New Concrete Floor laid, cracking, and sealer Q's.
Our company just purchased a 44,000 square foot building PA which was nearly complete at the time of purchase. The original builder was contracted to finish the building for us, and recently finished pouring the warehouse concrete floor. It is a 6" floor.
The areas that are not laid are because they are part of a different phase of work, office fit out, and the plumbing isn't in yet.
I am concerned because this brand new floor (3 weeks) has long cracks that travel through the expansion joint. The builder told me that it is common, and it happened when they saw cut the joints. Some of the cracks are large.
Also, one crack occured at a merge between a previously laid area (under block demising wall) and new floor area.
We also paid $8500 to have the floor surfaced with a floor sealer called SEALHARD, which is a LMCC.com (L and M construction chemicals) product. When I spoke to L and M, they said the floor would come out looking great, and that the product has a huge cosmetic advantage over a standard floor. I really had little interest in the anti dust effects of this, and was hoping for a brand new clean looking floor after the sealer, but it appears even worse than regular concrete. They even started and stopped the "polisher" or buffer in one area and it looks like a huge mess.
The builder says the chemical was installed correctly, end of story (I'm not so sure?). The builder says the cracks are going to be grinded and dry patched.
What do I deserve though?
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Also, one of the picture shows that on some areas of the concrete, the top surface is cracking away like an eggshell. I've never seen this before, what is it, and is it indicative of a bad concrete job?
That is one ugly floor! Send the pictures to the coating manufacturer and see if they agree that it was properly done.
I'm pretty sure the crazing appearance of the concrete surface is not a big deal structurally. Somewhere I read it's caused by the very thin surface layer drying too fast instead of curing.
The big cracks look like they started before the control joints were cut (i.e. the control joints were cut too late) or else the control joints weren't cut deep enough to get the cracks to follow them. Hopefully everything was compacted properly and the cracks wont get worse.
Also, are these expansion joints supposed to be filled with a caulk? Our current building, they are caulked. When would I normally expect that to be completed?
Some of the cracking was shinkage and some are concrete settleling both are unacceptable for a new application. shinkage is due to lack of preparation on the curing of the concrete. settleling of the concrete is due to poor substrate compactation. the sealer might have been installed before 28 days according to some manufacturers specifications.
The concrete was overworked and the joints were cut late and in the wrong place, but it is only an esthetic issue, bottom line. The hardener appears to have been applied too early, but that ties with the overworked finish, and should not effect the durability.
dont give that a dime till the floor is perfect... id love to see pictures of it ever being perfect... they might be able to seal and cover it up but i would say those crack will for sure come back to haunt you
Anyone see a crack in 6inches of concrete like that??? there is no turning back from that one my friend!!!!! get ready to fight the never ending battle!!!
Too much concrete not enough guys that know what their doing to place and finish. Sealer installed way too soon, concrete is still curing and now someone just sealed in the moisture trying to escape.
Those control joints are in the wrong spot(s). Have him fix it and not using drypack, you think it looks bad now? I'd hate to see his version of crack repair.
If you want to leave it and make it look good, strip the sealer, let it cure out and then acid stain it, all the cracks and crazing can have a great effect on acid stain and give you a unique looking floor. Staining and sealing is cheaper than ripping it out and redoing it.
Looking the cold joint by the front door I would say you are installing some form of floor covering, that can help a bit.
I've seen cracks in 12" of concrete (Post Tension) they look like hell. you need a qualified crew to do this kind of work, not tract guys.
It looks to me, like water was added to the mix, because things were going slow. As the moisture leaves, the concrete will shrink. More water added, and the more shrinking will happen. The surface being like an eggshell, is the moisture trapped under the sealer, which is a big No-No!!
Not to mention, most all flooring besides stretched in carpet, clearly states, all sealers are to be removed, as they will be the bond breaker for the adhesive. dunbes
Maybe work a rebate or something because that's crap for a new floor!
It does look like they sealed too early...looks like efflorescence under the sealer. Cut too late or not deep enough.
If you want it to look really nice, play with some acid stain. I did this floor in a strip mall that was 4 yrs old, but never occupied. It looked just like yours when we started. Here's some pics of the 'after'
I emphasized the cracks to look like grain in marble...
Yeah, it can be stained... just have to strip the sealer first. I have used xylene to strip a small floor (office and bath....fumes!!!), and for large areas, a citrus based stripper with a floor scrubber.
I just have to ask, with the cracks showing in your pictures opening up, is there any steel in this slab?
I would agree with the above...too much, way too much water/working and too little experience. Looks like something my guys would do, but I don't remember that one.
In my books, that job is unacceptable. Was that floor inspected and signed of by the building department,assuming there are codes and permits required in your area?
Man that is one ugly floor.
i was looking at you pics and you definately have some egg shelling going on. also it kinda looked like you had some popouts. which are caused by internal pressure problums. the pressure thing deals with some of the aggregate absorbing alot of moisture beyond the permissible limit of the material. so your mix could have been a little flawed. you should also look into how the rebar was spaced and what size was used. that could cause some of those big cracks. all in all that really sucks
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Higgins
"The more we sweat in peace, the less we bleed in war."
-- Vijaya Lakshmi Pandit (1900-1990)
a dime till the floor is perfect... id love to see pictures of it ever being perfect... they might be able to seal and cover it up but i would say those crack will for sure come back to haunt you 
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