Excess slab moisture can cause debonding and coating deterioration, but other causes (surface prep, application conditions, outgassing) produce similar symptoms. Fixing it means confirming that moisture is actually the cause, then choosing a remediation path that matches how much moisture is present and how the existing coating failed. This guide is written for facility managers, property managers, general contractors, and building owners who are looking at a failed or failing coated floor and need to understand what questions to ask before hiring a contractor.
Visual symptoms suggest moisture, but they do not confirm it. A proper investigation separates moisture-related failure from other causes, such as poor surface preparation, coating applied too thick, or application during unfavorable slab or ambient temperature conditions.
Testing methodology itself — including which method applies to a given situation and how results are interpreted — is covered in Concrete Moisture Testing Methods Compared. Ask the contractor which method they plan to use and why, and have them put the answer in writing before demolition begins.
Once moisture is confirmed as a cause, the remediation path depends on how much moisture and alkalinity the slab is showing relative to what a new coating or primer system is rated to handle, and on the cause confirmed during investigation.
Any remediation starts with removing the failed coating and preparing the slab surface so a new system can bond. This includes profiling the concrete and addressing contamination or residue left behind by the old coating. Colorado Concrete Surface Preparation contractors handle this stage, which should be scoped and priced separately from the new coating itself; see Concrete Surface Preparation Cost in Colorado for how that is broken out.
See Moisture Mitigation for Colorado Slabs for how mitigation products are rated and specified against slab conditions. Moisture-mitigation ratings are product-specific and should never be treated as interchangeable between brands. Tnemec's Series 208 data sheet says hydrostatic pressure, ASR, and migration of oils, chemicals, and other contaminants can adversely affect performance, and Sherwin-Williams' Resuprime MVB data sheet requires a functioning vapor barrier.
Once the slab is prepared and any mitigation product is applied, Colorado Commercial Epoxy Flooring contractors can install the finish system. Use the cost calculator to get a sense of installed cost by service and city before comparing bids.
Preventing a second failure means treating the data sheet for the specific product as setting that product's limits. Confirm slab age, moisture, and pH against the specific primer or coating being installed, not against figures from a different product. For a new installation or a slab being brought up from bare concrete, full mitigation specification is a separate exercise, detailed in Moisture Mitigation for Colorado Slabs.
A proper investigation tests the exposed slab once the failed coating is removed and compares results against the original product's data sheet tolerances. Manufacturer data sheets tie some blistering or pinholing to application conditions (Tnemec 208: outgassing potential increases with higher film thickness; Tnemec 281: avoid applying while temperatures are rising), so the contractor should rule those out rather than assume moisture by default. Ask for the test results and the reasoning in writing before remediation work begins.
No, because the slab underneath needs to be exposed, tested, and properly profiled before a new system can bond. Surface preparation contractors handle this removal and profiling step before any new coating goes down.
No. Each manufacturer publishes its own moisture limits (RH and/or vapor emission rate, and in some cases pH), tied to film thickness and minimum slab age for that product. A primer rated for one threshold should not be assumed to perform the same as a different manufacturer's product rated for a different threshold.
Yes. Concrete pH testing is a separate check from moisture testing, and at least one manufacturer recommends testing prepared concrete with distilled water and pH paper to confirm the surface is sound before coating. Sherwin-Williams says that if the tested pH is 10 or lower, additional preparation is required for a good bond.
The product's data sheet sets the tolerances, so ask the contractor to show the test results next to those limits in writing before the new system goes down.
How moisture mitigation systems work on slab-on-grade concrete, when a coating project needs one, and what to put in the written scope.
How concrete moisture is tested: in-situ RH probes, calcium chloride, and plastic sheet tests, what each reports, and when results are meaningful.
When a new commercial coating can go over an existing one: adhesion testing, scuff-and-recoat, removal, compatibility, and contamination checks.
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