# buffing exposed aggregate



## sane man

We have an exposed aggregate pool deck that is rough on bare feet. I wondered if the surface is able to be "buffed" or smoothed down just enough to make it a little easier to walk on. I thought of sealing it but don't think it will really smooth down the rough surface. I was also a little worried that sealing might make it more slippery when wet. Any suggestions?


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## bkvanbek

What is causing it to be rough? Is the aggregate a smooth rock? or a rough or sharp broken rock. Exposed aggregate is usually a smooth rock.


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## sane man

I guess it's more the kids complaining that it's "bumpy" to walk on and not as smooth as the stamped concrete on the front walk, even though it's not supposed to be anyway. It looks nice, but is a bit bumpy on bare feet. I wonder if maybe a smaller stone should have been used when it was mixed with the concrete? Although the stones seem pretty small to me. It seems a lot of stone rose to the top when the surface of the concrete was brushed away, making the stones more pronounced and "bumpy". I just wondered if anyone else had tried something to smooth it out some and if there was a good technique in doing so.


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## bkvanbek

you may be able to diamond grind it, but I have never heard of grinding and polishing exposed aggregate. It should be sealed with a professional sealer with a non slip additive, like shark-grip is our favorite, it will look and feel better. Is it just in the spring that it hurts, if so maybe their feet toughen up by summer?


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## stadry

resurfacing is 1 of our work items,,, UNLESS you want to properly overlay the surface w/polymer-modified cement, your next best choice would be to diamond grind the surface,,, now knowing whether your aggregate was ' salted ' or appeared after retarder/pressure washing, those 2 are the best i can offer,,, aggregate would NOT normally float or rise ' to the top ',,, ' finish troweling ' serves to bring ' cream ' to the top,,, just rolling/spraying sealer w/' grip ' won't result in ' build ' to resolve the bumpy 'issue,,, a less-expensive 3rd alternative is to hand out sandals :thumbup:


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## stadry

to remove exposed aggregate, we use 8hp gas-power'd scarifiers then o'lay w/polymer-modified concrete to provide a level surface,,, we use eliteCrete but there are other acceptable products in the marketplace but NONE are avail in an apron/vest store :no:


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## sane man

The aggregate was exposed after the retarder/pressure washing. It almost seems too much of the concrete was removed, leaving more of the small pebbles exposed above the concrete....thus, a bumpy surface. I'm not sure sealing would build up the concrete enough to even it out with the pebbles. I was considering doing both, lightly grinding and then sealing. I'm just worried it might do more harm than good.


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## stadry

we've done this work for over 35yrs but any pro would use that method to resolve the issue,,, diamond grinding will pop out aggregate even if using an 18" diam walk-behind which typically rents for about $250 per day + diamonds,,, 7" hand grinders are less & will remove more aggregate,,, obviously looking at just 1 job doesn't give spectrum of experience necessary to diagnose the best method let alone describe the issue ( size of aggregate & avg relief )

sealers are typically 10 - 15mils thick when cured - it will take 55gal drums of sealer to reach your goal then the sealer will fail as its being asked to do something for which it is not designed,,, do what's right as previously posted & quit reinventing the wheel,,, btw, its very likely this won't be a diy project :laughing:


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## bkvanbek

I have never heard of this problem, but i don't like exposed aggregate, especially in extreme climates. If you grind the high aggregate would it create a sharp edge? Sealing should fill in between the aggregate any more than it coats the aggregate itself. But customers do say that the concrete feels better when sealed.

I would be very sure you want to do this before you start, do you have a small out of the way area to grind as a sample?


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## sane man

There is a small area that I could try grinding and sealing. I'll test it out and see what happens. Whatever I decide to do, one/both of these methods or eventually do an overlay as suggested, I'll definitely get a pro to do the job. Thanks for the advice!


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## bkvanbek

An overlay would be expensive. How old is the exposed? What condition is it in? What climate do you live in?


