106

Move the hole. You know its in a bad place. If you break the pipe with your flag pole you will curse your own stupidity and hate the flag pole and that is how bad things start. If you do get away with it then someday in the future someone will try to remove the flagpole and break the concrete, and they will drive the concrete into the PVC and then track ...


35

That looks like a very poor finishing job to me. I've assisted on many driveways and never had to go back with a grinder. Finishing it wet is all it takes and leaves the desired surface that isn't slippery. Watch them carefully and hold off on final payment until you're satisfied with the job.


31

Never, ever, mess with any pipe underground. No matter if it is any kind of plastic, steel, brass, copper, ceramic, concrete, whatever. No matter if it is used for sewer, water, gas, electricity, Internet connection or underground smuggling of rocket parts (it happens!) or vodka (it happens, as well). Pipes sometimes break after a while even when left alone, ...


25

Yes, you should be concerned. Cracking like this is caused by movement (the structure has moved, such as settled) and this type of cracking is unusual. This needs to be reviewed in person by a structural engineer who can look at the particulars of your situation. This is not something that you can get a good answer for here on this or other sites. FWIW, I'm ...


24

Jack has a good answer but want to add. This strikes me as a concrete job done after they did another with whatever was left over. If the mix is that dry there could be major long-term issues. From your picture (and I know its a picture and I am not there) it looks like that mix was never wet enough. You simply don't get "crumbles" with ...


24

My layperson's view: The link between silica dust and lung cancer exists primarily in industrial settings (mine, refinishing, construction). The people who grind down the concrete in their usual workday are the ones who are at risk. It's a occupational risk. After proper cleaning, as you have done, the risk is low to the resident. Concrete dust settles well: ...


19

Great answers here already. To add... The seam between the current concrete that's "set", and the new surface concrete they plan to pour, is referred to as a "cold joint". It's true that concrete continues to cure over time (the molecular crystalline structures continue to grow outwards, which is why you continue to water fresh concrete ...


18

You could have caulked them a month after the slab was poured. You can caulk them now. Or vacuum/scrape them out and caulk them now. Saw-Cut control joints (as opposed to "tool-formed while the concrete was wet" control joints) are inherently sharp. They are less expensive than formed joints. They need to be deep enough to accomplish the goal of ...


17

There are really only two solutions from a aesthetic standpoint: Coat the entire slab with a surfacing product (which may or may not conceal the crack for the long term--depends on seasonal/traffic movement) Replace the slab You can't visually "fix" cracks like that in concrete. The color and texture will never match well, making the situation ...


15

If you want no holes, you have to compact it, easiest is with vibration but that needs a special tool. Or you can poke a stick in and out of it for a while. I've had great success by fastening a bit of wood plank on the business end of a vibrating sander and using that as a vibrating float. Don't worry though, you're not building a suspension bridge, it's ...


14

The concrete looks intact enough for re-use, I can't see if the anchor bolts are good or not, if they can't be reused getting old anchors out of concrete can be tricky: you might have to move your letter box one inch to the side so that new anchors can be drilled into virgin concrete. If you do move it don't leave the old anchors protruding they are a trip ...


14

If you wanted to keep the post centered in it's current location, you could rotate the post 45 degrees and re-drill in place. You might not even need to do anything to the old bolts, as it's unlikely to be a tripping hazard so close to the post. You'd probably have to add a plywood mount at the top to rotate the mailbox back to perpendicular to the street, ...


13

Summary - the post size seems questionable. Even at 12", it might have been insufficient. It depends very much on your soil type. The remainder of this answer is a huge estimate based on lots of assumptions. For something like a residential deck the reason the size of a footing is important is not because of the strength of the concrete itself, but ...


13

It's not a major hazard (unlike asbestos). If you live in a big city, its not uncommon to find your car coated with similar dust from construction and demolition work. The risk is primarily to the construction workers who are continuously exposed to such dust in the air throughout their working lives, and to miners with much greater exposure in the confined ...


12

For consideration Once you buy the water trough you are done. They come in a range of sizes. They will hold water a long time. They are not expensive. In the desert where you live there will be a store for people who keep animals and you can look at troughs there. If the trough you like stands too high, set it down into the ground a few inches. If you ...


