Poured a slab in Edmonton last summer and it spiderwebbed overnight

I was finishing a driveway in Edmonton around 2am during a night shift and the temp dropped faster than I expected. Woke up to a massive crack running through the whole pour because I didn't cover it soon enough. Anyone else had a cold snap ruin a job and what do you do to prevent it?

2 comments

2 Comments

the_gray7d ago

Yeah that Edmonton weather is brutal, Ive lost pours too because you think it's fine at midnight and then by 3am it's already too late. The worst part is when you wake up and see that crack you just know you're going to be grinding and patching for days. Did you use any kind of accelerant in the mix or was it just straight concrete? I've found that even a little calcium chloride can buy you a couple hours but you have to watch it close or it'll set too hot. What's your go to for timing the pour with the forecast, do you check a specific weather app or just go by gut?

morganhayes7d ago

Nah, I don't mess with accelerants. That stuff can backfire hard and leave you with a brittle pour. I just check the hourly wind chill and call it if it's dropping below 5°C within six hours of the pour.