Pipe collars help stop fire and smoke from spreading through plastic pipe penetrations in fire-rated walls and floors. Both cast-in and retrofit options work effectively when they’re properly tested and installed the main difference is timing. Cast-in collars are installed during construction, while retrofit collars are used after the building is complete, often for upgrades or fixing missed fire stopping. Most issues don’t come from the product itself, but from using the wrong type or installing it incorrectly. Planning ahead can save time and money, and retrofit collars provide a practical solution when changes can’t be avoided.