Caulk is useful for blocking air, moisture or waterinfiltration, helping prevent a number of problems in a structure. These include:

• Loss of conditioned air;
• Loss of humidity;
• Water leaks;
• Condensation; and
• Mold growth.

Caulk is applied to edges, joints, trim and any other place where narrow gaps may be found inside or outside the home.

Most caulk sold today is made of latex, acrylics, butyl or silicone, and sometimes combinations of these materials. Pure silicone caulk cannot accept paint, making it suitable for sealing bathroom fixtures and tiles or joints hidden within walls or frames. Butyl, latex, acrylic latex and siliconized acrylic caulks are paintable, so they’re ideal for use outside at corners and around trim, doors and windows. Siliconized products are less prone to shrinkage when cured than other caulks.

Gloves and good ventilation are generally recommended when applying all forms of caulk. Mask and eye protection are recommended when applying silicone caulks, which can give off a strong odor. See also caulk.