Polished Concrete
- Thread starter russ_h
- Start date
If you're inquiring about polishing concrete floors, I can move this to the flooring section. It would probably get some more hits from guys that do it often.
Handyfarmer
Well-known member
there are big concrete grinders, that used diamond sections to grind the floor, and then finer and finer sections are put in and ground until the desired, finish is achieved,
I have ground off a floor or two with a floor polisher, but it is very slow and few floor polishers have enough HP, to do the job with out frying it,
the commercial grinders, are usually three phase and many times a generator is brought in to run them and normally it is not a DIY process, the cost of the grinding segments, are expensive and you need a number of grits,
when I was looking in to for a church project, they cautioned me that the floor would need some kind of hardener, such as in a kitchen, could be damaged by spills of some things. so the idea was nixed, on that project, was looking at a (potential lower cost way of finishing the floor and some thing that would not need a lot of care, sound like to keep the floor the way we would have wanted it it would have had to be sealed reasonably often),
depending on the floor finishers, one can burnish a floor with with a power trowel when pouring it, one can put a near polished finish on the concrete, use a high cement to aggregate ratio,
I have ground off a floor or two with a floor polisher, but it is very slow and few floor polishers have enough HP, to do the job with out frying it,
the commercial grinders, are usually three phase and many times a generator is brought in to run them and normally it is not a DIY process, the cost of the grinding segments, are expensive and you need a number of grits,
when I was looking in to for a church project, they cautioned me that the floor would need some kind of hardener, such as in a kitchen, could be damaged by spills of some things. so the idea was nixed, on that project, was looking at a (potential lower cost way of finishing the floor and some thing that would not need a lot of care, sound like to keep the floor the way we would have wanted it it would have had to be sealed reasonably often),
depending on the floor finishers, one can burnish a floor with with a power trowel when pouring it, one can put a near polished finish on the concrete, use a high cement to aggregate ratio,
sberry
Banned
Mine needs ground, I was going to do something different when I poured and lost access to it so it's ruff. They sweep a lot better smooth.
Handyfarmer
Well-known member
this is the type of stone I used I think I used 6 of these and a plywood disk, and a hub for a low speed floor polisher, (used a lot of water on the floor)
https://www.ebay.com/itm/Double-Str...hash=item25c087dab9:m:mvuru6pvwsYwQYDx7P3OBTw
here is some clutch plates that can be attached to a plywood disk to drive it from the floor polisher, https://www.ebay.com/sch/i.html?_od...RS1&_nkw=Buffer+Machine+Clutch+Plate&_sacat=0
one could also by 3,
4" diamond cup wheels for small grinders, and bolt them on to a plywood disk, using a 5/8" bolt.
get the, highest horse power, low speed floor polisher one can find,
use water to keep the dust down and the diamonds cool, squeegee the slurry off the slab.
one can use a metal grinder to do the edges and the corners,
I would think one could bolt a plywood disk to a power trowel as well, instead of a floor buffer, for a drive unit, I just never tried it, but at one time one could buy an abrasive brick for a power trowel (never try the brick, before diamonds were affordable, I know there were offered for my power trowel) the bricks never cut very good I know that, had one with a handle and was hand powered, they were not diamond.
this is basically what I did but used a plywood disk, and the other abrasives,
https://www.ebay.com/itm/Double-Str...hash=item25c087dab9:m:mvuru6pvwsYwQYDx7P3OBTw
here is some clutch plates that can be attached to a plywood disk to drive it from the floor polisher, https://www.ebay.com/sch/i.html?_od...RS1&_nkw=Buffer+Machine+Clutch+Plate&_sacat=0
one could also by 3,
4" diamond cup wheels for small grinders, and bolt them on to a plywood disk, using a 5/8" bolt.
get the, highest horse power, low speed floor polisher one can find,
use water to keep the dust down and the diamonds cool, squeegee the slurry off the slab.
one can use a metal grinder to do the edges and the corners,
I would think one could bolt a plywood disk to a power trowel as well, instead of a floor buffer, for a drive unit, I just never tried it, but at one time one could buy an abrasive brick for a power trowel (never try the brick, before diamonds were affordable, I know there were offered for my power trowel) the bricks never cut very good I know that, had one with a handle and was hand powered, they were not diamond.
this is basically what I did but used a plywood disk, and the other abrasives,
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ncboat
Well-known member
Just got a quote this week to grind/polish. Late cement truck and weather didn't allow the crew to stay and power trowel as planned. They jumped on it early the next morning and worked all day but it isn't as smooth as I anticipated.
