CSLB C-39 Roofing ContractorFlashing, Ventilation and InsulationMedium
A chimney measures 36 inches wide on the upslope side of a composition shingle roof. Per code, what flashing detail is required at the high side of this chimney due to its width?
- AA single continuous piece of step flashing
- BAn additional layer of underlayment only
- CA drip edge extension at the chimney base
- DA cricket (saddle) to divert water around the chimney
Show answer & explanationAnswer & explanation
Correct answer: D. A cricket (saddle) to divert water around the chimney
Code requires a cricket, or saddle, be installed on the upslope side of chimneys (and similar roof penetrations) 30 inches wide or greater, measured parallel to the ridge, to divert water and debris around the obstruction rather than allowing it to pond.
Why the other options are wrong
- A. Step flashing alone does not address water diversion for wide upslope obstructions.
- B. Extra underlayment does not solve the water-diversion problem a cricket addresses.
- C. Drip edges are unrelated to upslope water diversion around a chimney.
Chimney Cricket (Saddle)
A cricket is a sloped, ridge-like structure built on the upslope side of a chimney or other wide roof penetration to divert water around it and prevent debris and ice accumulation.
- Required when the upslope obstruction width is 30 inches or greater.
- Built with sheathing and covered in matching roofing and flashing.
- Prevents standing water and debris buildup on the high side.
Memory trick: 'Thirty inches or more, build the cricket, that's the law.'