Saddle flashings must be flanged how many inches up the wall and chimney and how many inches onto the roof?

Saddle flashings must be flanged how many inches up the wall and chimney and how many inches onto the roof?

• A. 2 inches up; 2 inches onto roof
• B. 4 inches up; 4 inches onto roof
• C. 6 inches up; 6 inches onto roof
• D. 8 inches up; 8 inches onto roof

Answer: (B)

Saddle flashings are designed to seal the joint where a chimney or vent meets the roof and wall, directing water away from that intersection. Extending four inches up the wall provides enough height to be covered by siding and to shed water down the vertical surface, while extending four inches onto the roof ensures the lower edge is captured under the roofing material to create a solid barrier against leaks. Smaller amounts, like two inches, can leave a vulnerable seam, and larger amounts, such as six or eight inches, are usually unnecessary and can complicate proper overlap with shingles and siding. So, four inches up the wall and four inches onto the roof is the standard, effective dimension.

Saddle flashings are designed to seal the joint where a chimney or vent meets the roof and wall, directing water away from that intersection. Extending four inches up the wall provides enough height to be covered by siding and to shed water down the vertical surface, while extending four inches onto the roof ensures the lower edge is captured under the roofing material to create a solid barrier against leaks. Smaller amounts, like two inches, can leave a vulnerable seam, and larger amounts, such as six or eight inches, are usually unnecessary and can complicate proper overlap with shingles and siding. So, four inches up the wall and four inches onto the roof is the standard, effective dimension.