product, but natural stone aint acid resistant. It will etch.

I didn't say it could not be used It most certainly can but will need to be neutralized with bi-carb soda.

Originally Posted by MICK the Tiler

That's all well and good Kev, I'm sure its a great product, but natural stone aint acid resistant. It will etch.

I didn't say it could not be used It most certainly can but will need to be neutralized with bi-carb soda.

Mick,

I agree with you entirely and would never dream of advising any amateur to use acid on most Natural Stone however, i believe if it is used in accordance with manufacturers instructions and that includes neutralizing (See No 10 above) it is safe to use on slate or granite to remove adhesive & grout residue.

Kev