How to Remove Concrete Grouting

I bought a house with a nice outdoor, flat stone tiled walk way.
Unfortunately the tiler/installer was "quite sloppy" in a few areas.
There many of the tiles now have a thin, but annoyingly Noticeble
coating "film" of concrete grout on the top.

I have tried coarse steel wool, with limited (slow) improvement. Is
there a better/ recommended way, to remove that concrete film? I
would really like all tiles to be fully visible, no film.

 

[Phil Hobbs]

On 1/27/19 1:32 PM, Rob_Lowe@hotmail.com wrote:

I bought a house with a nice outdoor, flat stone tiled walk way.
Unfortunately the tiler/installer was "quite sloppy" in a few areas.
There many of the tiles now have a thin, but annoyingly Noticeble
coating "film" of concrete grout on the top.

I have tried coarse steel wool, with limited (slow) improvement. Is
there a better/ recommended way, to remove that concrete film? I
would really like all tiles to be fully visible, no film.

Muriatic acid.

Cheers

Phil Hobbs

 

[Michael Black]

On Sun, 27 Jan 2019, Rob_Lowe@hotmail.com wrote:

I bought a house with a nice outdoor, flat stone tiled walk way.
Unfortunately the tiler/installer was "quite sloppy" in a few areas.
There many of the tiles now have a thin, but annoyingly Noticeble
coating "film" of concrete grout on the top.

I have tried coarse steel wool, with limited (slow) improvement. Is
there a better/ recommended way, to remove that concrete film? I
would really like all tiles to be fully visible, no film.

This newsgroup is for the repair of electronic devices.

Surely you meant to post this to the repair newsgroup, I think
alt.home.repair and just because that newsgroup has turned to mush is not
a reason to post an off topic question here.

Michael

 

On Sunday, 27 January 2019 18:33:30 UTC, Rob_...@hotmail.com wrote:

I bought a house with a nice outdoor, flat stone tiled walk way.
Unfortunately the tiler/installer was "quite sloppy" in a few areas.
There many of the tiles now have a thin, but annoyingly Noticeble
coating "film" of concrete grout on the top.

I have tried coarse steel wool, with limited (slow) improvement. Is
there a better/ recommended way, to remove that concrete film? I
would really like all tiles to be fully visible, no film.

HCl is the usual solution. It does attack some stone. Sometimes you can just wet the grout for a while then scrub it off with a plastic scourer wad.


NT

 

[Jeff Liebermann]

On Sun, 27 Jan 2019 13:32:28 -0500, Rob_Lowe@hotmail.com wrote:

I bought a house with a nice outdoor, flat stone tiled walk way.
Unfortunately the tiler/installer was "quite sloppy" in a few areas.
There many of the tiles now have a thin, but annoyingly Noticeble
coating "film" of concrete grout on the top.

I have tried coarse steel wool, with limited (slow) improvement. Is
there a better/ recommended way, to remove that concrete film? I
would really like all tiles to be fully visible, no film.

As previously mentioned, use diluted muriatic acid.
<https://www.google.com/search?q=cleaning+patio+muriatic+acid>
I did that to my parents patios and walkways many years. It worked
just fine but required some extra pre-cleaning and scrubbing to remove
some soaked in grease and dirt where I had previously rebuilt an
automobile engine. I don't recall exactly what cleaner I used except
that it was made for the purpose and supplied by the local hardware
store.

If your patio is made from flagstone, I suggest you apply a sealer
after neutralizing the acid and letting it dry:
<https://www.google.com/search?q=patio+flagstone+sealer>
After acid cleaning, the surface becomes rather porous and will absorb
and trap water, dirt, grease, mold, mildew, shoe scuff marks, etc. I
suggest you avoid the "wet look" sealer as it's difficult to keep
shiny.

This looks fairly accurate:
<https://www.wikihow.com/Acid-Wash-Concrete>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[pfjw@aol.com]

It is a process, and varies with where you live.

