Under contract On a new construction home in North Texas. Are these cracks normal? Very concerned about these cracks on a new construction foundation. Any advice would be great. Thanks!
Pt slab no issue.
It’s going to depend on exactly where the cracks are and what else (windows, doorways, etc.) will be there, i.e., how the foundation has been prepared to handle those windows and doorways.
If those cracks are in the middle, halfway between the two end points, I don’t have a problem with them. If there foundation has been prepared for doors and windows, and those cracks are equidistant between points, I don’t have a problem with them.
The problem I do have is that you’re in North Texas. I’m from Kingsville, down south of Corpus Christi, and graduated from Texas A&M University. I had a lot of soils and engineering courses, so I’m familiar with most of the soil areas there in north, central, east, and south Texas. Your rainfall and soils could prove to be the main issue, and a weak point in the concrete, even when I believe they are common concrete curing cracks, will be exactly that, a weak point.
Do you have more pictures of that whole side of the house, blueprints, etc.? I could give you a lot more guidance with more information.
The slab was just placed, so rain falls aren’t the cause. Those cracks in a post tensioned slab aren’t likely an issue, but I can’t see the rest of the foundation to be 100% sure.
A visual photographic observation of these cracks indicate concrete shrinkage to me.
Depending upon that assessment over the Internet from a picture does not demonstrate due diligence. Your home inspector should assess things a little bit further.
What would you suggest the inspector if he has one should do further? Curious to folks opinions on this so I can learn as always.
Cracking in post tensioned slabs prior to tensioning the strands/tendons is very common and this situation has a specific name called “Restrained to Shortening” or RTS cracks. From the limited photos, this is what it looks like.
As concrete shrinks during the drying process it would not crack if it were supported by a perfectly smooth frictionless surface, but in reality this is not the case. The ground surface the slab is poured on will restrain the concrete from sliding, which develops stresses in the concrete causing cracks to develop, i.e. RTS cracking. If reinforcing steel or wire mesh were added near the surface ( 1.5” to 2” below the top) it would strengthen the concrete and help resist the dry shrinkage forces that develop, however most post tensioned residential slabs typically do not have any reinforcement other than the post tension cables, which are not designed for dry shrinkage. The good news is these RTS cracks are typically harmless and may partially close up if not too much debris has fallen in these cracks before the cables are tensioned.
Josh, where in North TX are you? If close to Dallas, give Barry Adair a call
Hire him for all the phases (as many as he offers), you won’t regret it!