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drillbit 12-10-2008 12:27 AM

Polished Concrete Question(s)
I am going to attempt to polish an existing concrete slab.

I have the tool and the appropriate pads.

What I cannot find is a penetrating sealer (densifier) to apply during the polishing process. Well, unless I want to spend hundreds of dollars and have way more then I need. I only see these products sold in 5 gallon containers.

I don't want to stain the slab. I just want it to be naturally polished and protected.

I really don't want to do all this work and paint something on top of it, as in sit on top sealers or (yikes) epoxy. I would prefer to have a penetrating sealer/densifier and then polish it to a shine.

My question is. Is there a product available that can accompolish this and available in a gallon size?

If not would it be completely silly to use a penetrating sealer for grout on the slab?


drizzle 12-10-2008 07:50 AM

Penetrating clear sealer
You can get a penetrating clear sealer at They sell it by the quart, gallon and 5-gallon bucket. A gallon is about $35.00. Good luck with your project!

Bud Cline 12-10-2008 05:54 PM

You may want to do more research.:)

yesitsconcrete 12-11-2008 08:41 AM

just wondering if drizzle's shilling or recommending based on h/o-dif experience,,, google what you need.

drillbit 12-14-2008 10:51 PM

Thank you everyone for the replies.

I have researched this for a while now.

For my plans I think I need to apply a penetrating sealer/densifier then some sort of penetrating waterproofer. Inside and out. The slab is both interior and exterior so there is currently a few spots that draw moisture inward via the slab.

Nothing is easy.

As it stands I can spend 200 dollars on enough sealant material to solve the issue or for 150 more have way too much. So I am feeling out others who might want to go in on the cost.

The grout sealer idea is indeed silly and I was just blown away by the cost.

All the while I await my wet polisher and diamond pads.

My question for the experienced would be...

At what grit in polishing do you apply the penetrating sealer? Do you continue to polish afterward?

Final waterproofing penetrating sealer? Same question.

I am inclined to thing they are both applied after all polishing. Yet you might want to have a more porous slab to receive the product?

Apparently concrete is an art and a craft.

Many thanks.

yesitsconcrete 12-15-2008 05:31 AM

' have the tool & appropriate pads ' was how this started but now you await - which is it ? ? ? no, its not just art & craft - its also talent, experience, educated guessin', & continual learning thru trial & error,,, while every slab's different in design mix, was placed differently, & cured differently, there are some common denominators but nothing specific,,, its still ALL ' guess & by golly ! '

btw, you never mention'd how many sf you're attempting to polish; 2, can't imagine this ' polisher ' you now await's anything a pro'd use; or 3, wet or dry; or 4, there're other ways to get the result you want/think you want w/o such a capitol investment.

not only does it take 100's of $ for mtls but 10,000's $ in equipment,,, that's the easy part,,, never did understand the ' penetrating sealer for grout ' UNLESS you meant a product used for tile grout,,, they won't work - our densifiers're much different,,, would think all your research's been fruitful so why the questions now ? ? ? btw, polishing IS waterproofing & a densifier makes conc harder,,, if there's moisture, the best guess's its coming from under the slab however you may want to research that, too.

we'll usually try 400 - 600 for the densifier but it doesn't always work - some guys apply towards 800 while others don't - no set answers, bud - its ALL learned on the job, not by reading labels, visiting websites, posting in forums, or reading books ( of which, to my knowledge, there are none ! ),,, so far, this trade's unregulated, unspecified, &, yet, overpopulated w/those who don't know their *** from a hole in the ground - so what's new ? ? ? :laughing:

whether its 110 house voltage or 440 3-phase, wet or dry, every job's different,,, we never even got into the $6k wet/dry vacs, did we ? ? ? if it were easy, everyone'd be doing it :thumbup: profit's the motive &, from the pricing i see in the mktplace, no one's making a killing.

' Apparently concrete is an art and a craft. ' ,,,indeed & this is becoming clearer just NOW ? ? ?

drillbit 12-18-2008 09:34 PM


Originally Posted by yesitsconcrete (Post 198180)
unregulated, unspecified, &, yet, overpopulated w/those who don't know their *** from a hole in the ground ? ? ? :laughing:

:thumbup: Whoo who. That's me.

