HOW DO I VERIFY
A CONCRETE
CONTRACTOR'S WORK?
You verify concrete work by verifying the record of it, because the variables that decide how a slab performs stop being observable within hours of the pour. That makes this a timing problem rather than an inspection problem, and what you can establish depends almost entirely on which of three windows you are standing in when you ask.
Verification usually means looking at the finished work. Concrete is the trade where that method runs out first.
The mix that was specified, what actually arrived on the truck, the conditions during placement and how the slab was cured are the four things that govern the next 20 years, and all four stop being visible when the concrete sets. So verifying a concrete contractor means verifying that those four were captured while they were still capturable, by the party who made the decisions, and kept. Everything else you can do is real and worth doing, and none of it substitutes for that.
Same question, three very different amounts of leverage.
Find yourself on this list before doing anything else, because the useful advice is different in each case and most published advice quietly assumes the first one.
Before you sign
The most leverage you will ever have, and the least information. You cannot verify work that does not exist yet. What you can verify is whether this contractor produces a record at all, which is the one thing that determines whether windows two and three are worth anything.
What to ask before hiringOn pour day
The only window in which the four governing variables are directly observable. It lasts hours, it happens once, and almost nobody is told it is the important one. Section III is what to do with it.
After the job is finished
The window most people are actually in when they ask this question. Less leverage, but more than people assume, because some of the record is held by third parties who kept it on their own schedule rather than the contractor's.
The reason this ordering matters is that verification advice given for window one is close to useless in window three, and advice for window three sounds defeatist in window one. They are different questions wearing the same words.
The honest limits, stated up front.
This is the part most guidance skips, and skipping it is what leaves people believing they verified something they did not.
It establishes the finish work. Flatness, edge quality, joint layout, consistency of texture, whether the drainage falls the way it should. That is genuine craftsmanship and it is genuinely visible. What it does not reach: two slabs built to entirely different specifications can look identical on the day the forms come off, because the mix and the cure leave no trace the eye can read. Determining what hardened concrete actually is takes a physical sample and a laboratory, under a recognised professional method with its own standard practice, ASTM C856/C856M, Standard Practice for Petrographic Examination of Hardened Concrete. That establishes what the concrete IS. It cannot establish what was specified, what was ordered or what arrived, because those are documents rather than material.
They establish the experience of hiring someone. Whether the crew showed up, cleaned up, communicated and honoured the schedule. Those are real and they are worth checking. What they do not reach: a review written a month after a pour cannot speak to what the slab does in year 5, because the reviewer does not know yet.
They establish that a business met a threshold to operate and carries cover. Check them. They matter, especially the insurance. What they do not reach: a license is not a record of what happened on your job, and it does not follow the crew from pour to pour.
It establishes a fact about your specific pour, made by somebody with no stake in the dispute. The batch ticket is the clearest example: the ready mix producer's own record of what was actually in the truck, produced by a third party, already existing on an ordinary residential pour. This is the category that survives contact with a disagreement three years later.
Six things to capture while they still exist.
If you can be present, this is the highest value hour you will spend on the entire project. None of it requires expertise, none of it requires interfering with the crew, and all of it is ordinary information that a professional operation is already tracking.
Why on the day: the ticket arrives with the truck. Collecting it costs nobody anything at the moment it is in someone's hand, and it becomes an errand the moment it is not. If there are multiple trucks, you want all of them, because they are not guaranteed to be identical loads.
Why it matters: how long material waited before placement is a real variable and it exists only as a memory unless somebody writes it down. How to do it: the timestamps on your own photographs do most of this for you if you take photographs at each stage.
Why it is worth doing even though weather is a public record: the archived station data tells you the region, and your note tells you the site. Both are useful and the second one takes ten seconds. The public version is at the NOAA National Centers for Environmental Information, which publishes archived daily observations by station for free.
Why this is the most perishable item on the list: it is visible for a matter of hours and then it is permanently behind concrete. What to capture: wide shots that establish the whole area, then closer shots. You are not judging it. You are recording that it existed in a particular state on a particular date.
Why now rather than earlier: the plan can change on the day based on conditions, and the version that matters is the one actually used. What to capture: the method, the duration, and who is responsible for it, because on residential work that is sometimes you.
Why it is not obvious: on a job that runs through a builder, a broker or a subcontracted crew, the company you contracted with may not be the party making the calls. What you want is a name, because the contractor of record is the party who owns the pour day decisions and therefore owns the record of them.
That list is a homeowner performing, by hand and in one morning, a rough version of what a documented pour captures as a matter of routine. It is worth doing even in that rough form, and it is a fair description of why a protocol for it exists.
Four things still recoverable once the job is done.
Less leverage than pour day, and more than most people assume, because some of this is held by parties who keep records on their own schedule.
Everything else is retrieved by date. The invoice, the permit file, a bank record, a text thread or a photo timestamp will usually settle it, and without it you are asking people to search their records for a season rather than a day.
The batch ticket can live in two places. If the contractor cannot produce it, the plant that batched the load may hold its own copy, and there is no single national retention period for it. Ask plainly and without accusation, because it is a routine document and framing it as a challenge is what makes the conversation go badly.
