The cold and wet conditions are synonymous with the winter season in the Western Cape and although it is possible to take on external refurbishment projects it is of utmost importance to take special precautions when applying coatings .
So the question is what can go wrong?
Any supplier will reiterate the key to any successful redecoration is preparation however during the winter months the key to me would be surface conditions. With the drop in the air temperatures and intermittent rains it creates a different dilemma with regards to longevity of the applied coatings.
The most common problem is blooming paint. This greyish, milky-coloured haze on the surface of the paint film is usually caused by moisture attack during drying particularly when painting too late in the day out of season. Applying coatings to a wet surface or not allowing the primer coating to cure properly will result in this flaming effect taking place.
With the average temperatures predicted for the next couple of months setted at 12°C drying times will at least double to 6 – 8 hours. Masonry primers could take up to 3-4 days to cure properly and even longer if there are residual moisture still trapped within the substrate. Coating to early, the primer coating will chalk and result in a lost of adhesion, causing the paint to fail.
To negotiate redecoration projects successfully during winter it is essential to plan for the following:
1. Curing times and coating conditions – Do not apply coatings during inclement weather or predicted. Coating should not commence before 10:00am or after 15:00 in the afternoons. Do not apply coatings if the preceding coating have not cured properly
2. Humidity Levels – Coatings will not cure properly if humidity levels are exceeding the recommended atmospheric conditions. Daily recordings using an Elcometer should form part of your quality assurance.
3. Interim washing – Interim washing is pivotal do ensure that there is no surface contaminates from salt laden air from rolling mists. Rinsing surface with fresh water will negate any dust debris and or salt deposits.
4. Moisture readings – Moisture levels should be conducted on an ongoing basis. Levels should not exceed the suppliers recommendations as moisture is the largest cause of paint failures within the construction industry. Do not paint over wet substrates and always consult your supplier before applying coatings.
By following these guidelines you should be able to complete your refurbishment project successfully this winter.