Contract is to wet grind with 300 two directions then dry grind with 400, densify, dry grind with 600 and finish with 800 then seal. It includes filling the contraction cuts as well.
Cost is $4.00 sq ft.
Contract is to wet grind with 300 two directions then dry grind with 400, densify, dry grind with 600 and finish with 800 then seal. It includes filling the contraction cuts as well.
Cost is $4.00 sq ft.
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Hi, our Prep-Crete Division files tons of polishing, and we have never done or heard of doing polishing especially on a rough floor starting at a 300.
Polishing normally starts at a 40 or 80 and then goes to a 100, 200, 400, 800, with densifier at 400 and stain guard and burnishing at 800. It's important to start at lower diamonds to get the proper 'cut'.
$4.00 seems high for what they are proposing, and we question the outcome.
Have them do a mock up for you. There may be a charge which should be refundable when you pull the trigger, or if you don't go ahead with it you can make other plans.
Perhaps what they are proposing will work, but best they show you...
Polishing normally starts at a 40 or 80 and then goes to a 100, 200, 400, 800, with densifier at 400 and stain guard and burnishing at 800. It's important to start at lower diamonds to get the proper 'cut'.
$4.00 seems high for what they are proposing, and we question the outcome.
Have them do a mock up for you. There may be a charge which should be refundable when you pull the trigger, or if you don't go ahead with it you can make other plans.
Perhaps what they are proposing will work, but best they show you...
ncboat
Well-known member
Good advice, Thank you. The floor isn't rough since the concrete guys spent a full day
working on it but it isn't consistent. There are some swirl marks from the trowel as well as what I would call cosmetic irregularities. In trying to measure the price I was allowing $1.50 to $2.00 a ft for densifier and the sealer then the rest for labor.
working on it but it isn't consistent. There are some swirl marks from the trowel as well as what I would call cosmetic irregularities. In trying to measure the price I was allowing $1.50 to $2.00 a ft for densifier and the sealer then the rest for labor.
dontlifttoshift
Well-known member
In general, how much surface is removed during this process?
It depends on the surface texture that we are given...
Generally we will grind to the low areas so if the floor is a broom finish for example, we would grind down to the 'valleys'. If the floor was smooth, we may only grind off thousandths of an inch. If the client wants a 'salt/pepper' finish where we grind into the aggregate, then that could be in the 1/8-1/4" range. There really is no rule of thumb, it's very surface dependent.
Generally we will grind to the low areas so if the floor is a broom finish for example, we would grind down to the 'valleys'. If the floor was smooth, we may only grind off thousandths of an inch. If the client wants a 'salt/pepper' finish where we grind into the aggregate, then that could be in the 1/8-1/4" range. There really is no rule of thumb, it's very surface dependent.
dontlifttoshift
Well-known member
Thanks, I was just curious.
AA7483
Well-known member
I don't know about flooring but I made concrete countertops for my basement last year. The polishing was a lot of work but well worth it imo. I started with a cup grinder to expose aggregate then stepped through 50 100 and 200 with a wet polisher. Finished with 5 coats of sealer then 5 coats of wax with worked in with burninshing pads to 3000 grit.
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audioworks04
Well-known member
The process hasn’t change really over the last few years. But the chemicals have advanced a lot, specifically densifiers, sealers and hardeners. Polishing countertops is a lot of work because it is all hand work, but a floor is “easier” in that the large walk behind grinders/polishers do the work. But these polishers are very large and very heavy. The large size is necessary to keep a consistent surface finish.
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AA7483
Well-known member
Maybe I'll try floors next time!
LegacyIndustrial
ALLIANCE MEMBER
Nice work!
AA7483
Well-known member
Thanks!
ncboat
Well-known member
Guys showed to do the work and decided to start with 30 wet. They used a propane powered grinder. I didn't realize how bad the floor was unitl they started grinding. Because of the roughness we ended up with polished aggregate but it is really nice. I never intended to have a polished floor but it is really pretty. It has some color variation but for a shop floor it is overkill. I know I am going to get razed.
