Under what conditions should wrap strips be used?

Wrap strips should be used in situations where measured doses of intumescent material are required to effectively seal penetrations in fire-resistance rated assemblies. These strips are specifically designed to expand and fill gaps when exposed to heat, providing an effective barrier against the passage of flames, smoke, and hot gases during a fire.

In cases where precise application of the intumescent material is necessary, wrap strips allow for controlled coverage and ensure that there is enough material to perform as intended. This is particularly important because the performance of firestop systems must meet specific fire-resistance ratings and regulations to ensure the safety and integrity of the building’s fire protection strategy.

Other options suggest conditions that do not align with the product's purpose. For instance, wrap strips are not limited to permanent installations, nor are they meant for situations where no sealing is necessary. Furthermore, they are used in circumstances where a firestop is indeed required to maintain fire-resistance integrity, rather than simply when other firestopping methods are not applicable.