Does your floor have cracks?

[buening]

I think where a lot of people go wrong is they find the cheapest contractor available that works out of his house instead of ponying up the extra bones and hiring a professional concrete contractor that is an actual business and has their own building. Getting someone that has poured slabs for warehouses and industrial buildings will cost more (and may have to wait longer till they have a slow period), but a crack free headache free slab is worth it IMO. These guys have their own mix designs and know exactly what is needed for subbase preparation and curing methods. A standard 5 bag mix may not cut it depending on the weather and site conditions, but a common contractor would not know the difference. Merely my 0.02

 

[Al Bundy]

I totally disagree with the statement that concrete will crack.

Thank you for making that statement. I've been in a discussion on another thread about this very topic and the consensus there seems to be that cracking is normal. My view is that's a cop out that typical builders/contractors use to cover for their shoddy work. I'm not saying it can't happen or that it doesn't require extensive prep work, but I hired a guy with 25+ years experience that does nothing but concrete. I did the prep work but he inspected and approved it. My floor is not cracked. No it was not cheap, but I got what I paid for. Furthermore I could show you the floor in the garage of my dad's house that is almost 50 years old that is not cracked.

 

[TheGunCollector]

Yes. Both upstairs and downstairs concrete floors of my garage have cracks, as well as my driveway. Many are along the expansion joints, but there are a bunch of smaller, spider thin cracks.

 

[jrhaines2]

I totally disagree with the statement that concrete will crack. Over a very long term I suppose it is inevitable but in the lifespan of a typical garage no. Unless there are circumstances that cannot be controlled there is no reason why concrete must crack. If your contractor tells you that your concrete MUST crack, find a better concrete guy.

For our resident project manage, I am sure in large scale pours there are issues that are assumed but in a small scale foot print of the average garage, the possibilities can be minimized.

If it was not for extending the concrete over my foam at the service door (about 1" thick), I would have NO cracks at all. That one crack is minimal and barely noticable.

I would not expect any contractor to gaurantee no cracks but a good one can do it most of the time on small scale jobs.

Most of the replies in this thread state that their concrete has cracks and you disagree with the statement that concrete will cracks.

Why would you not expect any contractor to guantee no cracks?

Would you expect any roofing contractor to not guantee a leaking roof?

 

[jrhaines2]

+1! There are many jobs where the Contractor has to guarantee no cracks (larger warehouses). You won't find many that will guarantee a small slab though due to the small profit margin. A good quality concrete contractor can provide a small slab like a garage that will not crack.

A good quality contractor can prove a slab that does not crack every time,true of false?

 

[buening]

False, mistakes do happen and on these small jobs there are variables that are sometimes out of the Contractors control, like montmorillonite clay soils or if the client insists that the slab gets done ASAP and it's 100° outside.

With that said, on larger jobs the Contractor HAS to guarantee no cracks, as it is in writing in their contract. Some of these same jobs also specify NO control joints either, which are commonly spec'd in Budweiser distributor warehouses and freezer warehouses. Many of these are poured in controlled environment (temp/humidity), which helps a ton. They also have soils reports, etc to eliminate the unknowns that can occur on a small garage. I've said it over and over, subgrade prep, proper mix design for the temp/humidity/site conditions, proper amount of rebar for temp/shrinkage control, proper finishing, and proper curing (KEY!) are what a quality contractor needs to know to provide a slab you'd be happy with. If you think it's good enough that your freshly poured slab has crazing and shrinkage cracks, then you need to raise your standards a bit. Too many backyard "pro" concrete guys have made this mindset common unfortunately.