The most common defect we see is improper or inadequate caulking. Caulking is needed for both the exterior and interior of the home. On the exterior where window and door frames meet wood siding on an exterior wall should be caulked. Openings, gaps, and cracks in siding, stucco, masonry or your foundation (for larger gaps, use an expanding foam sealant such as those made 3M) should be caulked. Don't forget about the openings where vent ducts, air conditioners, plumbing or wiring come through the building. Don't caulk the undersides of window trim, door trim, or siding such as clapboards. If there is moisture trapped in the structure this gives it a way out. Inside make sure where the backsplash meets the counter and wall is caulked. Caulk around the sink, where it meets the countertop. Where the tub or shower meets the surround, the wall, and the floor. If the surround is more than one piece, the corners may also need to be caulked. Holes where the plumbing comes through the wall or floor. They will often be covered by decorative plates, so check to make sure they were caulked. When choosing what caulk to buy remember that you get what you pay for. Cheaper products will degrade faster. Most homeowners can tackle this but if you’re not comfortable a general contractor can complete this project too.