Muriatic Acid (follow package directions): https://www.tractorsupply.com/tsc/product/klean-strip-green-muriatic-acid-gallon-3441166?cm_mmc=Affiliates-_-Pepperjam-_-product-_-feed&utm_source=pepperjam&utm_medium=affiliate&utm_campaign=product-feed&affiliate_id=43737&click_id=2590323429&clickId=2590323429

And a stiff wire brush are your best options. Muriatic acid has a significant virtue, the active ingredient (hydrochloric acid) is volatile if not reacted, and forms salts with many compounds such that it is (relatively) environmentally benign as compared to many other options. It also attacks only the CEMENT portion of the grout, leaving the sand and stone untouched.

Other stuff:

If the walkway is subject to exposure (snow/rain) and you are in an area where there are freeze/thaw cycles, you need to be very careful in how you treat the surfaces when you are done cleaning. You may choose to seal the surface, and if you do so, be sure that it is fully dried (days, at least), and that you treat the stone and grout uniformly and with the same material. The sealant wants to be a clear, non-volatile material when cured, and absolutely not anything like Thompsons - which is absolutely worthless in any case.

https://rainguardpro.com/product/micro-seal/ is one of many Silane-based materials. Thoroseal is another. But Silane/Siloxane is the gold standard - assuming you have the gold.

So you understand the "why" of it: Most masons these days are poorly trained in how to mix mortars and grouts. Generally they make the mortar far to rich, so that it cures (NOT dries) far too hard. When that happens, water penetration into the stone pavers is greater than what it is to the grout. At which point, during the freeze-thaw cycles, the harder material (grout) will cause damage to the pavers _AND_ if that were not enough, tend to spall in thin layers. So, sealing everything properly will eliminate that problem..

In a warm climate, note that the harder of the two materials will generally fail ahead of the softer material due to thermal expansion and contraction.. First it will separate by density, then the smaller sections will start to crack.

Best of luck with it!

Peter Wieck
Melrose Park, PA

 

On Monday, 28 January 2019 14:02:40 UTC, pf...@aol.com wrote:

It is a process, and varies with where you live.

Muriatic Acid (follow package directions): https://www.tractorsupply.com/tsc/product/klean-strip-green-muriatic-acid-gallon-3441166?cm_mmc=Affiliates-_-Pepperjam-_-product-_-feed&utm_source=pepperjam&utm_medium=affiliate&utm_campaign=product-feed&affiliate_id=43737&click_id=2590323429&clickId=2590323429

And a stiff wire brush are your best options. Muriatic acid has a significant virtue, the active ingredient (hydrochloric acid) is volatile if not reacted, and forms salts with many compounds such that it is (relatively) environmentally benign as compared to many other options. It also attacks only the CEMENT portion of the grout, leaving the sand and stone untouched.

Other stuff:

If the walkway is subject to exposure (snow/rain) and you are in an area where there are freeze/thaw cycles, you need to be very careful in how you treat the surfaces when you are done cleaning. You may choose to seal the surface, and if you do so, be sure that it is fully dried (days, at least), and that you treat the stone and grout uniformly and with the same material.. The sealant wants to be a clear, non-volatile material when cured, and absolutely not anything like Thompsons - which is absolutely worthless in any case.

https://rainguardpro.com/product/micro-seal/ is one of many Silane-based materials. Thoroseal is another. But Silane/Siloxane is the gold standard - assuming you have the gold.

So you understand the "why" of it: Most masons these days are poorly trained in how to mix mortars and grouts. Generally they make the mortar far to rich, so that it cures (NOT dries) far too hard. When that happens, water penetration into the stone pavers is greater than what it is to the grout. At which point, during the freeze-thaw cycles, the harder material (grout) will cause damage to the pavers _AND_ if that were not enough, tend to spall in thin layers. So, sealing everything properly will eliminate that problem.

In a warm climate, note that the harder of the two materials will generally fail ahead of the softer material due to thermal expansion and contraction. First it will separate by density, then the smaller sections will start to crack.

Best of luck with it!

Peter Wieck
Melrose Park, PA

During normal operation, damp seeps in from the ground & evaporates from the surface. If the surface is sealed that evaporation stops, and the stone gets wetter. Try it for yourself, place 2 stones or tiles onto the earth & cover one with plastic sheet, weighing it down all round. Damp is one of those topics on which misinformation abounds.


