Dear Henri: We clipped your column titled “Silicone caulk doesn’t stand up to polyurethane,” knowing that we would need the product you recommended — Sikaflex-1a — which we couldn’t find at Home Depot ...

Q: Thank you for your column, where I always learn something or find out about a useful product. We have a lovely stone-tiled walk-in shower; it has a pebble stone floor. Our problem is the caulk line ...