How can I remove 6 of concrete on a vertical surfa

Thanks

If time means nothing to you then I'd take a cheap skill saw and grid score cuts in the face then use a air chisle or hammer & chisel and bust the face blocks off.

I'd make a straight score line on either side to make it easy to keep the face uniform and under cut the face by atleast 1/4" then fill with a cement/sand mix to finsih to match the existing.

No Time then rent a concrete saw and make "one" cut to take out the bad section to the end then reform and pour.

Either way you look at it a bunch of bull work.

T_Bone

Why did you have to grind 1/16" off the surface? Was that a necessary part of the process or was there something you could have done earlier to keep from having to do it? (In other words, did you have to do it on account of an earlier mistake?) Like T_Bone, I've been interested in the idea of concrete countertops for a long time. Your description of your use of the kitchen, etc. sounds a lot like the way my wife and I live. I don't think we would have a problem dealing with the hardness of the surface; the hardness of the installation might be another matter entirely. I'm not sure there's enough cartilage left in my shoulder joints for me to enjoy that grinding part as much as I know I should.

All the best, Stan

I was thinking of doing the same here. A neighbor said he had tile counter tops one time and wouldn't have them again as they busted to much glass over the years. Same problem at your place?

He said it was mostly visitors that would break the glass from sitting it down too hard on the counter top.

T_Bone

I'd want to get more information before using percussion to remove material. It ought to be all right in the vertical plane but you're not going to feel any prouder of that wall if you put a crack through it.

Removing stock in carpentry, for inlet bracing for instance, I've set the blade depth shallow on a circular saw, made multiple passes however far apart the remaining wood would break off easily, then finished up with a hammer. You might be able to do that with a diamond masonry blade in a circular saw. If you could rig some plastic tubing to deliver water to the leading edge of the cut you wouldn't have to work in an abrasive dust storm or throw the circular saw away at the end of the job (my brother-in-law worked for a tile and marble company where they used circular saws for jobsite alterations, and the company bought Skill 77's by the pallet load---considered them disposable.)

You might rent one of those huge concrete cutting circular saws just for the single cut you could make the length of the bulged section and the depth of the blade. When you're removing concrete, any amount you can remove easily is a huge benefit.

I'd appreciate it if you'd describe your forms and tell me what you think went wrong. I'm currently in the process of forming up about 90' of 34" high retaining wall. My support system is slightly unconventional (and much, much more labor intensive than I'd imagined.) I think my system if going to be good but blowouts and bulges are what you always worry about, of course.

You can e-mail me or post on line if you wouldn't mind. I know that others will also benefit from the information.

All the best, Stan

Don't worry so much about the surface, you can easily clean it after the demo work, let it dry, use a concrete epoxy adhesive and parge ( face off like stucco ) the rough surface. It will bond much better to a rough surface, even if no adhesive is used, just make sure the rough surface is rinsed clean with water and moist if no adhesive is used and is parged over with a thin layer, you don't want the substrate ( existing surface ) drawing the water out of your wet material too rapidly. You can also attach some small mesh to reinforce the patch, like galvanized hardware cloth. That and adhesive, it will be a strong repair, just make sure all the mesh is buried evenly, you can attach with a powder actuated fastening gun, even small masonry nails, especially if not cured 100%, and while you do all this except trowel it on or fill a form, wear a good set of safety glasses, especially while chipping and whacking masonry nails. Hearing protection is also a must.

I'm sure you could also form it out and find a way to get the material inside the form. I'd imagine if you thought about it, and looked it over closely, you could re-establish the plane you want, like the rest of the wall, coat with concrete epoxy adhesive, place a form over the affected area, then place the concrete or mortar material, give the form a few whacks after placing material, to settle and dissolve any voids you may have. The form would have to be placed tight against the surface and you would have to over cut ( chip out 2-3" beyond the true surface plane you want ). Also have to settle the material 100% by giving it the form a few whacks, to be sure of no voids.

The color between the 2 will be off, and it may not be 100%, but the imperfections may be much smaller now, and more easily fixed, ground down etc. Wait 30 days for this to cure and use an epoxy strengthened or similar concrete paint or stain on the wall, it will make things look 100% better.

Other option is to chip off just enough and do something similar to a stucco or parge coat with the adhesive, mesh etc. Not so demo intense, either or, little elbow grease, imagination, using similar methods to above, you ought to be able make it look like you want.

Every so often you get a blow out, really have to brace uniformly and strong, sometimes you can let them be, but other times, I've tried to isolate the blow out, remove as much material that I can, straighten and re-brace the form, re-place the material, vibrate etc., Hard to stand there and just look at it. Big blow out, have not seen any of those on the large building jobs, form systems usually work well and are engineered, but at home when using lumber forms, much more common if not properly braced, little overkill is always good too.

6', not 10' of bulged wall, but you're probably right that repouring is the easier fix. My calculations say about 35 cu. ft of concrete to bring the whole wall to 12", and 9 cu. ft to repour the bulged 6' section. It would be less work to bring it all to 12" (unless you're mixing the concrete yourself) because the wall would only have to be formed up on one side this time. Removing 6' and repouring would mean about 13' feet of forms (you'd want some overlap) and nobody's idea of a picnic removing that section of wall, especially if there's steel in it as there should be.

Another alternative would be to step or angle a new pour from 6" to 12" at the 20' mark so that the front 6' of your wall would be 12" thick and it would look like you meant for it to be that way. Whenever I wind up with a non-structural mistake in a project, I always try first to see if there's a way it can be modified to become a design element at less total work than correcting it. If you repour to make the whole thing 12" thick, you're going to get asked about it every time anybody sees it for the first itme. Ask them to guess why you did it that way and I'll bet you get a lot of bizarre answers.

Good luck, Stan

Or maybe use some other means of making it disappear, lattice board, stacking rocks, who knows....