First lets get some bad notions taken care of. Many people think you should only stain wood, never paint it because if you paint it, it can't breathe and will not expand and contract. However, even if painted, wood siding will absolutely continue to expand and contract. In fact, that is why paint often peels and flakes from wood siding. The seasonal expansion and contraction of the wood breaks the bond between the wood siding and the paint. Also, it is important to note that unless it is the wood that is used for the structure of your house, not your wood siding, then you will not have to worry about structural failure at all. There is no connection between structural failure and expanding and contracting wood siding. The wood siding on a house is not supposed to act as a structural component. It is simply a skin that protects the structure from the elements. Keeping the skin of your home in good condition is necessary and you must maintain it with one of the two options, exterior paint or stain.

Thus, we can move on. When it comes to exterior paint or stain, it is not going to matter a whole lot which you use as long as your goals for the paint or stain are met. For example, a high quality paint or an epoxy fortified synthetic resin water repellent applied to a cedar siding will stop water from entering the wood. Thus both paint and a stain can accomplish the goal of water entering the wood.

When it comes to exterior paint or stains, minimizing or eliminating water penetration into the siding should be your primary goal. The aesthetic look of your home should be secondary. A house that has strong curb appeal does add value, but beware of making this your primary objective, and neglecting the important factor of durability.

Let's take a look at some other factors that will or at least should effect your choice between an exterior paint or stain. Paint is a coating. A paint is considered a film that lays on top of the surface. The problem with films or surface coatings is that they eventually peel. When this happens, you are forced to scrape or strip the loose and peeling film off before you can apply a second coat. For this single reason, I try to avoid coatings that are films. Thus, if you go with paint, you want to get a high quality paint that will not need to be reapplied every few years, otherwise you are in for a lot of work.

Should you choose to go with a water repellent, you should know that penetrating water repellents do not peel, but they wear out. When it is time to re-coat the wood, you do not have to scrape the wood, which saves a tremendous amount of work. However, no matter which coating you choose to use, you will still be faced with lots of other work. You will still have to carefully and thoroughly wash the siding with soap and water and then do what is necessary to apply the coating of your choice. Scraping or stripping loose films is simply an additional step to a process. Thus, regardless of your choice, whether exterior paint or stain, buy a high grade version so that you can do this work less often.

Should you choose an exterior paint, know the work that lies down the road, and push it as far back as you can. You can do this by using a paint that contains a blend of water-based urethane and acrylic resins. These are very sticky and if used properly it will be many years before your paint film peels or blisters.

Aesthetics is important, keep in mind that painting or staining may significantly change the appearance of the structure. Certain architecture styles lend themselves to a certain look. For example, a log cabin and A-frame, are better suited for a rustic wood look, and thus a stain. However, if you have say a two-story colonial or Victorian, the image that comes to mind is not stain but is paint. If you paint your A-frame, will it lower it value to a potential buyer? That may not concern you, but it could be a factor in another person's mind. So, consider all of this in your decision making process before you purchase an exterior paint or stain.

Another thing to consider is the delicacy of what you choose. For example, If you do decide to paint instead of stain, be sure you hand wash the siding of your house as you would your car. Don't use pressure washing as the wood can be somewhat delicate. You need the wood to be perfectly clean. Also, read the label of the finish paint and follow the directions as to any primer they say you must use. Never forget that paint is simply a glue with color added to it. Both the primer and the finish paint must be the best glues and they stick best to clean surfaces. Don't shortcut yourself by buying high quality paint then applying it to a dirty surface.

Beware that some stains are made from natural oils that are food for mildew and algae. So, for your exterior job, look for stains that are made from synthetic resins.