CONCRETE ADVICE NEEDED

We have a pool with a concrete or cement walkway around it that is appx. 36"
wide. We need to get to a leaking pipe underneath this walk.
I may want to jackhammer the concrete above where the pipe is leaking.
How can I saw this walk which is about 3" thick so that the jackhammer
doesn't crack it into jagged pieces beyond where I want to get to?
Thank you.
j/b
Reply to
justme
Loading thread data ...
There are dry diamond saws that will work on a Skil Saw. There are also ones for angle grinders, but my grinder is a 4 1/2" so you could only cut about 1.75" deep.
Reply to
Calif Bill
Check with your local rental yard. You need to saw the border of the area to be removed, and break the center.
You may be able to score the walk with a skill saw, and break it gently with something like an electric jack hammer. If the concrete is not sawed all the way through, you stand a greater chance of breaking the part you want to keep if using something aggressive like a sledge hammer.
If you rent a saw that will cut the concrete all the way through, you should be able to break the concrete any way you choose.
If it's just 36" wide, it might be less work to tunnel under it. Sawing, breaking, reforming, mixing and finishing concrete is pretty time consuming. Plus you will always have an area that doesn't match the rest of your walk.
Reply to
Tim
Dead easy - get a masonry cutting blade (doesnt need to be a fancy diamond one, plain abrasive masonry cutoff disc will do ) for your angle grinder. Preferably a 9 inch angle grinder (which are ridiculously cheap anyway, and are a mighty tool for, well, cutting anything with the right disc) You don't need to go all the way through, at least half way (or more if you can) as the fracture line when breaking it up will be below the cut line.
Reply to
Andrew VK3BFA
You can rent a saw for the job. Should be a one-day deal, so it should not cost too much. If it does cost too much, you can get a dry diamond blade and use a saw not really made for the job - either buy a cheap POS for the job (ie, the rental must really be overpriced) or have someone stand there with a shop-vac to suck the dust up as you cut - otherwise it gets into the saw motor and will kill it over time. You don't really need a jackhammer - a sledge, or a sledge and a chisel, or (with a good cut and a fairly small area) simply a prybar to lift the affected area.
If the concrete is steel-reinforced, it may not be very kind to a dry diamond blade, but if you're using an electric saw that's not specifically designed for use with water, wet cutting might just kill you - at which point rental of the right saw begins to look more sensible again.
If the pipe is in the middle of the walk (or closer to the outside edge) digging a big hole may be a lot simpler than cutting the walk at all. If you do cut the walk, make the replacement section able to be lifted out the next time the pipe leaks.
Reply to
Ecnerwal
Thanks, Bill. I'll look for one.
j/b
Reply to
justme
Tim, we have tunneled under the walk but it is getting tougher to do. I am going to 'auger' it with a gasoline 6" auger and see it we can get more dirt out to gain space.
Doing the concrete is the last resort.
Thanks for your help.
j/b
Reply to
justme
Okay, Andrew. I will see what I can get a 9" grinder for. Maybe H.F. has a cheapy.
Thanks for the tip es 73.
j/b
Reply to
justme
Ok, Lawrence.
I will check to see how much a rental saw will be.
I am considering cutting the concrete as a last resort.
I appreciate your input.
j/b
Reply to
justme
I once saw a guy dig under a concrete walk to get to a leaky pipe, but of course the access hole was significantly bigger than if you just cut the concrete.
As far as busting it up, just hire somebody with a concrete saw, and take out the whole chunk, then replace it after preparing the substrate.
Good Luck! Rich
Reply to
Rich Grise
If you try tunneling a hole under the pool deck or sidewalk from the outside, plan on replacing the entire slab in a few months anyway. It will sag, and it will crack, and in totally random patterns.
There is no way to get the compaction of the fill dirt right when you backfill the hole - short of filling the whole thing in with "One Sack Slurry" or "Two Sack Slurry"which is (as it sounds) a varying strength concrete and sand mix.
And even then, if you get any voids in the backfill it's going to settle and break.
And if you backfill with a cement sand slurry you will play hell getting to that pipe again next time. Think 'encased in sandstone.'
Can't win for losing anyway... Murphy's Law says that the dirt /around/ the area you patched will settle differently than that big block of concrete you poured, and the pipe breaks at the parting line.
Do it right: Rent a concrete saw. Saw cut and remove a chunk of sidewalk/deck, do your repairs, put the dirt back and compact it properly as you go, then place a couple of strips of bender-board as expansion joints and re-pour the slab.
-->--
Reply to
Bruce L. Bergman
Totally false, I have done it many times. Yes, you should tamp the earth back in place, but it can easily be done.
Reply to
Tim
Bruce, thanks for all of that info.
What happens if I refill the tunneled hole with sand?
j/b
Reply to
justme
Rich,
There is the pool then about a three foot wide concrete walkway and then 2 feet of crushed limestone and then a natural rock wall and all of this is the perimeter. I have a large backhoe but I can't dig under the rockwall without destroying the wall.
Oh, I can't afford to throw dollars at it.
j/b
Reply to
justme
Just put the slab back like a big stepping stone.
Reply to
Calif Bill
Very sage advice!!
'In the first place, we should insist that if the immigrant who comes here in good faith becomes an American and assimilates himself to us, he shall be treated on an exact equality with everyone else, for it is an outrage to discriminate against any such man because of creed, or birthplace, or origin. But this is predicated upon the person's becoming in every facet an American, and nothing but an American... There can be no divided allegiance here. Any man who says he is an American, but something else also, isn't an American at all. We have room for but one flag, the American flag... We have room for but one language here, and that is the English language.. and we have room for but one sole loyalty and that is a loyalty to the American people.' Theodore Ro osevelt 1907
Reply to
Gunner Asch

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.