All houses eventually need fresh caulking. The purpose of the compound, often called caulking or caulk, is to seal gaps and cracks that develop between materials. Unless the openings are sealed, drafts can develop. Even worse, moisture can penetrate walls.
Any season except winter is a good time to renew caulking. In the winter temperatures are generally too cold to apply caulking. It flows poorly and will not harden when the thermometer dips below 50.Tour the exterior of the house to examine the caulking around door and window frames, where siding joins at corners and meets the roof and foundation, around wall and roof vents, skylights and chimneys, around outdoor faucets and where plumbing and electric lines enter the house. Cracked or loose caulking has to be replaced. Any missing from those areas has to be added.
Read caulking labels carefully. The most important qualities are life expectancy, whether the material can be painted and whether cleanup is with soap and water or a solvent like paint thinner.
A high-quality acrylic latex caulk is a good choice. Besides having a life expectancy of at least 20 years, it adheres well to most surfaces, is easy to apply without being overly sticky and accepts paint. A drawback is that the caulking sometimes shrinks rather severely.