Hello and an advanced “thank you” for all your expertise.
We are building a new home in northern
Florida and inspected our slab just hours after the pour (see pics). A few days passed and more cracks appeared. As we are definitely NOT experts on this subject, should we be concerned about all the cracks? The foreman said to not be concerned as the cracks were not near supporting parts of the structure. We are also wondering about future problems like moisture from the ground and possibly termites.
I’m only allowed to post one photo as a new user, but have 6-7 showing cracks. The worst is inserted here.
You are unlikely to get any significant replies to a complicated subject with many scenarios, so here is some basic info for you to begin your Google Search for targeted information from various concrete industry experts…
Note: The following Link is NOT an endorsement for any company. It is simply some basic info to ponder…
I suspect in Florida the weather was too hot to pour concrete in the first place and the contractor added water to the mix to speed up the finishing.
Plastic shrinkage - Caused by the loss of water by evaporation from the surface of newly laid concrete or by suction of dry concrete underneath . At the surface, plastic shrinkage occurs when the rate of evaporation exceeds the rate of bleeding.
The foreman may be correct, but that is a lot of cracking for green concrete. You should get an arms-length opinion. Maybe even a structural engineer’s assessment.
Post tension cable slab cracks?
Cracks more often occur during curing because the concrete generates heat and expands during the chemical process and shrinks as it cools. Because there is not yet tension on the tendon cables there is no reinforcement to hold the foundation together and cracks often occur during this period of time.
So the slab that was cracking the day it was poured seems to have expanded and it now appears water is coming up from the ground and even perhaps some insects. See pictures and thank you for your continued expert advice!
The effect of high ambient temperatures and high temperature concrete component materials have on the setting time of concrete mixtures is a topic of concern due to the reduced time in which concrete must be placed, consolidated and finished; increased potential for plastic shrinkage cracking, thermal cracking and cold joints; potential strength reduction due to high water demand and high curing temperatures; difficulty in controlling air content; and increased urgency for applying appropriate curing method at an early age.
Daniel, unfortunately your options on making the contractor do anything will be limited to the amount of money you still owe him. Once the contractor is paid in full your leverage is gone.
