How to pour decorative concrete in cold weather
Decorative concrete can still be placed effectively in the cold, as long as you follow certain precautions.
Being properly prepared is particularly important when pouring decorative concrete in cold weather. Low temperatures – below 4.4C – can cause curing issues, strength problems and cracking.
Dealing with frozen ground
Avoid placing concrete on frozen ground, snow or ice, which will cool the concrete and slow down setting. This can also cause crusting, with the lower areas of the concrete remaining soft as the upper section sets. A further problem is that when the ground settles as it thaws, the concrete may crack.
The solution is to thaw the ground with construction heaters or electric blankets and remove all ice and snow and any standing water that could get into the concrete. Warm up anything that will come into contact with the concrete, including forms. In less severe cold weather, you can cover everything with tarps the day before the pour.
You should also consider whether you’ll need lighting if the concrete still sets more slowly than anticipated and the sun disappears as you’re ready to begin the finishing process.
How to use curing blankets
Using curing blankets on coloured concrete to prevent freezing can result in a dappled appearance unless you take certain precautions such as placing a barrier of one or two layers of landscape fabric between the concrete and the blanket.
When you remove the blankets, rinse the entire slab surface immediately to reduce white discolouration.
Worker safety in cold weather
Working outside in cold weather for prolonged periods can cause cold stress and hypothermia.
To avoid problems like this, ensure your concrete pouring crew wear three layers of clothing and consume hot, high-calorie food and drinks.