When you work in a garden, sometimes you need to do concrete work.
You might build stairs or retaining walls, make a pathway, stack blocks to make a wall, or fix the base of a column. But usually, we avoid doing concrete work in winter. Why?
What is concrete?
It is a mix of cement, sand, and gravel.
This mixture is combined to make a stone-like material. The ratio of cement, sand, and gravel changes depending on its use. For example, smooth finishing concrete does not include gravel.
To make this mixture hard like stone, it needs two things: water and air. Without them, cement, sand, and gravel cannot stick together.
Air is everywhere, so the main thing is water. Mix it well with water, and the concrete is ready to harden.
But in cold weather, the water freezes. When water freezes, it expands. If concrete hardens with frozen water, then thaws later, it cannot become strong. It may even crack.
Also, in cold weather, concrete takes much longer to harden. Concrete that hardens in 1–2 hours in summer can take many days in winter. That is why we avoid winter for concrete work.
There is fast-setting cement that hardens concrete quickly. But it is expensive and still tricky to use. You need to keep it warm while it hardens, and it still takes more time. So avoiding winter is better—both for cost and for good results.
A month ago, a client asked us to fix some cement joints on a retaining wall. It was urgent, but the wall was not in danger of collapsing. Since spring was coming soon, we suggested waiting a little. Now the weather is warmer, and it’s a good time to start the work.