Concrete Floor Pitting Repair

In this video we cover the basics of repairing pitting in concrete floors. It involves the same steps we've covered in other videos about repairing cracks: expose, clean, rinse, patch, and dry. WEAR EYE and HAND PROTECTION!
Tools suggested:
3 lb hammer
Masonry chisel
Wire brush
Vacuum Cleaner
Margin trowel
Rubber grout trowel (float)
Spray bottles
Buckets
Funding for this statement, publication, press release, etc. was made possible, in part, by the Food and Drug Administration through grant PAR-16-137, by grant number 2020-70020-33003 from the USDA National Institute of Food and Agriculture, and by the National Institute of Food and Agriculture, U.S. Department of Agriculture, through the Northeast Sustainable Agriculture Research and Education program under subaward number LNE-19-375. It is offered without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, protected veteran status, or any other category legally protected by federal or state law. The views expressed in the written materials or publications and by speakers and moderators do not necessarily reflect the official policies of the U.S. Department of Health and Human Services or the U.S. Department of Agriculture; nor does any mention of trade names, commercial practices, or organization imply endorsement by the United States Government.

[@boots7859]

Only thing I think was missed was adding a bonding agent of some sort which will help the new concrete/mortar bind better with the old crete.

[@uvmextageng]

I believe the product used has a bonding agent included, but would have to check. The thorough chiseling and cleaning ahead of the repair is the key in my experience. That helps ensure there is a solid and clean foundation to bond to.

[@nmssis]

thanks for posting. How important is the cleaning...some that have done this, say it is important but others say it is not.

[@uvmextageng]

In my personal experience, I have found the cleaning to be very important. Especially for heavily trafficked areas. For one thing, a clean surface will bond better with new material. If it is highly trafficked there are likely deeply rooted soiling and perhaps oils in the concrete that cleaning will help to remove.

[@nmssis]

@@uvmextageng any suggestions for oil stains?

[@uvmextageng]

@@nmssis the cleaner featured does a pretty good job with them. Multiple applications, scrub, rinse, repeat. Like doing greasy dishes. Go until you have white lather and bubbles and clear water in the rinse. Check out the guide sheet on our website.

[@nmssis]

@@uvmextageng thanks will give it a go

[@boots7859]

LOL, did you actually watch the video where he explained, a couple times, why cleaning is one of the keys to getting a successful repair?

[@JohnGraham-wb6el]

Do you have a list of the products you used ?

[@uvmextageng]

That's a good idea. The two main products used were (1) Quikrete Concrete and Asphalt Cleaner Concentrate and (2) Quikrete Quick Setting Cement. More information at blog.uvm.edu/cwcallah/2021/08/04/repairing-cracks-and-pitting-in-concrete-floors/

[@JohnGraham-wb6el]

Thank you!

[@jamieg9267]

Should you pressure wash it for cleaning or does that just cause more damage

[@uvmextageng]

Our focus was on concrete floors in produce handling areas. So we avoid pressure washing since it can lead to contamination. If you have another type of space there is no reason not to pressure wash. Anything that pressure washing (or wire brushing, etc.) takes off is bound to come off at some point anyway. The point is to get to freshly exposed, solid, clean concrete in order to build it back up with a strong bond.

[@grantmurphy7965]

Do you ever use bonding agent?

[@uvmextageng]

We have not.

[@cheetahlip]

What’s the brand of that cleaner?

[@uvmextageng]

It is a Quikrete product. More info: blog.uvm.edu/cwcallah/2021/08/04/repairing-cracks-and-pitting-in-concrete-floors/. It is the item labeled "A" in the figure there.

[@cheetahlip]

@@uvmextageng thanks for the quick reply!

[@michaelwarren5084]

I am used to fixing potholes on an asphalt roads..... And I will typically cut the asphalt back to solid foundation...
Would that be a terrible idea to do with something like this?

[@uvmextageng]

It's not a bad idea. That's essentially what the chiseling is doing, but you can do it by cutting if you have the equipment.

[@jje984]

Could you just skim the whole surface with concrete to get a uniform look?

[@uvmextageng]

It seems hit or miss and mainly miss with that approach. A very thin layer of new repair cement / mortar (not concrete) over an older, exposed, and weathered surface will likely not bond very well. The point of chipping it back is to remove any loose, weathered, dirty and weak material to ensure a strong bond of the new material. Cleaning and etching may result in a satisfactory bond of new with old, but still with a very thin new layer over an old layer I wouldn't expect much life to it.

[@mattgrizz1153]

Rapid set cement all instead of this!

[@uvmextageng]

I’ve found the surface preparation to be critical for a long lasting repair. We do use fast set repair mortar and cement.

[@sittingduckass3676]

How well has this held up? Has it cracked at the edges where the concrete is thin and blends in with the old concrete?

[@uvmextageng]

It has held up remarkably well. No cracking or chipping at the edges. I was really worried this could happen, but not yet. Two years on with heavy daily foot and handcart traffic. No signs of wear. I think the thorough chiseling and cleaning is really important. You need a very solid and clean foundation to work from.