Sashco Log Jam Acrylic Latex Chinking Caulk, 5 Gallon Pail, Mortar White (Pack of 1) Stretches up to 250% of original joint size without tearing  moves with your logs when they move Textured to simulate old-time mortar Easy to tool and cleans up with water Superior early water resistance Wont melt Styrofoam bead board  no more bumpy, unsightly chink lines Trusted go-to log cabin chinking  used on thousands of homes worldwide since 1985 Freeze-thaw stable: OK to leave in your truck overnight