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The customer had a concrete porch installed a year or two ago. Contractor sanded the steps. Looks like hell. She wants a smooth surface. My first thought is that a grinder (seems like I’ve read such an animal exists on this board) would make short work of it, but can a grinder get the full 11″ step? Also, the guy sanded the riser as well as the step. Grinding the riser sounds awkward? Just two 11″ steps and two 6″ risers. Steps are 64″ long.
I’m going by the rental place today and they may have an answer, but I thought I’d ask here just in case.
Rich Beckman
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Smooth finish concrete? Treads and risers? Outside?
I know you know better Rich, but this would be a good example of when not to give the owner what they want. First bit of wet gets on that slick surface and her attorney will be calling you from her hospital room.
*Rich,That was the first thing I thought of, and I pointed it out to her. But I am hard pressed to think of a concrete step in this town that isn't smooth, so I am not sure there really is a liability issue. Smooth steps seems to be the standard.Rich Beckman
*So, Rich- What did you find out about grinder at the rental place? Just curious. -Ken
*Rich,Smooth seems to be the standard here also, unlass it is exposed agregate(sp).
*Oh, right. They suggested an angle grinder (I forget the size, but it was bigger than the 4") with what he called a grind cup (I think). The grind cup is specifically designed to grind down concrete and is only about 4" in diameter, so I don't fully understand why the larger grinder is needed (can't believe I didn't ask that!)The cup must be purchased ($15.00) and then the grinder rented for the day ($25.00) or the hour ($5.00). He said that if it took more than half a day I would most likely be ready to give up anyway. I suspect that it would only take an hour or so, but I will bid it assuming an afternoon.I do think I'll chat with my insurance agent before I bid it.Rich Beckman
*Okay, let's define "smooth". To me, smooth is that blued slick troweled finish. You know, when the pour is worked so much that the metal trowel begins to blue at the edge of the blade because of the heat.Smooth as glass. This is the texture of the stoops on our house. Thankfully I buried them under a wood deck.
*customer won't consider painting the steps?brian
*How rough is it? Too much grinding and you've got terrazo (it doesn't take much).
*How smooth?? I'm not sure. This is new territory for me. Ideally, I get the sand off and leave a surface that feels a bit rough, but looks smooth (if that makes sense).JCallahan,Excellent point. Thanks for reminding me.Again, if I can just get the sand off (or enough of the sand off) so that the surface is visually consistent accross the whole area of steps and risers, I think that would be satisfactory.Rich Beckman
*Rich, do you have a belt sander? If so, use a couple 50 grit belts on it, the purple ones instead of the cheap brown kind. The blue ones work even better, but they are too expensive to be worth it.I've sanded small patches of rough concrete this way. I hope you don't have enclosed steps.
*i Contractor sanded the steps.I guess I should have understood your post better. Now that I do, I like Brian's idea of painting (adding a layer) more than grinding (deleting a layer). Going with Brian's idea perhaps you should consider adding a layer. Doesn't have to be paint. Add a skim coat of portland slurry or something like that. Seems like it would take alot of work to get a consistent finish on all areas of treads and risers if you were to grind.However, you may have a problem with spalling if subjected to freezing. Anyway, just a thought.
*Rich,Be carefull if you use a cup grinder. They are a real bear to control, and tend to gouge when you get them tilted off angle just a bit. I like sg idea of the belt sander. I used one to resurface an old terraso floor once (64sf) and it did an excellent job.
*RichIs this an epoxy coating system?If it is epoxy is not very heat resistance. At a couple of hundred degrees they break down.I wonder if a torch or even a heat gun could be used on it and then just peal it off.
*Bill,No, I don't think this is any fancy coating. It looks like nothing more than sand tossed onto the surface of the wet concrete.As I read these, it occurs to me that the cup grinder isn't going to get into the cove(?) of the step/riser. At least not mounted in the angle grinder he presented (there is a rather large shield). In fact, I'll bet it's gonna miss a full inch on each side of the cove. Makes the belt sander sound better.Any other thoughts?Rich Beckman
*After you get through belt sanding, cut the worn belt into orbital-sander-pad size and do the coves with that, or any other areas you missed, for that matter.....God, this reminds me of my first shop covered in drop-lap siding that i sanded to 120, coves and all.
*Without seeing it I can't say for sure (kinda like doin' mail order brain surgery) but what might work is an acid etch done with a stiff bristle brush. Rinse well and after it dries go back with Splintie's sander.
*sander sounds good.. but what about a standard concrete rubbing block? Only 2 stairs and knocking the sand off can't (?) be that tough an issue.
*You obviously haven't met Rich. Couple of steps with a hand block and, uh, well, uh,..................
*Ditto Richeson's comments. As soon as you get the cup flat enough to do a smooth surface, it'll catch on an edge and kick and dig in, leaving a nice mark. Over and over. Surely someone who uses them daily would have better luck, but I'd also go for a belt sander and waste a few sheets of sand paper. Rubbing block is cheap and worth a try, too.
*Sounds like astro-turf time. My parents had problem with thier conrete steps and instead using my advice to coat the steps with an epoxy or start over they had astro-turf installed. They love it and I cringe every time I have to use the front door (holidays only).
*> a standard concrete rubbing blockI've never heard of a concrete rubbing block. I think I might start with that and a wire brush, no acid. See what that does.I'll find a rubbing block, think of a price, chat with the customer and see what happens.I'll let you know.Thanks everyone.Rich Beckman