There is a season for everything. Painting the outside of your house is not appropriate during the winter season, unless you live in a moderate climate. Even if you live in the north and must do your outdoor painting during the warmer months, it is important to choose a good day for the job. Working on the wrong day can lead to problems such as flaking paint, runs, cracks and bubbles.
Optimal painting season for house exteriors is usually during the summer season. The weather is warm, rain is scarce, and in general, it is a weary task made more fun by the inclusion of sun and warmth–not to mention those steaks on the barbecue at the end of the day.
But if you cannot paint during that season, then when can you? How far can you stretch the painting season? Can you paint during the dead of winter? In this article I am going to talk about the painting problems caused by the change of weather.
What happens if you want to paint under direct sunlight?
Direct sunlight can degrade the binder and pigment of paint, resulting in chalking, erosion and colour loss. While all paints suffer these effects to some degree, lower quality paints and interior paints will generally fail in these ways much earlier than quality exterior paints. Waterborne paint binders usually resist the effects of direct sunlight better than the binders in solvent borne paints.
Waterborne paint binders tend to be ‘transparent’ to UV radiation, while solvent borne binders absorb the radiation. The radiation breaks them down. Some paint colours, such as bright organic reds and yellows, are more vulnerable to fading caused by UV radiation.
What happens if you want to paint when in a rainy or moisturised weather?
Changes in the moisture content of the substrate can also cause problems, especially with wood, hardboard and Plywood. When a wet substrate expands or a drying substrate contracts, it can stress the paint, resulting in cracking and flaking.
Permeable or ‘breathable’ waterborne paint allows the water to vaporize and escape. High quality waterborne paints with high binder content are very flexible, offering added protection against problems with cracking and flaking.
Water and moisture can also cause blistering of exterior paints, and create an environment that is conducive to mould growth. Top quality paints typically contain special additives called fungicides that help prevent mould from forming.
What are the problems of cold weather?
All paints get thick or more viscous in the cold and are much harder to use, especially solvent borne enamels. A solution to this problem is to add thinners, but this has the side-effect of reducing film build and, therefore, appearance. A better solution is to stand the paint in warm water, which makes it much easier to apply and helps get that smooth, brush mark-free finish that you want.
At lower temperatures solvent borne paints will continue to lose solvent but at temperatures about 3°C the chemical cross linking drying process will stop. The solvent borne paint will remain soft and be vulnerable to physical damage.
When temperatures return to normal, the solvent borne paint will continue its drying process. Heavily tinted solvent borne paints may flatten off in gloss if caught by sudden rises in humidity during the drying process.
Before setting up to paint, first check the weather. Wind and rain are the biggest obstacles. If these conditions are in the forecast, it is best to postpone this task. Temperature is another weather factor that painters must consider.
On a blistering hot day, the direct sunlight can get extremely hot. Intense heat can cause the paint to instantaneously dry upon contact, making it impossible to cover the surface smoothly. To combat extreme heat, start by painting areas of the house that are shaded.
Spraying is a technique to consider on really hot days – but this may require purchasing or renting expensive sprayers and pumps. The cold can also disrupt your paint job. Most paint brands suggest applying paint in temperatures above 50 degrees Fahrenheit, for optimal finish and coverage.
Amina Joseph is the author of this article and she loves painting. She has vast knowledge about painting and that is the reason she loves to write about this topic. She also has numerous article published on different media and this is another article she has written about painting. She also visited several website such as www.paintplace.com.au for her writing help.