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Lassen Forge
Well-known member
Not from me... I love the look of polished concrete, especially if they used colored aggregate in it. Just be careful - you just created the concrete version of an ice skating rink... I'd put a superclear epoxy with some grit in it, otherwise you will hit the ground... running or not!
Radix2
Well-known member
Why do you think this? Polishing concrete does not change the coefficient of friction for concrete. Even wet it is not slippery at all. Many of the acrylic polish guards likewise do not make it any more slippery, white paint and epoxies obviously do. If you have snow on your shoes, polished concrete concrete or any smooth surface is very slippery.
I wet polished mine, and even with the slurry soup on it it was not slippery.
I think your idea of a clear epoxy may be a good idea, since I am not super happy with the polish guards at this point.
Not sure if any of the clear films would stick to a polished densified surface though.
Any comments from the vendors on a film compatable with a polished concrete surface? Wouldn't want to grind back to rough since that would destroy the clarity of the polished aggregates. Plus the acrylic has soaked into the surface to some depth.
Hi, polished concrete is generally not slippery. It is though not great at stain resistance hence why it's not used in places where heavy staining can occur, even with the use of a good stain guard.
A clear epoxy won't stick to a polished floor, it needs to be re grinded down to a # 80 for adhesion.
A clear epoxy won't stick to a polished floor, it needs to be re grinded down to a # 80 for adhesion.
Hi
First time on this site and having a problem understanding what to expect from polished concrete job. The contractor ground down the concrete, filled in 75% of the holes and large gouges, stained and finally finished with sealer. Couple of problems, seems to me he should have filled and leveled all holes, he applied the sealer in a very thick layer with cat hair and dirt imbetter and managed to get the stain and sealer all over the baseboards and bottom of doors. Is this what I should expect? I know hardwood floor refinishing and to me seems I should get similar results, smooth clean finish. What can be done to remove the sealer to get a better result.
Thanks
First time on this site and having a problem understanding what to expect from polished concrete job. The contractor ground down the concrete, filled in 75% of the holes and large gouges, stained and finally finished with sealer. Couple of problems, seems to me he should have filled and leveled all holes, he applied the sealer in a very thick layer with cat hair and dirt imbetter and managed to get the stain and sealer all over the baseboards and bottom of doors. Is this what I should expect? I know hardwood floor refinishing and to me seems I should get similar results, smooth clean finish. What can be done to remove the sealer to get a better result.
Thanks
Hi,
Your installer should have skimmed over the floor with a polishable overlay which would then be grinded and polished along with the floor so there should be no depressions if fine properly.
As for the coating you describe, polished floors don't get coated, they should have as the last step a stain blocking sealer which gets burnished in.
Floor should be re ground, skim coat applied, re polished and sealed/burnished in our opinion. Our Install Division does tons of polishing so we are very familiar with the process.
Your installer should have skimmed over the floor with a polishable overlay which would then be grinded and polished along with the floor so there should be no depressions if fine properly.
As for the coating you describe, polished floors don't get coated, they should have as the last step a stain blocking sealer which gets burnished in.
Floor should be re ground, skim coat applied, re polished and sealed/burnished in our opinion. Our Install Division does tons of polishing so we are very familiar with the process.
So is it not polished concrete that the contractor was doing. He did grind down the top layer of concrete, don't know the grit used. After grinding he used some type of epoxy to fill holes expansion joints and gouges however the filler settled and left depressions where applied. He said he used a densifier then applied a stain and finally coated with H&C Lithiun Protective Finish. The sealer shows bubbles, streaks from application, dirt in the sealer and holidays where no sealer present. Lost any confidence in this contractor, plan to withhold final payment and send on his way. Thoughts
ncboat
Well-known member
Should the floor be waxed after it is burnished and if so should this be redone on some regular time frame.
Grind off the coating. Skim over with polishable overlay like Laticrete polishable Skim coat, Refill the joints with polishable RS-88 polyurea colored joint filler, then coat with clear SPGX polyuerea/polyaspartic coating.
The depressions were from the lack of backer foam in the joints.
Alternately, give the floor a quick grind and epoxy over it with a full fleck broadcast which hides all the issues.
The depressions were from the lack of backer foam in the joints.