NT

 

I am sorry, to realize I did NOT post to my desired net board!! My
oops

 

[pfjw@aol.com]

On Monday, January 28, 2019 at 12:40:45 PM UTC-5, tabb...@gmail.com wrote:

During normal operation, damp seeps in from the ground & evaporates from the surface. If the surface is sealed that evaporation stops, and the stone gets wetter. Try it for yourself, place 2 stones or tiles onto the earth & cover one with plastic sheet, weighing it down all round. Damp is one of those topics on which misinformation abounds.


NT

You do not understand how an exterior stone walk is bedded, do you? Done properly, there will be 4"- 6" of stone, 4" of sans, then the topping. Which, unless it is concrete, is seldom grouted solid. Not 'never', but seldom.

The entire 'system' moves and shifts with temperature, substrate expansion and contraction due to moisture and so forth. But, even when cut into dense clay, there is little or no need for evaporation through the top. In high moisture conditions, the entire system below the surface will remain damp and saturated. Transpiration is both too slow and to imprecise to be of concern.

What is necessary is to prevent differential freezing from the top down - that is what destroys grouted pavers. And that is why *EITHER* great care is taken to match the grout density to the paver density, *OR* the surface must be rendered impervious to moisture. If one is lucky enough to have a mason trained in the fine art of grouting, then that is the ideal.

Now, if this were to be an indoor application, then you would be absolutely correct - either a vapor barrier must be installed below the top layer (which also becomes a "paper" joint) or the top layer must be left unsealed. Note that indoor applications are seldom exposed to freeze-thaw cycles. That is why all if this suddenly becomes much more than a casual exercise.

Peter Wieck
Melrose Park, PA

 

[pfjw@aol.com]

On Monday, January 28, 2019 at 12:44:15 PM UTC-5, Rob_...@hotmail.com wrote:

I am sorry, to realize I did NOT post to my desired net board!! My
oops

You will find a multiplicity of talents herein. I have 40+ years in and around the construction industry from holding the tools to forensic analysis. Others have similar off-label experiences and skills.

Something off-topic, but also relevant to M&R can be refreshing.

Or, not to worry!

Peter Wieck
Melrose Park, PA

 

On Monday, 28 January 2019 18:37:47 UTC, pf...@aol.com wrote:

On Monday, January 28, 2019 at 12:40:45 PM UTC-5, tabby wrote:

During normal operation, damp seeps in from the ground & evaporates from the surface. If the surface is sealed that evaporation stops, and the stone gets wetter. Try it for yourself, place 2 stones or tiles onto the earth & cover one with plastic sheet, weighing it down all round. Damp is one of those topics on which misinformation abounds.


NT

You do not understand how an exterior stone walk is bedded, do you? Done properly, there will be 4"- 6" of stone, 4" of sans, then the topping. Which, unless it is concrete, is seldom grouted solid. Not 'never', but seldom.

Private stone walkways are not usually constructed that way.

The entire 'system' moves and shifts with temperature, substrate expansion and contraction due to moisture and so forth. But, even when cut into dense clay, there is little or no need for evaporation through the top. In high moisture conditions, the entire system below the surface will remain damp and saturated. Transpiration is both too slow and to imprecise to be of concern.

What is necessary is to prevent differential freezing from the top down - that is what destroys grouted pavers.

not just differential freezing, any freeze/thaw cycling when too much water is present causes spalling.

And that is why *EITHER* great care is taken to match the grout density to the paver density, *OR* the surface must be rendered impervious to moisture. If one is lucky enough to have a mason trained in the fine art of grouting, then that is the ideal.

Now, if this were to be an indoor application, then you would be absolutely correct - either a vapor barrier must be installed below the top layer (which also becomes a "paper" joint) or the top layer must be left unsealed. Note that indoor applications are seldom exposed to freeze-thaw cycles. That is why all if this suddenly becomes much more than a casual exercise.

indeed, though indoor construction is not the same as outdoor, except for a small number of historic properties


NT

 

[pfjw@aol.com]

Couple of things:

Here in the US, especially here in the Great Frozen North, if one does not bed walkways (and sidewalks) properly, their longevity is half-a-hand in years, at best. And if they are grouted, one (1) rough winter will be enough. Bed it, or lose it.