Thanks for your post. It is frustrating to attempt a task that you don't know much about, but want to learn. I agree that it is a talent acquired by experience, that is what I meant by the terms "art and craft".

Yet, I have to start somewhere, right?

This is a personal home improvement and in my area there are no "polishers". There are dudes who will come and overlay (I don't want that).

So, I purchased and received yesterday a wet/dry polisher. It is hand held (D handle) and came with diamond resin pads, 50-3000 in grit. It has a gfi. I have about 300 sq/feet to do. My slab is pretty smooth (broom finish). I was told the pads should last for 600 sq feet. I hope so.

Yes, it will suck and take forever. However, I willing to try.

I spent a month sanding another (wooden floor with a combination of hand held sanders). So I am persistant.

I'm pretty sure my moisture is due to the connectivity of the slab to the outdoors and in. Rainwater can slightly pool outside in an area and of course it would permeate the slab and disperse indoors. Although I have only noticed the problem in 2 small areas. So maybe there is a slight leak?
I will have to figure something out about that.

Thanks for your help.

drillbit 02-16-2009 10:19 PM

Still sanding. All of it with a 4 inch grinder.

In hindsight I should have perhaps used one of those scary looking metal cup wheels first. How mean are those?

My floor has gone from a rough broom finish to be able to be sponged moped.

I'm still waying different penetrating sealers and hoping the finer grits will sand faster and last longer.

My moisture problem is in one and/or possibly 2 areas outside of the room. The seam that is flexable grouted on the inside but not outside and a low spot in the concrete that puddles right at the exterior wall.

I will fix both when the weather warms and hope that takes care of the wicking moisture.

The floor looks real nice when freshly mopped. Dark gray. Is there a penetrating sealer that can enhance this and offer protection without being topical?

drillbit 05-25-2009 09:44 PM


This sucks.

I have grinded and honed and grinded and honed somemore.

After experimenting with different pads I found some actually do last a while. They are velcro floor pads that are very thick. Advertised to last over 10k square feet. They don't even last a mere 200 square feet, but are better then the thin 2mm ones. IMHO.

They also only come in 3 inch diameter which reduces my coverage even more. They are meant to be 3 pads to a floor grinder, but I don't have that just a hand grinder.

This is a side project and after being crouched on the floor for extended hours, I find other things to do.

I used a penetrating sealer after a second pass of 100 grit. I was concerned about using the right sealer, but cost and the amount I would need made me not care so much so I went to the big box store and purchased a kwikcrete natural penetrating silicone sealer.

4 gallons later I was glad I went cheaper.

I'm now ground to 800 grit and the floor is starting to darken in areas, but I do have lighter areas that I may have to go back a grit or two to get the look and depth I want.

I did think that the higher grit pads would last longer, but that is not the case.

I've tried to pop the shine in a few corners by going through the 1500 and even 3000 grits to see what will happen. I'm just not seeing powerful shine. Although there are tiny signs of hope.

Honestly if the floor is smooth, able to be moped and water and stain resistant then I will live with it. That is what I have now, but I may sand some more to get a confusion of darkness thing going.

The cool thing is that water moves around the floor like mercury it is so sealed. That is kind of groovy.

Anyway, after this I'm sure I could polish to shine a counter that I formed myself. Considering most of my grinding was removing a ridged broom finish.

While this project is months going. I probably only have a couple of weeks invested. It is very hard work and my hope is that the result will be worth it.

Thanks to everone for their help and when (and if) I ever finish I will post a picture.

drillbit 06-07-2009 10:05 PM

1 Attachment(s)


I have been working so hard. An entire floor with a tiny 3 inch pad.

I grinded it to 1500 and this is the result.

Left side is the 1500 grind mopped and dried. Right side ground to 100 grit and mopped and dry.

Attachment 11061

Sure that is a great difference. However the shine is honed at best and upon grits of 800 and above a brown color seem to embed itself into the concrete.

