Caulk v silicone sealant

Silicone is a man-made polymer that is derived from silicon. Silicone sealant is a flexible, adhesive, and resilient to moisture. Some varieties contain a fungicide to increase resistance to mould growth. However, it cannot be painted over. It is suitable for sealing against moisture penetration in bathrooms and kitchens, for example around baths and showers, sinks and so on. It can also be used as a sealant around external doors and windows.

Caulk is a filler material commonly used by decorators. It has a variety of compositions, including rope, acrylic, vinyl and silicone. Caulk is also adhesive and a good sealant. It dries more quickly than silicone sealant, and acrylic caulk can be painted over, but it is not as flexible once dry and it shrinks slightly on drying (meaning a second application may be necessary). This means that caulk is suitable for filling gaps when decorating, such as around skirting and built-in furniture where little movement is expected and over-painting may be required.

[edit] Related articles on Designing Buildings

• Adhesives.
• Binding agent.
• Caulk.
• Fillers.
• Grout.
• Mastic sealant.
• Mortar.
• Sealants.
• Silicone.
• Plaster.
• Putty.