The Ultimate Guide to Winter Working

Winter working is certainly one of the construction industry’s biggest challenges. Rain, wind, and freezing temperatures can scupper work timeframes, especially in the insulation and rendering industry. However, there are many strategies you can employ to combat the elements. With help from the experts at EWI Pro, we’ve compiled the ultimate guide to winter working to get your project finished in time and to the highest quality.

1. Scaffolding protection

Scaffolding is an integral part of the insulation and rendering process. The process of installation naturally starts from the bottom. For a two-storey building, you’ll require scaffolding to safely access the rest of the building. The scaffolding will also act as a shell around the whole building; however, without the proper shielding, it will not keep out any of the elements and debris that come with winter work. Therefore, it’s imperative to install certain measures to your scaffolding to protect your basecoat and render stages and allow them to dry and cure properly.

Debris netting for winter working

Debris netting is a durable, flexible mesh material draped over scaffolding to contain loose debris, dust, and tools and prevent them from falling to the ground or neighbouring areas. It is commonly made from polyethene or other high-density materials that resist tearing and withstand varying weather conditions.

Benefits

1. Enhanced Safety: Debris netting reduces the risk of injury to workers and the public from falling objects by containing debris and small objects.
2. Dust Control: Netting helps limit dust dispersal, especially in urban areas where construction dust could impact air quality.
3. Weather Protection: Certain types of netting can also serve as a wind or rain barrier, creating a safer working environment for construction teams.
4. Privacy and Security: Debris netting also provides some privacy for construction projects and deters unauthorised access.

Types of Debris Netting

• Standard Netting: Often used for general debris containment, this type is suitable for smaller-scale projects with minimal debris.
• Flame-Retardant Netting: Used on sites where fire hazards are a concern, this netting is treated to resist flames, improving site safety.
• UV-Stabilised Netting: This netting is designed to withstand long-term sun exposure without degrading, which is ideal for projects that require extended use.

Mono flex cover

Mono flex is a robust, weather-resistant scaffold sheeting made from reinforced polyethene. It’s known for its strength and durability, thanks to a multi-layered structure that includes strong polyester grids within the plastic. These grids enhance tear resistance, even in high wind conditions, making them ideal for large-scale or long-term projects.

Benefits

1. Weather Protection: Mono flex sheeting forms an effective barrier against wind, rain, and snow, allowing work to continue even in adverse weather. This protection can also prevent water ingress, helping safeguard partially completed structures and materials.
2. Containment: Mono flex keeps dust, debris, and materials from escaping the construction site, minimising the risk of injury to people below and containing pollutants to comply with environmental regulations.
3. Thermal Regulation: Certain mono flex covers offer insulating properties, which can help maintain a more controlled environment within the scaffold. This is useful for projects involving temperature-sensitive materials or processes.
4. UV Stability and Fire Resistance: UV-treated mono flex can withstand long-term sun exposure without degrading, and many types are fire-retardant, essential for safety on high-risk sites.

2. Water management

Water management is crucial during the retrofitting stage, as pipes and gutters will often be moved and replaced. Effective treatment of these areas is imperative to the drying and curing of various materials. Ineffective water management can also lead to water leaking behind the insulation and travelling into the property.

Temporary fall/downpipes are flexible or semi-rigid drainage systems that attach to scaffolding or building structures. They are typically made of durable, weather-resistant materials like PVC or high-density polyethene (HDPE) and can be quickly installed and removed as needed. They often come in modular sections, allowing for easy length adjustments depending on the project’s height and specific needs. Temporary downpipes are usually installed at roof edges or scaffold platforms to catch and channel water downwards. They can be secured with adjustable clamps or ties, and sections are joined with flexible connectors to create a sealed, continuous system. The water is then directed to a designated drainage area or stormwater system.

Benefits of downpipes for winter working

1. Controlled Water Management: These pipes direct water from the construction site, reducing the risk of flooding or water damage to scaffolding, materials, and partially completed structures.
2. Site Safety: Temporary down pipes manage water runoff, keeping walkways, entry points, and work areas dry and minimising the risk of slips and falls.
3. Protection of Building Facades: Redirecting water helps prevent excessive moisture from reaching walls and other structures, which can lead to staining, material damage, and mould growth.
4. Environmental Compliance: Temporary drainage systems can help ensure water runoff complies with environmental regulations, particularly on sites with sensitive ground areas.

3. Freshly laid basecoat care

A freshly laid basecoat needs to dry and cure. If the moisture freezes in colder temperatures, the basecoat can fail. A hessian covering is an effective way of protecting the basecoat overnight.

Hessian covering to protect basecoat during winter working

Hessian (or burlap) covering is popular due to its breathability, insulation, and protective properties.

Benefits

1. Moisture Retention: Hessian helps retain moisture within the basecoat, slowing drying. This controlled drying is especially beneficial in warm or windy conditions, preventing the basecoat from drying too quickly, which can lead to cracking or shrinking.
2. Protection from Freezing: In cold weather, the basecoat can be susceptible to freezing, which weakens its structure. Hessian provides a layer of insulation that helps protect the basecoat from sudden temperature drops.
3. Breathability: Unlike plastic sheeting, hessian allows moisture to escape gradually, preventing condensation build-up while offering a shield from direct sunlight, wind, and rain.
4. Flexibility and Reusability: Hessian sheets are durable and can be reused across different project stages, making them a cost-effective option.

