When you see a part of your house that needs painting, the natural inclination is to just jump in there and get it painted. You may clean off the surface a bit and make sure you are using the right paint, but other than that, most people just start painting the surface after taking minor measures to ensure they are doing it right. What they may miss out on is the fact that wood surfaces need to be thoroughly prepped before you can expect paint to stick properly.
Wood can rot over time, and this is the biggest reason why wooden surfaces need special preparation. If you paint over rotten wood, then that rotten part of it will deteriorate over time and take your paint with it. You will be left with peeled paint and gaping holes that are a pain to fix up. You need to get rid of the rotten parts before doing any painting. That could mean replacing a large portion of your home’s exterior or interior walls. However, if you do not take the time to replace or remove the rotten parts, you will be wasting your time by painting over them.
You also need to consider that wood can get kind of rough over time, especially the wood on the outside of the house. It can be weathered and become incredibly rough, making it very hard for paint to stick to it like it should. That roughness can also make it difficult for you to paint smoothly over it. You can end up with rough looking, uneven patches of paint that stick out and make your house look unsightly. These tend to peel off or crack quickly, and you will simply have to repaint there later.
You want to take the time to prep the wood, and that often means sanding it down, especially if it has become rough. If you see rotten boards or sections, then they need to be completely replaced. You don’t have to worry too much about the colour of wood you are using, so long as it is of decent quality. You will be painting over it anyway. Just make sure that whatever wood you use is prepared properly as well. Just because you bought the wood new, that does not mean that it is ready for you to paint over it. It may need to be sanded as well.
Very rough sections may need extra paint, or some caulking put in to fill holes.
Certain kinds of wood are more likely to have spaces of holes that you need to fill in before you paint. You want a relatively smooth surface to paint on, but that’s not always possible. Just make it as smooth as you can, within reason, and then use paint that is designed to be applied to wood. The results should be fantastic, if you followed these guidelines.