You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Ground Penetrating Radar cost?
- Thread starter TRX
- Start date
Fix Until Broke
Well-known member
Here's a video of an area where I know there's a hollow spot on my patio. It didn't come through as clear as it sounded in person, but it's worth a shot...
rustyjames
Well-known member
Drilling some 1/2" holes and probing with a rod is going to tell you the same thing as core drilling.
Jrad235
Well-known member
This is better than mud jacking. Mud jacking doesn't compact the loose fill where the tree roots have rotted.
Bill
Bill, proper mudjacking (Not poly foam) is pumped at ~200PSI. with the proper slurry, it will find and fill ALL the void, plus compact any loose **** underneath.
Hooked
Well-known member
Dragging your floor jack across the area will give the same (possibly better) results as the chain.
So, returning to the thread, I bought a big DeWalt "rotary hammer drill" and a bit rated to go through rebar and drilled holes in a 3x3 foot grid across the 20x35 floor. That's a lot of holes.
WIN: the rotary hammer drill is awesome. It has a spring-loaded handle; you put about five pounds of pressure on the drill, and it takes about thirty seconds to make a 1/2" hole.
WIN: I got the 8 inches of concrete I paid for. Maybe 7" in some places, maybe 9" in others, which I figure is close enough.
WIN: I hit rebar every second or third hole. I paid for "double rebar." I saw them start wiring up rebar before they poured, but I didn't see them finish before I had to go to work. Looks like they did a good job.
WIN: even with all the holes and rebar, the Bosch SDS drill bit seems as effective as it was when I started.
WIN: there's no noticeable hole where the tree stump is/was
WIN: the back 10 feet or so of the slab is on a road; it's all good there
LOSE: the front 10 feet of the slab was on "Donnafill" over whatever had been used to fill in the ditch in the late 1940s. The fill has subsided under the whole front of the slab, *except* for the outside edges. The gap seems to average about 3 inches. I carefully broke through the bottom of the slab with the drill, then used a steel rod with a T-handle to probe underneath.
LOSE: that's a large volume under there, which the local slabjackers feel is worth about $2,500 to fill.
[sigh]
WIN: the rotary hammer drill is awesome. It has a spring-loaded handle; you put about five pounds of pressure on the drill, and it takes about thirty seconds to make a 1/2" hole.
WIN: I got the 8 inches of concrete I paid for. Maybe 7" in some places, maybe 9" in others, which I figure is close enough.
WIN: I hit rebar every second or third hole. I paid for "double rebar." I saw them start wiring up rebar before they poured, but I didn't see them finish before I had to go to work. Looks like they did a good job.
WIN: even with all the holes and rebar, the Bosch SDS drill bit seems as effective as it was when I started.
WIN: there's no noticeable hole where the tree stump is/was
WIN: the back 10 feet or so of the slab is on a road; it's all good there
LOSE: the front 10 feet of the slab was on "Donnafill" over whatever had been used to fill in the ditch in the late 1940s. The fill has subsided under the whole front of the slab, *except* for the outside edges. The gap seems to average about 3 inches. I carefully broke through the bottom of the slab with the drill, then used a steel rod with a T-handle to probe underneath.
LOSE: that's a large volume under there, which the local slabjackers feel is worth about $2,500 to fill.
[sigh]
Fix Until Broke
Well-known member
Well, now that you have a nice grid of holes there (good work by the way!), I wonder if you could slurry some sand in through those holes to fill the void underneath?
In2toys
Well-known member
I'm sure this post will start a $hit storm but...I tear out concrete for a living. when I tear out something that has been mudjacked, sometimes it's just what the name suggests. Mud. Its hardly ever hard. Point being ask a lot of questions of the mudjacking guys
Jrad235
Well-known member
TRX, that seems a tad high for traditional mud, do you know if you were talking to polyurethane foam slabjackers? I would think for that size area(10x35) you would be closer to $800-1500 for that void with traditional mud slurry.
In2toys, some mudjackers don't use a proper blend of materials, leading to a slurry that doesn't set up correctly. That's good for you though since I'm guessing that concrete you tore out had re-settled? What is your experience removing and disposing of concrete that has been poly lifted?
In2toys, some mudjackers don't use a proper blend of materials, leading to a slurry that doesn't set up correctly. That's good for you though since I'm guessing that concrete you tore out had re-settled? What is your experience removing and disposing of concrete that has been poly lifted?