Originally Posted By: ssopha This post was automatically imported from our archived forum.
JPope,
The building is not on a hill side. There are lookout basement windows on one side of the house. I know it is a controll joint because there are others that are spaced properly and have hairline zig zag cracks. This bigger than usual cracks runs the length of the basement width. There are no water intrusion or upheave that I can visually verify.
Originally Posted By: kmcmahon This post was automatically imported from our archived forum.
I didn’t say it was a controlled crack. Control joints are made so the slab has a place to crack when it shrinks. If it doesn’t have a “control Joint” made for it(zip strip or sawed joint), the tendency is for the slab to makes it’s own in an area of least resistance, commonly at mid span (which this looks like)
Originally Posted By: wpedley This post was automatically imported from our archived forum.
Like Kevin said If it doesn’t have a “control Joint” made for it(zip strip or sawed joint),and this wasn’t installed, then yes the floor will crack at the point of least resistance. Could be a number of reasons from under-tamped soil,improper amount of stone,etc., you just can’t tell. Just report what you see and call for further monitoring.
From what I can see from the pics there doesn't seem to be any
Originally Posted By: jpope This post was automatically imported from our archived forum.
kmcmahon wrote:
I didn't say it was a controlled crack.
I wasn't directing this at you Kevin 
ssopha wrote:
I know it is a controll joint because there are others that are spaced properly and have hairline zig zag cracks.
I'll take your word for it although I looked closely and could not see any indication of control. I've worked with concrete for many years and have no idea what a "zip strip" is and I've never seen a "controlled" crack look so jagged.
A six foot level laid across the crack (perpendicular) could help you determine if there is any heaving. You could (should) check the perimeter footing and wall (where visible) to see if the crack has transferred.
Absent any other related conditions, you may be safe to recommend monitoring rather than evaluation.
-- Jeff Pope
JPI Home Inspection Service
"At JPI, we'll help you look better"
(661) 212-0738
Originally Posted By: kmcmahon This post was automatically imported from our archived forum.
Sorry bout that Jeff, thought you wuz talkin to me!
I probably inspected close to a million cubic yards of concrete while I lived in Houston. Anything that has happend or will happen to concrete, I’ve probably seen it. Zip strips were commonplace down there as well as up here.
Originally Posted By: jpope This post was automatically imported from our archived forum.
Quote:
For information on them go here:
Every thing on that page I've seen except for the "zip strip."
I had the pleasure of "pour watch" during the largest monolithic pour in the history of the State of Hawaii in '93.
23,000 yards, 1 pour, 15 pumps, over 1000 truck loads and three and a half days (12 hours on and 4 off) 
-- Jeff Pope
JPI Home Inspection Service
"At JPI, we'll help you look better"
(661) 212-0738
Originally Posted By: kmcmahon This post was automatically imported from our archived forum.
Now that’s a big one. …my largest was 8500cyd. 16 pumps in 23 hrs. A week later we did the sister building next door at a little over 6,000cyd. Matt foundations are really neat…and my god the rebar!!!I spent 3 weeks inspecting it as they installed it.
Originally Posted By: kmcmahon This post was automatically imported from our archived forum.
Only picture I have left after all these years…must’ve lost the rest but this is at the start of the rebar process…Those are rebar support “chairs”. A little larger than most are probably used to seeing.
…my largest was 8500cyd. 16 pumps in 23 hrs. A week later we did the sister building next door at a little over 6,000cyd. Matt foundations are really neat…and my god the rebar!!!I spent 3 weeks inspecting it as they installed it.