There are many times that removal and replacement of Concrete or Decorative Stamped Concrete is not the only solution to settled or uneven concrete slabs. Settling generally occurs over time when the initial installation was improperly performed. The main cause for this is poor compaction of the sub-base or by leaving materials that can decay over time such as stumps or construction debris. As the materials decompose and rot they leave a void under the concrete that in time can cause settlement issues since the concrete has not support and settles unevenly.
The cost of removal and replacement can be costly and in many cases where there is active pedestrian traffic, that cannot be turned off, it can create a hazardous condition during the removal and replacement process.
Uneven concrete that has no cracks or few cracks can be returned to its proper elevation with a process called mud-jacking, slab-jacking or concrete raising. Where there are greater problems like excessive cracking this can also be done by filling the cracks after jacking. Sometimes cracks that are shrinkage related can be repaired more easily but many times will likely reappear. Movement cracks greater than 3/16″ wide usually can be filled but will return. If removing a hazardous condition is your main concern to reduce liability issues then just raising the settled slabs and filling the access holes will suffice.
The Law in most states views a difference from slab to slab greater than 1/2″ as a hazardous condition and requires businesses and homeowners to maintain their concrete to meet this specification. Reference ACI 318. If there should be someone that falls you can almost be guaranteed that this Specification will be posed as part of a lawsuit.
NOW FOR THE GOOD NEWS:
There is a little known or little used process that can be done using High-Pressure grout to raise the slabs back to their original elevations. The process involves drilling a series of 2″ holes in the slabs to be raised in such a way that the pumping of the grout under high pressure raises the slab or slabs uniformly. This grouting creates a new base by filling the voids under the slab. This will last provided there is no more rotting material under the slab. If there is a limited amount it usually is not enough to negate what has been done.
Sounds easy but it takes a lot of experience since if you raise the slab or slabs to high you don’t get a do over. Removal then becomes your only option. Once the slabs are raised the holes are then filled with concrete and finished flush to the surface.VOILA ! Like new at sometimes half the cost of removal and replacement.
What about the holes? I don’t like looking at them since the color doesn’t match the surrounding slab. There is a solution to this also, called Micro-Topping. There are many manufacturers of these products and the cost varies from one manufacturer to the other. We have found that we get the best results using Legacy Micro-Toppings and Stampable Overlays. The reason that we use this product over others is due to it providing consistent results. If you want further information on this or other products like this you can Contact me at Ted@split-rok.com
We are in the process of completing an 8,000 square foot job at Liberty Lake Day Camp in Bordentown, New Jersey. The Owner Andy Pritikin had been getting quotes last year for removal and replacement of the concrete around the pool at Liberty Lake Day Camp. We were called to quote the job but after meeting with Andy we decided that since his issues were related mainly due to settlement that the use of slab-jacking with a Micro-Topping would be the best Expedient and Cost-Effective Solution for his problem.
The reasons for using this method as a solution were many cost not being the only consideration.The pool interior walls were going to be redone at the same time that we were to raise and micro-top the concrete. The time frame was also critical since the pool had to be opened in time for the season and nothing but it being useable would do.
This job was in pretty bad shape. We called All Gentillini from Concrete Raising and he got all the slabs back in place in three days. 8,000 square feet in three days. Never would be possible with removal and replacement.
If we got caught with meeting an opening schedule at this point it would have been OK since the Liability issue was rectified. We then used a rolled on material called Rollcoat in a color that was selected by us to be light enough so as not to make the surface too hot from constant sunlight. This will be gone over with a Colored Sealer by Sherwin-Williams Company with Shark Grip added as another precaution against slipping.
The savings were approximately $40,000-$50,000. Nice savings in this economic environment. Not to mention the elimination of aggravation and messy removal to be endured with bad weather that time of year making the time element daunting.
Decorative Stamped or Colored Concrete can also be raised and the color of the hole, can in most cases be modified to make the holes less noticeable. It takes a bit longer to get the color of the holes to match, as close as possible but at Split-Rok Construction our motto is “The Difficult we do Right Away the Impossible takes a Bit Longer.
Think of a Stamped Concrete slab that has settled around your pool for example. No matter whether the concrete was colored in the truck (Integrally Colored) or installed using Color Hardeners the odds of getting a good match of the color is remote. Using color combinations and many years of diligent experience, we can usually get a color match that is so close that even the most discerning eye will have to work harder to see the difference. Not an exact match but in most cases more than acceptable.
DON’T REMOVE IT RAISE IT!
The cost associated with this procedure can save a company, business or homeowner a lot of money. It is also a winner where downtime in high-Traffic locations can cost money and unneeded aggravation.
Downtime is critical to any business.
There you have it. A Cost-Effective solution to either large concrete locations or small jobs where matching color is an issue.
I can always be reached at Ted@split-rok.com or visit our website at http://www.splitrok.com if you need further information about whether this an approach you would like to explore and a professional honest appraisal whether this will work in your situation.
Ted Mechnick (The Concrete Professor)