In the world of rendering and construction, small additives can make a significant difference to the performance and durability of materials. One such additive is calcium chloride flakes. Known for their ability to enhance curing speed, improve workability, and increase adhesion, calcium chloride flakes have become a staple in the rendering industry, especially for projects in colder climates or where time constraints are crucial. In this post, we’ll explore what calcium chloride flakes are, how they work, and how to use them safely in your render mix.
Calcium chloride flakes are a type of inorganic salt, made up of calcium and chlorine. When added to water, they dissolve readily, releasing heat and accelerating the setting process of various building materials. Compared to other salts or chemical additives, calcium chloride is particularly effective for construction because it enhances curing time without compromising the strength of the final product. In rendering, it’s used in small amounts to ensure that render cures faster and adheres better to surfaces.
Calcium chloride flakes are especially useful in colder weather, where traditional render mixes may take too long to set. By speeding up the curing time, these flakes allow render to dry and harden quicker, preventing damage from potential freeze-thaw cycles.
Calcium chloride doesn’t just speed up curing; it also improves the workability of the mix, making it easier to apply and shape on surfaces. This added flexibility can be particularly helpful for achieving smooth, even finishes.
Render with calcium chloride flakes has better bonding properties, ensuring it adheres more securely to the underlying surface. This increased adhesion reduces the likelihood of cracking or detachment over time, especially important in demanding environments or on older surfaces.
While calcium chloride offers these distinct benefits, it’s important to note that it should be used in recommended amounts to avoid any adverse effects.
Using calcium chloride flakes is straightforward, but it’s essential to follow a few steps to ensure the best results:
Measure the Calcium Chloride Flakes
Use a measuring scale to add the right amount of calcium chloride, typically around 1-2% of the cement content in the mix. Avoid going above this amount, as too much calcium chloride can negatively affect the render.
Dissolve the Flakes in Water
Before adding calcium chloride flakes to the render mix, dissolve them in warm water. This step ensures an even distribution throughout the render, preventing any clumping.
Add the Solution to the Render Mix
Once dissolved, add the calcium chloride solution to the render mix and blend thoroughly. Ensure the solution is evenly mixed to allow the entire render batch to benefit from accelerated curing and improved adhesion.
Midrender Safety Tips: Wear gloves and avoid direct contact with calcium chloride, as it can irritate the skin. Store any unused flakes in a dry, airtight container, as they can absorb moisture from the air and degrade over time.
While calcium chloride is generally beneficial in rendering, there are a few potential issues to keep in mind:
In cases where calcium chloride might not be suitable, there are alternatives available. Some contractors opt for non-chloride accelerators, which provide similar curing benefits without the risk of metal corrosion. Synthetic accelerators or other salt-free additives can also be effective, though they may come at a higher cost. These options are worth considering if working near metal fixtures or if precise colour consistency is a priority.
Calcium chloride flakes are a valuable additive for rendering, offering enhanced curing speed, improved workability, and better adhesion—all of which contribute to a longer-lasting, more resilient finish. By using calcium chloride safely and in the right proportions, you can achieve optimal results without compromising the quality of the render. However, remember to follow best practices in handling and mixing, and consider alternatives when specific project requirements or conditions call for them. With careful use, calcium chloride can be a powerful tool in delivering high-quality render work that stands the test of time.
Calcium chloride flakes are used in rendering to speed up curing times, especially in cold conditions. They also improve workability and enhance adhesion, helping the render bond better to surfaces.
A typical recommendation is 1-2% of the cement content in your render mix. Exceeding this amount may lead to surface discoloration or other issues, so it’s important to stick to recommended proportions.
Yes, calcium chloride can corrode metal if it comes in direct contact. It’s best to avoid using it near exposed metal parts or use protective measures if necessary.
Yes, there are non-chloride accelerators and synthetic additives that can speed up curing without the risk of metal corrosion. These alternatives may be more suitable in certain situations.
If used in excessive amounts, calcium chloride flakes can sometimes cause minor discoloration. Keeping within recommended amounts will generally prevent any impact on the appearance.
Yes, but it’s essential to wear gloves and avoid skin contact, as calcium chloride can be irritating. Store unused flakes in a dry, airtight container to maintain their effectiveness.
