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Craig Zettle
09-13-2005, 7:15 PM
I was laying about 17 bags of cement in between 2 houses (not enough room for a mixer, decided to do it by hand), and used the commercial grade Sakreet. You have to understand this is not my thing.
Well, to make a long painful story a short painful one, I ran a broom over it too soon and brought up the stones in the mix. The surface goes from kind of rough to really rough. I am a perfectionist and am ready to start drinking professionally.
Is there anything I might be able to do to it to smooth it out a bit? I know I could just bust it up and start again, but the cement actually took quite well(read: hard as heck)

Craig

Don Baer
09-13-2005, 7:25 PM
Craig,
I feel for ya man. You needed to wait a lot longer before brooming it but I guess you figured that out. I did my share of cemets work and don't envey you. The only real solution I can think of is to bust it up and start over. some might try a slurry coat but I've never been succesful at doing that.
Last summer when I replaced the side walk at my mothers house we rented an electric jack hammer for about $50 from a local rental yard then when we took it back we picked up a half a yard of cemet in a minature cent trailer that resembled a small version of the back of a cement truck. I figure you need about .43 CU Yards to do the job if you were using 90 lb bags.
Good luck, maybe someone else can come up with a better idea.

Vaughn McMillan
09-13-2005, 8:12 PM
Craig, depending on the roughness of the slab (and the desired smoothness), you might be able to smooth things up with a concrete rubbing stone. I've attached a picture, but it's essentially a piece of very coarse carborundum with a handle attached, similar to a rubber concrete float. It'd involve a lot of work, but it might be easier that tearing ot out and starting over again.

Another possibility might be to use a very stiff wire brush (and perhaps some acid) to remove more of the cement paste, ending up with an "exposed aggregate" finish. However, if the aggregate in your concrete mix has fractured faces (instead of smooth, rounded rocks), the exposed aggregate idea might not be workable for you. (As an aside, my dad helped pioneer cast-in-place exposed aggregate concrete back in about 1957 at the Air Force Academy in Colorado Springs. They did thousands of cubic yards of the stuff for the parage grounds. It was the first time exposed agg slabs had been done outside of a prefab factory.)

As Don mentioned, a slurry coat is problematic, especially if it's exposed to freeze/thaw cycles. If you have the leeway elevation-wise, you might be able to pour another concrete slab (2" to 3" thick, the thicker the better) on top of your messed-up one. You would need to use a bonding agent to get the two slabs to stick together. By using a full concrete mix (as opposed to a cement paste slurry), you avoid many of the problems slurry presents. Still not a walk in the park, but probably easier than tearing it out and starting all over again.

I hope this helps -

- Vaughn

Craig Zettle
09-13-2005, 10:00 PM
Thanks for the replys guys.

Vaughn, where can I get a concrete rubbing stone? Never saw one, but I would like to try it.

Don Baer
09-13-2005, 11:11 PM
Craig,
While I was finishing my diner and enjoying some fresh cucumber and tomatoes from the garden I was putting some salt on the vegies and had a though for you. If you do have to redo the cement you might consider rocksalt rather then brushing. My pool deck and walk along the side of my house are done that way and it works well as well as looks good , it's easy to do and save a lot of time. After gnd fiishing the cement while it's still wet just throw a bunch of rock salt on the wet cement. You guys who live in the snow belt should have no trouble getting a bag of this stuff. Just thow it all over the wet cement and come back the next day and hose it off.

Norman Hitt
09-13-2005, 11:15 PM
Thanks for the replys guys.

Vaughn, where can I get a concrete rubbing stone? Never saw one, but I would like to try it.

Craig, almost anyplace they sell sakrete should have them. They stock them at the HD's around here. You have NO IDEA how much work this will be, but keep it wetted down and the sooner you get on it the better, because it will only get harder the longer it cures.

One other "Possibility" you might try; Send a PM to Mark Singer, and see if he thinks you could put a thin layer of "ARDEX" Self Leveling Concrete Topping over it, and he would probably know if it would work in this application, as he has recommended it for some applications before, here on the forum. (If it would work, it would certainly be a LOT LESS hard work).

You can read about it at: http://www.ardex.com/prod-sdt1-bro.htm

Bill Lewis
09-14-2005, 6:55 AM
While I'm not a concrete worker, I have done my share of mixing and poring of the stuff. The only thing I can say about Sakrete is that it is good for footings and not for finishing. Sakrete just seems to me to have too high of an aggregate content for finishing. If you need a better finish adding some portland cement to it seems to help. I know this doesn't help your current situation, but maybe it'll help someone else in the future.

Steve Jenkins
09-14-2005, 8:20 AM
So that's the name of that thing."Concrete rubbing stone".

I spent many days over one when i was a kid. Dad called it a holy-stone. the reason is obvious afeter you use one for a minute or two.

The position is on your knees with both hands on the stone. Leaning on your hands push the stone away thus lowering your head to the floor then pull it back. Repeat adinfinitum. :)

The ones I wore out didn't have handles just a big block of carborundum.

AAAHHH the memories :rolleyes:

Stuart Johnson
09-14-2005, 9:02 AM
On one of the home improvement shows (probably TOH) they miss poured in the basement. They used a machine similar to a floor buffer to grind it down. I have no idea where but you might be able to rent something similar.

Vaughn McMillan
09-14-2005, 5:13 PM
Craig,
While I was finishing my diner and enjoying some fresh cucumber and tomatoes from the garden I was putting some salt on the vegies and had a though for you. If you do have to redo the cement you might consider rocksalt rather then brushing. My pool deck and walk along the side of my house are done that way and it works well as well as looks good , it's easy to do and save a lot of time. After gnd fiishing the cement while it's still wet just throw a bunch of rock salt on the wet cement. You guys who live in the snow belt should have no trouble getting a bag of this stuff. Just thow it all over the wet cement and come back the next day and hose it off.
Don, he does not want to do this in a snowbelt area of the country. It looks great here in California, but subjected to one or two seasons of freeze/thaw cycle, a rock salt finish will spall (surface flaking off the slab) like nobody's business.

Even though I was raised by a concrete engineer, I never saw a rock salt finish on concrete until I moved to CA. It's great around a pool, and it looks very nice, but it'd never hold up in cold country.

- Vaughn

Don Baer
09-14-2005, 5:29 PM
Thanks Vaughn, I never had to shovel snow so I guess I live and learn...:D

Vaughn McMillan
09-14-2005, 6:08 PM
Don, when I have friends or relatives visit from snow country, they often comment about the steep streets and driveways they see around SoCal, and how they'd never see slopes like that back home, because they'd be impassable for part of the year. It took me a few years of living out here to get used to no snow. (Putting up Christmas lights in shorts and a t-shirt, or roses blooming on New Years, or mowing the lawn in February.) ;)

- Vaughn

Michael Ballent
09-14-2005, 6:36 PM
Isn't there a power tool equivilant for that tool? There have been some concrete work going on at my workplace, and I saw some guys using something that looked like angle grinder and some cone shaped thing on the surface of the concrete... It threw out a ton of dust... Perhaps is rentable?