Secondary containment is one of the better jobs in this trade. The specifications are real, the buyer is usually sophisticated, and the consequences of failure are regulatory rather than cosmetic, which means nobody is shopping purely on price. It is also a job where the low bid is wrong more often than in almost any other coatings work, and it is usually wrong in the same three places.
1. The prep line item is where bids go to die
On a containment basin the coating is a small fraction of the total. The work is surface preparation, detail work, and access. A bidder who is meaningfully cheaper than everyone else has almost always thinned the prep, because it is the only line item large enough to matter and the only one the client cannot inspect after the fact.
Concrete containment structures are frequently older than the regulation that now governs them. They have curing compounds, previous coatings, oil saturation, carbonation, spalling, and cracks that have moved. Getting to sound, clean, properly profiled substrate is genuinely expensive, and estimating it from photographs is how contractors lose money.
Walk it. Take a hammer and sound the floor and the walls. Do a few test pulls if you can get permission. If the client will not let you inspect before bidding, price the uncertainty or decline the job — do not absorb it.
2. Details are most of the labor and almost none of the square footage
The square-foot number on a containment job describes the easy part. The difficult part is everything that interrupts the flat surface:
- Wall-to-floor transitions, which need coving and reinforcement and are where hydrostatic and thermal movement concentrate
- Pipe penetrations, each of which is an individual detail and a potential leak path
- Sumps, trenches, and drains
- Expansion and control joints, which must be detailed to accommodate movement rather than simply coated over — a rigid coating bridged across a moving joint will split, and it will split at the worst possible location
- Anchor bolts, equipment pads, ladder mounts, and column bases
- Termination edges at the top of containment walls
Count these individually and price them individually. A basin with forty penetrations and a basin with four have very similar square footage and very different labor. Estimating containment by square foot alone is the second-most-reliable way to lose money on it.
3. Access, confined space, and the schedule the client has not mentioned
Containment structures are often below grade, often inside operating facilities, and often classified as permit-required confined spaces. That brings in atmospheric monitoring, ventilation, attendants, rescue provisions, and a permit process that consumes real hours before anyone sprays anything. Spraying isocyanate-containing material into a confined space also brings ventilation and respiratory protection requirements that are not optional and not cheap.
Then there is the plant schedule. The tank has to be emptied, cleaned, and taken out of service, and that window is frequently short, frequently at night, and frequently moves. If the client wants the asset back in forty-eight hours, that constrains your material choice, your crew size, and your contingency plan, and every one of those has a price.
What to put in the bid that most bidders leave out
- The preparation standard, named. Not “surface will be prepared” — the actual standard and target profile, with the ICRI CSP number or SSPC designation.
- Moisture testing as a line item, with the test method, and a stated hold point if readings exceed the manufacturer’s limit. This protects you when the slab is wetter than anyone expected.
- Thickness verification, wet film during application and dry film after, with the frequency you will document it at.
- Adhesion testing per ASTM D4541 on a stated number of locations, and holiday or spark testing where the lining’s integrity is the point of the job — which in containment, it is.
- A documented exclusion for concrete repair beyond a defined quantity, priced as a unit rate. You will find deteriorated concrete. Decide now who pays for it.
- Your inspection records as a deliverable. On regulated containment the client may need to show a regulator that the lining was installed to spec. Documentation has value to them, and it protects you.
The reframe worth making with the client
The buyer of a containment lining is not really buying a coating. They are buying evidence that the structure will hold what it is supposed to hold, and documentation that they did it correctly. A bid that includes testing, verification, and records is answering the question they actually have, and it is much harder to compare against a cheap bid that does not.
That is also, incidentally, the honest argument for not being the low bidder. You are not selling a thicker coating. You are selling the part where somebody proves it works.
General trade information, not a specification or a legal opinion. Containment requirements vary by jurisdiction, stored product, and applicable regulation — confirm requirements with the governing authority and a qualified engineer.