How long a plant keeps it depends on where you are, and in at least one state there is a number. NRMCA's own Quality Certification criteria leave the period to the producer, defined in company policy by the type of information and the type of project. Some jurisdictions set a figure instead. In California every load of ready mixed concrete arrives with a weighmaster certificate, which is what the concrete ticket is, and state law requires the weighmaster to keep true copies of all certificates issued for four years. Sources: NRMCA Quality Certification, Ready Mixed Concrete Quality Management System, Certification Criteria, Version 2, 2016, section 5.6.2. California Department of Transportation, Reinforced Concrete Construction Manual, Chapter 5, June 2025. California Business and Professions Code Section 12716.
This is the one governing variable that was never in anyone's private custody. NOAA's National Centers for Environmental Information publish free access to archived daily measurements of temperature, precipitation and wind, searchable by station and by date.
Photograph from a fixed position, dated, with something in frame for scale, and repeat in 90 days. Whether something is stable or progressing is the question every professional and every warranty conversation turns on, and it is a question only a dated series answers.
We score the record. We do not grade the concrete.
This page would be worth less if it ended by telling you the answer is us. So here is exactly what PSIP is and what it is not, in the same terms as everything above.
- ×PSIP does not inspect anybody's work. PSSG does not supervise, direct, inspect, or perform the contractor's concrete work. What PSIP scores is the completeness of the record a contractor produces, which is a different activity from inspection and should not be confused with it.
- ×PSIP does not say a certified contractor does better work. A PSIP certified contractor has committed to documenting the pour and to retaining the record. That is a statement about their paperwork, not a judgment of their concrete, and treating it as the second thing would make it worth nothing.
- ×PSIP does not rank contractors. Records are sorted, never ranked. Sorting is an order you choose and can reverse. Ranking is a judgment made on your behalf, and a body that scores documentation has no basis for making it.
- ×A record is not a warranty. Certification is a documentation and scoring credential. It is not a warranty, guarantee, or insurance of the contractor's work; not engineering or design services; and not a government license or code approval. PSSG is not a party to any contract between the contractor and the customer. The contractor is solely responsible for its own work, methods, safety, code compliance, licensing, and customer relationships. A closeout packet establishes what was specified and what was delivered, which is the factual ground a warranty or a claim would be argued from.
Every list on this page works on a contractor who has never heard of PSIP, and that is deliberate. If you use them and never think about certification again, the page did its job.
Asked and answered.
You verify the record of it, because the four things that govern how a slab performs, meaning the mix that was specified, what actually arrived on the truck, the conditions during placement and how it was cured, all stop being observable within hours of the pour. What you can establish depends on whether you are asking before you sign, on the day of the pour, or after the job is finished, and the pour day is the only window in which those variables are directly observable.
Not reliably. A finished surface establishes the finish work, meaning flatness, edge quality, joint layout and drainage, and that is real craftsmanship that is genuinely visible. Two slabs built to entirely different specifications can look identical on the day the forms come off, because the mix and the cure leave no trace the eye can read. Determining what the hardened concrete actually is takes a physical sample and a laboratory, under a recognised standard practice, ASTM C856/C856M. That establishes what the concrete is. It cannot establish what was specified, ordered or delivered, because those are documents rather than material.
It depends which window you are in, and the answer is most favourable on pour day. An inspector present during placement can observe the variables while they exist. An inspector arriving after the work is finished is working from the finished surface and whatever record exists, with more experience reading both. Establishing what the hardened concrete actually is moves past looking, into sampling and laboratory work. If you are choosing where to spend, spending it on the day the concrete is placed buys more than spending it afterwards.
A specific artifact rather than an assurance. A closeout packet covering what was specified, what arrived, the conditions on the day and the cure, signed at completion. The useful version of this question is asked before the work starts, because you can ask to see the format a contractor uses and decide then.
It is the one piece of paper on a residential pour that already exists, is already produced by a third party, and is not something the ordinary residential process puts in the owner's hands. It is the ready mix producer's record of what was actually in the truck, which makes it the difference between what was ordered and what arrived. Keeping it costs nobody anything, and it is the category of evidence that survives contact with a disagreement years later.
No, and more is recoverable than most people assume. Fix the exact pour date first because everything else is retrieved by date. Ask the contractor for the batch ticket and then ask the plant that batched the load, since it keeps its own copy on its own retention schedule. Pull the archived weather for the pour date, which is a free public record. Then start a dated photo series on anything you are watching.
They establish the experience of hiring someone, meaning whether the crew showed up, cleaned up, communicated and honoured the schedule. Those are worth checking. What they cannot reach is what the concrete does later, because a review written a month after a pour cannot speak to year 5. Concrete failure in residential work often surfaces years after the last review was written.
It is the party who owned the decisions on pour day and therefore owns the record of them. It matters because on a job that runs through a builder, a broker or a subcontracted crew, the company you contracted with may not be the party making the calls while the concrete is going in. What you want is a name, established before the pour if possible and reconstructed afterwards if not.
Every term on this page is defined once.
Documented pour, closeout packet, batch ticket, contractor of record and point of pour each have a single standalone definition in the PSIP dictionary, with the primary sources behind them.