Curing Compound Standards: ASTM, ACI, VOC and DOT
ASTM C309 is the standard for liquid membrane-forming curing compounds. ASTM C1315 covers compounds that also seal, with tougher limits. These pages summarize the standards, VOC rules and agency specs you will see on submittals.
Guides in this section
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ASTM C309
Types 1, 1-D and 2, Class A and B, and the water-loss test.
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ASTM C1315
The cure and seal standard, and how it differs from C309.
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ACI 308
What ACI PRC-308-26 and SPEC-308.1-23 say about curing method and duration.
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VOC limits
Look up the VOC limit for your state, air district or country.
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State DOT requirements
How DOTs specify and approve curing compounds.
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CSA A23.1 curing
Basic and additional curing under the Canadian standard.
Which standard covers what
| Standard | What it covers | Where you see it | Plain-English guide |
|---|---|---|---|
| ASTM C309 | Liquid membrane-forming curing compounds: types, classes and a water-loss limit | Most curing compound labels and specs | ASTM C309 explained |
| ASTM C1315 | Compounds that cure and seal, with a stricter water-loss limit and UV, alkali, acid and bond tests | Cure and seal products, decorative and colored floors | ASTM C1315 explained |
| ACI 308 | Guidance on how and how long to cure concrete | Project specs and engineer notes | ACI 308 summarized |
| VOC rules | Limits on solvent content: 350 g/L federally, lower in some air districts | Product data sheets and labels | VOC limits by region |
| State DOT specs | Agency rules and approved product lists for public work | Highway, bridge and municipal jobs | DOT requirements |
| CSA A23.1 | Canadian curing requirements, including basic curing time | Canadian projects | CSA A23.1 curing |
C309 or C1315?
C309 says a product cures: it holds water in well enough to pass the test. C1315 says it also seals and has passed tougher tests for water loss, UV, alkali and acid resistance, plus a bond test. That bond test uses one tile adhesive only, so passing C1315 does not mean every flooring adhesive will stick. Test before flooring goes down. The curing compound vs cure and seal guide covers the practical difference.
Reading a submittal
- Check the standard and the type and class. "Meets C309" alone does not say whether it is clear, dyed or white, or wax or resin.
- Check the VOC figure against the limit where the job is, not just the federal number.
- For slabs that will get flooring, look for a letter of compatibility from the compound maker, and plan a bond test anyway.
- For public work, confirm the product is on the agency's approved list.
The specifier checklist puts these checks on one page.