There are contractors that lift the everyday slabs, performing a great service fixing trip hazards, reviving previously unusable floor space, and supporting the investment of the property owner. Then there are slab and foundation lifting contractors who take it to the next level – every opportunity is a challenge to be conquered. The results are often fantastic – people’s entire homes lifted back into place, factories and warehouses returned to life, and countless potential hazards and injuries avoided.
But first you’ve got to understand one thing; you can’t bring a knife to a gunfight. Expert contractors have to know what is going on at all times. In the picture at the top of this post, you can see a slab that I probably would have not attempted to repair. However, with several tools to help monitor the different pieces of this puzzle, this contractor was able to put it back together again. They say information is power and I am a firm believer in that, especially when it comes to taming jacked up concrete slabs. In the picture you can see three different slabs. Our customer Morgan Helms of Helms Polyfoam (Jackson, MS) is using a ZipLevel, a machinist’s dial indicator, and a putty knife to monitor what each of the slabs is doing.
The MixMaster gun is injecting underneath the slab that he wants to raise.
So what are these different monitoring tools doing? Let’s take a look….
- The dial indicator tells him which slab is moving. In the picture, the base of the dial indicator is on the slab that Morgan is injecting under while the dial point is on the slab he doesn’t want to move. It doesn’t really matter how you configure it as long as you understand what the needle movement means. A needle on a machinist dial indicator moves in .001” increments. If the needle on this dial indicator is rising, that would mean the wrong slab is lifting and he knows to stop. If the needle is falling then the slab he is injecting under is lifting, and that’s what he wants.
- So what if both slabs are moving equally? In that case the dial indicator would remain stable or fluctuate slightly in both directions. This is where a ZipLevel or a laser transit would come in handy. Morgan has his ZipLevel indicator box (in yellow) on the slab he doesn’t want to move. It will let him know if the slab he doesn’t want to move is lifting so he can stop and re-evaluate what to do next.
- One of my favorite tools is the metal putty knife. Slabs often move in increments so small that you can’t detect them visually. If you wedge a putty knife into a crack between two slabs, you will see it wiggle when there’s slight movement. So the putty knife in the picture is on the third section of slab and letting Morgan Helms know what is going on with that piece.
You can use other things like string lines, tape measures, and laser transits as well. The point is that real time information is likely to give you a better finished result, and it will also help you avoid making mistakes.