11

Delivery of ready-mix in a truck This gets you a whole lot of mud fast. There are a couple of problems: First, the "short" (small) load fee may raise its cost by 50% compared to the per-yard price you were quoted. Second, they'll likely allow you something like 5-10 minutes per yard to unload the truck and may charge by the minute if you run over ...


11

TL;DR You shouldn't do that. If for no other reason then consider this simple fact. If that pole gets knocked over via wind or a rogue vehicle then the concrete will tilt and puncture a hole in the PVC. Now you have two problems.


10

Sounds like a hack-job approach to me. That wall could be built from concrete blocks (aka CMUs or concrete masonry units), with bond-block rows and reinforcing steel, and grouted full, making it effectively solid, without abandoning forms in place - or rather, the forms would be the block wall. Of course, poured concrete contractors and masons are not ...


10

You should use an abrasive grinding tool with a relatively fine grit or tooth, not a cutting tool. You don't want anything that can catch the tile and shatter it, and you want to operate at a fairly high rpm to reduce chatter and grab. Apply pressure parallel to the face of the tile only--don't push inward or outward or you risk spalling the face of the tile....


10

Sleeve It When running any tubing (PEX, ABS, PVC) through concrete you need to de-couple it, Even 6mil plastic suffices, but sill guard is better. A tubing sleeve (e.g. 1.5in ABS) like you propose through the wall, is good too. Hot and Cold You can run PEX under ground. I have done this successfully. Hot and cold to the exterior, then cold to an out building....


9

Being a corner and a mid block crack I would say yes there is an issue here. It could be the attached building footing sinking but mid block cracks are really bad I have only seen them in walls that were not properly filled, or some that were not filled at all. But a mid block fracture over this many layers or courses needs a engineering review and proactive ...


9

Finishing does not just make the concrete look nice - it surfaces the 'cream' - it makes the cement come on top to make it stronger. Each hour, the top should be resurfaced to drive out the excess water reduce cracks. You should NEVER lay new concrete on top of dried concrete. (Unless each slab is thicker than 3 inches and you use rebar to bind the layers)....


9

Don't try to make it look "even and uniform". Instead, have some intentional decorative feature that camouflages or hides the difference. For example, rather than repainting the entire driveway after patching the crack, you could paint some fantasy vines on the driveway, where a vine matches the position of the crack. This is a general idea of a ...


8

Ultimately, I decided to save it. I used stacks of cribbing with large beams to jack the building up off of the failing foundation walls. Similar to this (much larger) example: Once I had it up on the crib stacks, I was able to remove the jacking beams, pour concrete footers/piers, and set 6x6 posts. The building now rests on those posts and sits firmly. ...


8

If the concrete has "expired" before or during the pour, I believe that concrete needs to be completely removed and redone. Expired concrete will not cure to "design" strength. I would ask the contractor remove all of the concrete to restore the site to the condition before they arrived and for a total refund. Then I would find another ...


8

All of those methods do the same thing. The sealant method is done one time, no additional sealant needed. The water spray method needs to be done regularly, maybe every hour or so. The dam method has time involved for making the dam, but does not need to be maintained as much as water spray. All these methods are done only after the last troweling is done ...


8

I want to thank all of you for your suggestions! I was fortunate enough to run into a contractor that was working on another project in my building. Turns out, that there is no rebar, wiring or plumbing of any sort where I wanted to put up my shelves. My settings on the SDS Hammer Drill were correct. The problem was, that since the drill was new, ...


7

Not poured wet as noted above, the strength of the slab on grade will be compromised. Strength is directly related to length of curing time. Such inexperience also calls the installation of reinforcement into question. Ordinary concrete mixes or cement cannot be used as an "overlay" or skim coat as it requires much thickness for strength. Specialty ...


7

So the question is it a live joint? A live joint is one where the ground is actually moving, and you can tell by careful examination of the bottom of the control joint. If there is no crack in the bottom of the control joint it is not live and can be filled with either mortar or caulk. if there is a crack in the bottom it is easier to assume that there is ...


6

Check with a termite control company and/or the state agency that studies termite control. Also check with your homeowner's insurance company. Having all that buried wood would invite termites.


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