Caulk Types Explained: Which One Goes Where

The wrong caulk fails fast. Here is a plain guide to what each type is for.

Silicone for Wet Areas

Silicone stays flexible and sheds water, so it is the standard choice around tubs, showers and sinks. Mildew-resistant formulas last longer in damp rooms.

Silicone cannot be painted, so choose a color that matches your fixtures.

Acrylic Latex for Trim and Paint

Acrylic latex caulk is easy to apply and clean up and can be painted. It is the usual choice for baseboards, door casings, crown molding and interior gaps.

It is not as flexible as silicone, so it is less suited to wet or fast-moving joints.

Polyurethane and Hybrid for Outside

Polyurethane and hybrid sealants bond hard to masonry, wood and siding and handle weather and movement. They suit exterior windows, doors and siding joints.

For wide gaps we add backer rod so the sealant does not sag or crack.