How long does it take for an asphalt cold patch to harden? Up to 6 hours 12% 6 - 12 hours 25% 12 - 24 hours 12% 36 - 48 hours 25% Not sure 25% Get Free Quotes Today! Question: How long does it take for an asphalt cold patch to harden? Top Answer (25% of 8 votes): 36 - 48 hours. Answer: Up to 6 hours Explanation: It will start to harden when tamped Denton's sealcoating Answer: Not sure Explanation: I will be very different with different products. CPR Asphalt Maintenance Answer: 36 - 48 hours Explanation: Cold patch takes 36 hours to harden A & J's Sealcoating Get Free Quotes Today! Find Local Pros Free Asphalt Paving Repair Cost Estimates Related Questions How Long Should Asphalt Cold Patch Last?Top answer: 2-4 years Can You Patch Asphalt in the Rain?Top answer: Yes Can Asphalt Be Patched with Concrete?Top answer: No What are Alligator Cracks? When is the best time of year to repair asphalt?Top answer: Summer