Freezing will always occur from the top down. Thawing, however, may be from either direction based on initial frost depth, nature of the soil(s) and so forth. And why all this is something of a skilled art form. Not to be done willy-nilly.

Peter Wieck
Melrose Park, PA

 

On Tuesday, 29 January 2019 13:41:13 UTC, pf...@aol.com wrote:

Couple of things:

Here in the US, especially here in the Great Frozen North, if one does not bed walkways (and sidewalks) properly, their longevity is half-a-hand in years, at best. And if they are grouted, one (1) rough winter will be enough. Bed it, or lose it.

Freezing will always occur from the top down. Thawing, however, may be from either direction based on initial frost depth, nature of the soil(s) and so forth. And why all this is something of a skilled art form. Not to be done willy-nilly.

Peter Wieck
Melrose Park, PA

Stone paths bedded direct onto soil last a very long time here. Some from over a century ago are still in service after occasional repairs. Not sure why the difference.


NT

 

[pfjw@aol.com]

Parts of the Appian Way are still level.

http://www.romeacrosseurope.com/?p=5417#sthash.8ChQejPz.dpbs

Simple enough questions:

a) Are these paths grouted (mortar between the stones)? That was what initiated the discussion.
b) How deep are the stone paths?
c) What is the size of the stones?
d) Will the climate in your area go from 50F to 4F to 35F to 58F to 24F, include 1" of rain and 2" of snow all in a 96 hour period? That is our forecast this week.

My understanding of the climate in the British Isles is, for the most part, that it is damp but pretty benign given the warming by the Gulf Stream. Sure, Scotland and some of the islands to get some extremes, but not quite the variability.

Peter Wieck
Melrose Park, PA

 

On Sunday, January 27, 2019 at 1:41:21 PM UTC-5, Phil Hobbs wrote:

On 1/27/19 1:32 PM, Rob_Lowe@hotmail.com wrote:
I bought a house with a nice outdoor, flat stone tiled walk way.
Unfortunately the tiler/installer was "quite sloppy" in a few areas.
There many of the tiles now have a thin, but annoyingly Noticeble
coating "film" of concrete grout on the top.

I have tried coarse steel wool, with limited (slow) improvement. Is
there a better/ recommended way, to remove that concrete film? I
would really like all tiles to be fully visible, no film.

Muriatic acid.

You should use muriatic acid for every 10 swimming pool cleanings, too.

 

On Monday, January 28, 2019 at 1:52:00 PM UTC-5, pf...@aol.com wrote:

On Monday, January 28, 2019 at 12:44:15 PM UTC-5, Rob_...@hotmail.com wrote:
I am sorry, to realize I did NOT post to my desired net board!! My
oops

You will find a multiplicity of talents herein. I have 40+ years in and around the construction industry from holding the tools to forensic analysis. Others have similar off-label experiences and skills.

Something off-topic, but also relevant to M&R can be refreshing.

Or, not to worry!

Agreed. My electrical construction experience is only since 1996, but you work around other contractors. The experience is enhanced.

 

On Sunday, January 27, 2019 at 11:02:20 AM UTC-8, Michael Black wrote:
> ... off topic question ...

His topic is removal of grout; so the question and replies
are on topic. The topic is out of the scope of this group
of course.

Regards, ... Peter E.

 

On Saturday, February 9, 2019 at 2:45:42 PM UTC-5, petere...@gmail.com wrote:

On Sunday, January 27, 2019 at 11:02:20 AM UTC-8, Michael Black wrote:
... off topic question ...

His topic is removal of grout; so the question and replies
are on topic. The topic is out of the scope of this group
of course.

It is on topic, because sometimes metallic and non-metallic electrical conduit runs through fill encased in concrete.

 

On Saturday, February 9, 2019 at 2:45:42 PM UTC-5, petere...@gmail.com wrote:

On Sunday, January 27, 2019 at 11:02:20 AM UTC-8, Michael Black wrote:
... off topic question ...

His topic is removal of grout; so the question and replies
are on topic. The topic is out of the scope of this group
of course.

It is on topic, because sometimes non-metallic electrical conduit runs through fill that is encased in concrete.