How to caulk siding Caulking Home Siding Properly preparing and choosing the right products is crucial to the lifespan of any project. If the foundation is not setup properly, your project will ultimately fail prematurely. There are no shortcuts. Preparation is the foundation The key here is to prepare the site for new caulking. The old caulking has to be removed entirely to make the proper adhesion between the boards. As you can see in the photograph (right) the previous caulking began to fail. According to the homeowner, the previous painter performed the job about 2 years prior to our arrival. What type of caulking do I use? The correct type of caulking will save money, although it may cost a little more, it will be worth it. For exterior, you want to use a caulking that is rated for your project and the materials being caulked. For example, you wouldn't use a kitchen and bath caulking to seal the exterior siding of the home. The Paint Bros in Grants Pass prefers