Applying Render Systems in Cold Weather: A Guide for Winter Success

Applying external render products in winter can be challenging. In the United Kingdom, colder months bring harsh conditions—persistent humidity, temperatures below 5°C, and frequent sub-zero days—that can impact the application and performance of renders.

Preparation: The First Step to Success

Preparation is crucial for successful application in cold weather. Store ecorend thin-coat renders, primers, and paints in a frost-free environment, elevated off the ground. For Silicone and Acrylic wet-mix renders, avoid leaving scaffolding or materials out overnight. Instead, set up and prepare the site just before application to shield materials from the elements. ecorend bagged products like monocouche and base coats, however, are designed to withstand outdoor storage all year, remaining unaffected by weather.

Managing Drying and Avoiding Aesthetic Issues

Cold weather can disrupt drying rates, leading to uneven finishes in areas exposed to varying sun and shade levels. Powder products, such as ecorend MR1 Monocouche One Coat Render, can develop shadow lines from scaffolding where shaded sections dry slower. To achieve a consistent finish, cover the exterior surface to manage drying rates evenly and avoid color variations.

Allowing for Extended Curing in Cold, Damp Conditions

In winter, damp, cold conditions can prolong drying and curing times for all render products. Substrates exposed to the elements for extended periods, particularly on north-facing walls, can retain moisture for weeks, slowing the curing process further. Be prepared to allow extra time for curing in cold weather.

Key Considerations for Base Coats, Monocouche, and Mineral Thin Coat Renders

Render products that rely on water for binder hydration require temperatures above +5°C and humidity below 85%. Winter conditions mean slower water evaporation, which affects the product’s absorption into the substrate. Before applying render, ensure that substrates are not frozen, and avoid application if frost is expected within 24 hours. For Monocouche renders, maintain a minimum temperature of +5°C throughout application.

Accelerating Curing with QS1 Quick Set Accelerator

To counter the effects of cold weather, ecorend’s QS1 Quick Set Monocouche Accelerator can expedite scraping times, even at +5°C. By replacing a portion of the gauging water, this accelerator helps reduce curing time to summer-like speeds. However, keep in mind that it is not an antifreeze, so ensure uniform scraping around the structure to maintain consistent color.

Silicone & Acrylic Thin Coat Render Systems

Silicone and Acrylic renders need temperatures above +5°C and humidity below 85% for at least 48 hours post-application to cure properly. Confirm that base and primer coats are fully cured before applying the topcoat, as winter's trapped moisture and limited UV exposure can lead to wash-off and curing delays.

The SR365 Ultimate Silicone Thin Coat Render: Designed for Winter

Unlike standard thin coat and monocouche renders, the European-patented SR365 Ultimate Silicone Thin Coat Render is ideal for variable weather conditions, performing reliably in temperatures from -5°C to +25°C. With BBA certification, it withstands up to 99% humidity and becomes rainproof within two hours at temperatures above +5°C, offering enhanced durability and flexibility across seasons.

Final Tips for Winter Render Success

With the right preparation and attention to environmental conditions, you can achieve excellent render results even in winter. For specific product guidance or additional support, reach out to our Technical Team to ensure that your winter render projects are completed to the highest standard.