4. Drying techniques

With lower temperatures come extended drying times. Humidity will also play a part in this process. However, as a rule, moisture will naturally evaporate much slower at lower temperatures. This can significantly impact your project timeline. There are techniques you can employ for drying during your winter working.

Blow heaters for better winter working

Both direct and indirect blow heaters can be invaluable on construction sites during cold weather to accelerate drying times for materials like plaster, render, and basecoats. Proper drying is essential to avoid issues like cracking, delamination, or weakened structural integrity

Direct blow heaters

These heaters combust fuel (like propane or diesel) and blow the heated air directly into the space. While they produce a high volume of warm air, they also emit moisture and combustion by-products such as CO₂ and some fumes. This method is highly effective in large, well-ventilated areas or outdoors where air circulation can disperse emissions.

Indirect fire heaters

These heaters separate the combustion process from the airflow, typically using a heat exchanger. Clean, dry, warm air is blown into the space, while combustion by-products are vented outside. This makes indirect heaters ideal for enclosed or sensitive work areas where the air needs to be clean and dry.

To employ these heaters effectively, you’ll also need to consider the positioning, ventilation, temperature control, and monitor humidity on site. Place the heater strategically to cover the entire surface area evenly. For direct heaters, position them to avoid directly blowing on fresh materials, as excessive heat may cause cracking. If using direct heaters, ensure adequate ventilation to disperse moisture and fumes. Maintain a consistent, moderate temperature. Excessive heat can cause the surface to dry too quickly while leaving inner layers damp. For materials that require low humidity to set, such as plaster, an indirect heater is best to avoid introducing additional moisture.

Completion timing

Timing is imperative to the successful protection of your basecoat. To allow for the initial set of most basecoats, you’ll need to finish by 1 p.m. If you work late into the afternoon, temperatures drop quickly, and the basecoat may not be set properly.

5. Storage conditions

Proper storage of materials on construction sites is crucial to maintaining their quality and ensuring optimal application.

Pasty Products

• Storage Location: Indoors, ideally in a dry, enclosed area to protect from external elements.
• Temperature: Maintain an ambient temperature of at least +10°C. This minimum temperature prevents the pasty products from becoming too thick, difficult to apply, or even freezing in very cold weather.
• Additional Tip: If storing for extended periods, avoid areas with direct sunlight or fluctuating temperatures to prevent changes in consistency.

Powder Products

• Storage Location: Also stored indoors to prevent exposure to moisture, as powder products can easily absorb humidity from the air, affecting their performance.
• Humidity Control: Choose a storage area with low humidity to avoid clumping or premature setting.
• Packaging Integrity: Ensure bags or containers remain sealed until ready for use. To minimise contact with dampness, avoid placing powder products directly on the ground; consider using pallets for storage.

6. Mixing and application

Following the right mixing and application practices is essential to ensuring that basecoats and topcoats cure properly in colder conditions. While our Silicone Render comes ready to use, we insist that it be mixed for a minimum of 5 minutes prior to application. This will ensure that the additives and aggregates are evenly distributed and the hydrophobic performance is optimal.

Using Heated Water for Mixing Basecoats

When preparing basecoats, use water heated to around 15°C. Warm water helps maintain an optimal consistency in colder conditions, supports a smoother application, and aids the initial curing process. Use a kettle to heat water, then allow it to cool slightly to reach the target temperature. Avoid boiling water, as excessively hot water can affect the basecoat’s consistency and cause premature setting.

Incorporating a Render Accelerator in Topcoats

Adding a rendering accelerator to the mix can shorten the drying time for topcoats, which is essential for projects in colder or humid conditions where drying is slower. Ensure the surface is fully dry and the basecoat has a moisture reading below 18% before applying the topcoat. Excess moisture in the basecoat can slow drying, weaken adhesion, and lead to issues like blistering or cracking. Use a moisture meter to confirm the basecoat’s readiness, ensuring it’s below the required 18% threshold before applying the topcoat.

How to use render accelerators to help winter working

Render accelerators are a renderer’s best friend in the winter period as they help to alleviate many of the issues that plague working times. Our render accelerator comes in 100ml bottles, and one bottle should be mixed into every bucket of silicone render prior to application. If you are spraying silicone render, you should pre-mix the accelerator into the bucket prior to pouring the mixture into the hopper.

1. Curing Time: Accelerators speed up the curing time of coloured-through textured renders, enabling faster job completion.
2. Layer Thickness: They create a thinner layer over the product’s finish, allowing it to dry normally without adverse effects from freezing temperatures.
3. Drying Time Reduction: Render drying times can be reduced by up to 50%, ideal for applications in colder weather (from 1°C to +12°C).
4. Aesthetic Integrity: No negative impact on the appearance of the dried