I thought this would mop off, but it's in there. The resin from the higher grit pads had this tan color so my theory is that some of this resin was embedded in the concrete. It comes right out if I go back to 200 grit. However the little sheen I did achieve is also lost. Grrr, here is an idea, make the pads gray resin?

So I think I might be better off just grinding it all to 200 and using a topical sealer. Although it is not "real" polished concrete. It might be the best result I can achieve.

I'm so bummed.

drillbit 06-09-2009 04:43 PM

Hello silicone carbide sandpaper.

Regressing back a few grits I am able to get most of that brown out of the slab. Cool.

The floor is so smooth that the sandpaper does last a fair bit. Of course it is super cheap compared to those resin pads so I think this might be what I finish the shine with.

I'm actually at a smoothness level that painting a topical sealer not only feels like giving up. I also don't think it would adhere well.

Running a sander on the floor feels like driving a Lincoln Town car after those tiny resin pads. I may have to change paper every 5 minutes but overall at the upper grit level, it is much faster.

I think the shine may improve as well.

I hope this plan works.

The little sander that could. I think I can....I think I can...I think I can.

drillbit 06-12-2009 11:44 PM


The sandpaper works and was actually faster. It took me 2 days with a palm sander to rid myself of 5 days work with the resin pads.

I have half the floor polished to 1500.

The brown resin stains are gone and the floor is a nice soft gray with a better reflectivity. You can see window outlines and light reflections.

I have to order the finer grits to get me to 3000 on line. After seeing the difference between 800-1500. I definately think it will be worth it to try to go for it.

There sure are alot of views. My guess is that half expect me to fail, half want to read so they can learn by my experience, and a majority think I'm crazy.

I'll try to get some more pictures up soon.

Knucklez 06-13-2009 10:22 PM

4 Attachment(s)
just keep in mind that the smoother you go the less your sealer will be able to bite & hold to the floor. if you go higher than 1500 grit, you'll have to spend some attention to the type of sealer you chose and make sure it can stick well for so smooth a floor.

i just polished some concrete to 1500 grit. its smooth as glass. then i applied some acrylic penetrating sealer. you have to put that stuff on in mass quantity and then wipe away the excess. if you do a little bit at a time, it dries quickly and leaves streaks.

good luck, and post some pic!


drillbit 06-14-2009 10:28 AM

2 Attachment(s)
Thanks Knucklez,

I did apply a penetrating sealer to the entire floor after I ground it to 100 grit. I used a pump sprayer and after a few minutes of applying and soaking in and reapplying I wiped up the excess with rags.

It is still relatively well sealed however, I may apply a second application after I get the entire floor to 1500. Just to make sure the entire floor is as sealed as possible. Or would that be bad???

Here are some pictures so far.

Attachment 11177

This is 1500 grit on my floor. You can start to see the panes of the french door above. All that icky brown came out after I went back a few grits and used silicon carbide sandpaper. The floor is a nice cool gray and that looks good against all the exposed brick and concrete that already exists in the room.

Attachment 11178

This is a close up of the area I took a picture of in the above post about the brown resin burning itself into the surface. The brown is gone.

You can really see the difference in 1500 grit to the left and the 100 grit area to the right.

Your counters are looking awesome by the way.

I'm beginning to flirt with the idea of wood counters instead. Mostly because I'm a little over concrete at the moment and wood might be a nice contrast to a room that has so much brick and concrete already in it?
Also because wood is a heck of alot easier to sand and work with in general.

Knucklez 06-15-2009 11:11 AM

4 Attachment(s)
looks like your floor has some voids in the surface? those can be filled if you don't like them.

i don't see any problem with putting more sealer on later. i waited 24 hours between applications, as recommended.

for extra polish you can rent a drum sander with a buffing pad and put down some special for concrete wax.

there was a time when i was considering a butcher block countertop. that is something you can make yourself, but you must do some research so that you can get the right type of wood for this. also, look around local woodshops and mills and phone and ask how wide their planers are. there is someone in town where i live that can plane 24" wide which is pretty impressive. you'll need to do that after you biscuit and glue your wood countertop together. then it is perfectly level and ready for sanding .. lots of sanding.

thx for the countertop comments. i'm a little sick of concrete myself.

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