Can concrete be lifted to remove roots and then be laid back down? I get this question at least once a week. Roots and concrete don’t play well together. Sidewalks, driveways and garage floors get lifted by roots all the time.
Tiny roots venture out looking for water. Most of the roots we find when we remove the concrete are less than 1/2″ in diameter. The one or two roots that found the water supply have done all the damage.
So can we lift it up, cut the roots away and then lay it back down? Unfortunately that doesnt work well. Concrete is too heavy and too hard to make it feasible. To lift even a single section of sidewalk you need a machine or strong backs. It may take several ups and downs to get the elevation just right. Doing that without breaking it can be a challenge because it is hard to the point of being almost brittle. Then after all that it still may settle.
We normally break the concrete up with a sledge or jack hammer. We break it up small enough so it doesn’t cause any long term damage to the guy’s bodies. Once the concrete is out of the way we go to work on the roots. If you don’t dig deep along each edge and find the roots further below the surface the fix may end up being temporary so we dig down 8″-12″ to locate as many as possible.
Once the roots are gone the base needs to be properly compacted to assure the new concrete won’t settle. We often install a polyethylene expansion material at one end and then pour the new concrete so it will match the height of the existing slabs perfectly.
If your HOA is breathing down your neck grinding can work in some cases but we don’t recommend it if the trip lip is over 3/4″ high. Also know that without digging up and cutting off the roots the fix will only be temporary. Just fixing one or two sections won’t be the most cost effective solution so it may be a good time to add onto the patio or put a pad under the garbage can.
Thank you for taking a look
Jon Molden
BST Concrete