New Concrete Finish Coming Off - Why?
New Concrete Finish Coming Off - Why?
(OP)
I am not a concrete expert, but a sub contractor had poured this new floor 6 days ago and now the top finish is coming off in about 6 areas in a 5,000 sf floor. The floor is a 5" thick 4,000 psi mix and the floor has a 12" compacted gravel base, plastic vapor barrier, 2" foam insulation with in-floor heat tubes and #6 wire mesh. The concrete was poured in good weather 70-75 deg partly cloudy no rain. The concrete was placed using a pump truck and finished with a ride on finishing machine. Please see the attached photos.
Is it possible that they worked it to much and dried out the top?
Any options for a repair? This is a shop type of building.
Thanks in advance for any help.
Is it possible that they worked it to much and dried out the top?
Any options for a repair? This is a shop type of building.
Thanks in advance for any help.






RE: New Concrete Finish Coming Off - Why?
http://www.cement.org/docs/default-source/fc_concr...
This one uses at least one of the same picture of blistering, and also seems concerned about placing concrete over a vapor barrier.
http://www.rcil.ca/pdf/Power%20of%20Concrete%20-%2...
RE: New Concrete Finish Coming Off - Why?
RE: New Concrete Finish Coming Off - Why?
RE: New Concrete Finish Coming Off - Why?
It can be repaired but if there will be abrasive traffic on the floor, it will be a constant maintenance problem. Scabble the surface to a depth of at least 3/4 of an inch or to sound concrete if still friable. Top the floor with an abrasion resistant topping like SikaTop or MasterPlate.
RE: New Concrete Finish Coming Off - Why?
Professional and Structural Engineer (ME, NH)
American Concrete Industries
www.americanconcrete.com
RE: New Concrete Finish Coming Off - Why?
It sounds like the sun came out and the wind picked up and it set up quickly and they used some cream and a bit of water in a few spots. Which usually doesn't work out so good.
It seams like there is more of a chance to get a bad finish when you pour on foam insulation.
Thanks for the help.