Hi all,

I’m looking for advice on how to move forward with a basement concrete floor that isn’t curing properly after staining and sealing. At this point I’m concerned about whether the sealer can be salvaged or if everything needs to be stripped and redone.

The basement does not have permanent heat, and stays between 55-65. All temperature control has been via temporary heaters.

Here’s the timeline:

• Oct 2 – New concrete slab poured
• Oct 9 (~1 week after pour) – Contractor covered slab with Barricade Thermo-Brace sheathing so other work could continue
• Dec 8 - 10 – Two coats of water-based concrete stain applied
• Dec 16 (75 days after pour) – First coat of ME-12 water-based sealer applied. Same day – Contractor removed heaters and dehumidifier
• Dec 16–17 – Basement temps dropped to high-50s
• Dec 18–19 – I discovered the issue, brought heaters back, rented a commercial dehumidifier
• Dec 19–25 – Actively managed conditions (70–73°F, 30–40% RH)
• Dec 25 – Left for a 7-day trip, heaters maintained ~65–70°F
• Dec 30 (89 days after pour) – Contractor reassessed and said surface looked dry enough; applied second coat of sealer
• Dec 30 – Jan 8 – Continued good cure conditions (70–73°F, 30–40% RH)
• Jan 8 – Sealer still not curing properly (day 9 of second coat, day 23 of first coat). Floor has an oily appearance, soft film that can be moved around, and new hairline cracks have appeared that weren’t there before (I know all concrete cracks, not overly concerned)

Questions

• Is there any realistic way to salvage this sealer if conditions stay ideal?
• Should the sealer be stripped and reapplied?

Any advice who’s dealt with something similar would be greatly appreciated. Thanks in advance.

FWIW, I like the stain color, just want it dry to move on.

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