Alternately, give the floor a quick grind and epoxy over it with a full fleck broadcast which hides all the issues.
What are you putting on as your top layer over the heat pipes? Some of these products can be polished, but many since they are gypsum based are not. Polishable overlays are great for this but more expensive.
We have a new product called Ballistix (see previous postings or contact us directly) that can be applied over common floor levelers like Ardex, Laticrete and Schonox with almost no prep or grinding to give the look of polished concrete at 1/8 the expense and 10x the chemical and stain resistance of polished concrete.
See https://armorpoxy.com/ballistix-coatings/
We have a new product called Ballistix (see previous postings or contact us directly) that can be applied over common floor levelers like Ardex, Laticrete and Schonox with almost no prep or grinding to give the look of polished concrete at 1/8 the expense and 10x the chemical and stain resistance of polished concrete.
See https://armorpoxy.com/ballistix-coatings/
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RPH
Well-known member
When I looked into a polished floor a few years ago, it was $7.00 a square foot above the cost of the concrete work.
Went with ghostshield products and 4 different colors of acid stain. Works well for the shop.
Went with ghostshield products and 4 different colors of acid stain. Works well for the shop.
benwah
Well-known member
One thing to keep in mind, you cannot polish stamped concrete. You can either have it stamped, or make a move to polish a flat slab.
Do you want a “salt & pepper” polish, or a cream polish?
S&P is a small, random aggregate exposure. You can even go medium to large aggregate exposure but it just gets more expensive.
A cream polish honors the swirl marks left behind from the power trowel, refining and enhancing them. If the slab is broom finished, salt and pepper is your most likely option.
Concrete dyes are more popular than acid stains these days and are typically applied using a solvent such as acetone or denatured alcohol as the body carrying the dye.
Polished concrete floors are maintenance heavy. They show every spec of dust and dusty shoe print. It is necessary to sweep the common traffic areas daily to help maintain a scratch free floor. A satin or semi-gloss finish will show less wear than a 3000 grit high sheen burnish. Dust and debris acts like sandpaper when walked on.
You can probably figure around $10/SF to start, maybe more if the basement is smaller and it is a pain to get the grinders downstairs.
Hi, We have had many people the the 'polished concrete look' with full protection against virtually any liquid or chemical by using our Ballistix System. A number of posts are on GJ regarding it. Cost is very, very economical and minimal prep required. Ballistix will stick to virtually any clean, dry surface.
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dcg9381
Well-known member
I agree.. Screw all that work. Want a floor that looks great for <$2 sqft and 1/2 the work or less than epoxy? Stain it (acid/water) and polyurea... (Dunno ghostshield, I'm sure it's a great product too).
I've finished residential floors in stain/poly, they get tons of compliments. We have a big dog, not a scratch... Garage is polyurea, shop is polyurea...
Cairo94507
Well-known member
That's a lot $10 sq.ft. Maybe I will just have our floor power trowel finished? Still in the permit process so likely at least 1 year out from pour.
Hi, Ballisitix would be a great choice to get the polished concrete look but with even better protection. Generally the same rules apply for Ballistix as would for epoxy. Minimum 30 days, and do the 'moisture sheet test' to make sure the floor is not still outgassing.
See https://armorpoxy.com/checking-your-concrete-for-moisture/
Also it's best practices to do the floor last in new construction as the trades often will mess up the floor by dragging ladders and other sharp objects across it, and unfortunately there is not a 'scratch proof' floor made.
Thank you.
See https://armorpoxy.com/checking-your-concrete-for-moisture/
Also it's best practices to do the floor last in new construction as the trades often will mess up the floor by dragging ladders and other sharp objects across it, and unfortunately there is not a 'scratch proof' floor made.
Thank you.
Ballistix is not affected by any liquids, they just bead up and sit on it. Burnishing will allow absorption, Ballistix will not.
If you go the Ballistix route, we would recommend you use the non skid additive which gets mixed into the Ballistix and sprayed onto the floor along with it.
If you go the Ballistix route, we would recommend you use the non skid additive which gets mixed into the Ballistix and sprayed onto the floor along with it.
Please send quote requests to [email protected] or fill out the quote request form on the website. We do not quote on GJ due to inability for our CRM systems to track the quote. Thank you.