Sealant is a substance used to block the passage of fluids through openings in materials, a type of mechanical seal. In building construction sealant is sometimes synonymous with caulk and also serve the purposes of blocking dust, sound and heat transmission. Sealants may be weak or strong, flexible or rigid, permanent or temporary. Sealants are not adhesives but some have adhesive qualities and are called adhesive-sealants or structural sealants.
Self-leveling silicone firestop system used around pipe through-penetration in a two-hour fire-resistance rated concrete floor assembly.
Caulk or caulking is a material used to seal joints or seams against leakage in various structures and piping.
Silicone-based caulk on this upturned bathroom sink will spread smoothly, sealing the gap, when the sink is turned over and installed.
Dried-out caulking on the Severn trow Spry, now displayed on shore
The tools of traditional wooden ship caulking: caulking mallet, caulker's seat, caulking irons, cotton and oakum
A caulking mallet, tar pot and a piece of petrified tar found on board the 16th century carrack Mary Rose