I am going to direct this article toward the exterior. There are a few big mistakes on the exterior of homes that I commonly see which fall into the preventative maintenance category. These are items that may seem harmless and easy to overlook but I can tell you from experience that they can end in very costly repairs down the road.
The first one I will mention is to keep trees and shrubs trimmed back off the house. Trees need to be trimmed back substantially for a couple reasons; if you have limbs actually hitting the roof it is an open highway for the cute little squirrel to make his way into your attic and take up residence. Believe me you do not want this!! I had one client that battled squirrels in his attic for five years and still could not get rid of them. Limbs on the roof will also keep shingles wet and allow mildew to grow there. Shrubs should be kept trimmed back at least two feet off the house. This will prevent a safe harbor for insects to build nests and possibly enter the house. It will also keep the house from drying thoroughly when it rains, which invites mildew and dirt.
The second one is to keep an eye on the caulking around windows, doors and siding corner boards. Take a look around once a year. If you see cracks in the caulking then it’s time to act. If left alone these cracks can get bigger and actually allow water to get in and rot your framing. The best caulk bar none is a urethanized caulk that stays flexible. These caulks will not crack. When painters used a cheap latex caulk it gets harder as it ages and is much more likely to crack. Many times you can apply new caulk over the old as long as there is no damage.
The third and probably most sneaky one is to keep an eye on your gutters. Walk the house every six months or so and take a look at your gutters. If they are not securely fastened water can spill over behind them or over the front and actually undermine the foundation of your house. It can also allow water to get in and rot out your soffit. If downspouts are not properly routed away from the house it can cause erosion of your yard or it can actually undermine the foundation as well. If enough water is constantly pouring up against the house it can wash away the dirt at the house and create a slope toward the house. This can allow water into basements in some cases and I have seen poured concrete walls leak into basements.
Living in a house without keeping an eye on things is sort of like driving your car without changing the oil. It’s guaranteed to come back and bite you later!!