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## stadry

how does 1 define ' expensive ' ? is that definition opposed to OR in relation WITH value,,, are you just thinking dollars ? im-n-s-h-fo, age has nothing to do w/cost & you have adequately defined ' exposed ' at least to my satisfaction,,, climate is also irrelevant to the solution previously posted,,, be wary of advice from those who think up/deduce solutions w/o actually having done the work - good luck !:thumbsup:


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## Knoel84

*Help!*

Hi, I have been doing some major researching and came across one of your comments and it goes along with one of my problems. I just had a fiberglass pool put in, fully done through the pool company. Pools great, yards re-done. The problem...our concrete patio looks HORRIBLE! My husband chose stained exposed aggregate. They came in with one truck poured half the patio, sprayed the chemical, brushed and washed. Next truck, same thing. One side looks like regular concrete will small patches of exposed, the other looks like exposed aggregate should but feels bumpy not rough to walk on (uncomfortable). So this company came back and tried acid washing (the "bad" side) 4-5 days later and it didn't work...now we have stained (orangish pat aches on that side and stains going down the coping at the cut lines. Now they want to try and sandblast it to make it even with the other side...how is it possible to match the other side? Acid takes out the stain right? And would sandblasting even work? Shouldn't they just grind it down so both sides are even? There is also cracking in our coping from the cut lines (both sides). I have 2 boys a four year old and a 6 month old or I would have done more research beforehand! I live in Michigan too, so freeze/thaw is huge! I have so many questions,sorry, just need to get some answers! Thanks in Advance!


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## Knoel84

Hi, I have been doing some major researching and came across one of your comments and it goes along with one of my problems. I just had a fiberglass pool put in, fully done through the pool company. Pools great, yards re-done. The problem...our concrete patio looks HORRIBLE! My husband chose stained exposed aggregate. They came in with one truck poured half the patio, sprayed the chemical, brushed and washed. Next truck, same thing. One side looks like regular concrete will small patches of exposed, the other looks like exposed aggregate should but feels bumpy not rough to walk on (uncomfortable). So this company came back and tried acid washing (the "bad" side) 4-5 days later and it didn't work...now we have stained (orangish pat aches on that side and stains going down the coping at the cut lines. Now they want to try and sandblast it to make it even with the other side...how is it possible to match the other side? Acid takes out the stain right? And would sandblasting even work? Shouldn't they just grind it down so both sides are even? There is also cracking in our coping from the cut lines (both sides). I have 2 boys a four year old and a 6 month old or I would have done more research beforehand! I live in Michigan too, so freeze/thaw is huge! I have so many questions,sorry, just need to get some answers! Thanks in Advance!


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## Canarywood1

sane man said:


> There is a small area that I could try grinding and sealing. I'll test it out and see what happens. Whatever I decide to do, one/both of these methods or eventually do an overlay as suggested, I'll definitely get a pro to do the job. Thanks for the advice!


 


And if you ever do an exposed aggregate in the future, use gravel as opposed to stone for the coarse aggregate, gravel has a nice rounded surface, stone is all jagged edges and hard on the tootsies.


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## Tscarborough

Tell your kids to quit playing video games. My feet as a kid were able to walk on fire practically from summer bare foot syndrome.


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## stadry

t-scar's slightly younger'n me :laughing: here's a BIG point - ' they ' are already paid ? ? ? that's key to resolving your issue - either ' they ' man up along w/the conc plant OR you all wind up in court

far's actually getting what YOU think you wanted, either rip it all out & begin anew OR have it scabbled & an overlay installed ( we use eliteCrete BUT there are other good materials available ) [ no $ interest, btw ]

1 can't get even 2 successive conc loads the same color when you're paving a hgwy due to % moisture in sand pile, stone pile, % moisture in the silo's cement, wtr added @ plant, time in the trk, flyash, slag, etc,,, but our eyes/brain don't pick out the difference til 1 ' treats ' the conc

good luck !

ps - w/elitecrete & other polymer-modified mtls, the fine aggreate's silicon carbide, not sand, so you won't need exposed agg [ concretenetwork.com, elitecrete.com, concretelocator.com ]


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