Red Seal Carpenter Practice Exam

When a chimney on a sloped roof is more than 750 mm (30") wide, what must be done to protect the roof from the build-up of snow at the junction?

1. Install a saddle.

2. Install flashing at least 150 mm (6") up the chimney.

3. Install a flat section of roof behind the chimney.

4. Install a membrane flashing up the chimney.

The correct answer is: Install a saddle.

The correct response involves the necessity of installing a membrane flashing up the chimney when it exceeds a certain width on a sloped roof. This measure is crucial for preventing water from penetrating the roof system. A chimney that is wider than 750 mm presents a challenge in snow management because it can create a pocket for snow accumulation at the junction with the roof. This accumulated snow, when it melts, can lead to significant water run-off, increasing the risk of leaks and potential damage to the roofing materials. By incorporating a membrane flashing, which is a waterproof barrier that effectively seals the junction where the chimney meets the sloped roof, you ensure that any water that may flow or seep from the snow melt will be directed away from vulnerable areas. This solution is tailored for substantial width situations, addressing the heightened risk of water intrusion that comes with a larger chimney on a slope. The other options involve different protective strategies, but they do not specifically resolve the unique concerns presented by a chimney of this width when it comes to snow accumulation and managing water flow effectively.