Roof Chimney Cricket Design

If your chimney doesn t have one watch for holes rusting through the flashing.

Roof chimney cricket design. When a roof is generated automatically crickets will not be produced but they can be drawn manually using the roof plane tool. To create a manually drawn chimney cricket. Chimneys shall be provided with crickets where the dimension parallel to the ridgeline is greater than 30 inches 762 mm and does not intersect the ridgeline. The functionality of the cricket is determined by the cricket valley slope.

The codes however don t say anything about the ideal pitch or slope angle of the cricket. Roof crickets sometimes called saddles are raised roof planes built to divert water or snow. Cricket panel slope is typically double the roof surface slope. What is a chimney cricket a chimney cricket is a metal or wood frame that is used to change or divert the water flow where the roof and chimney meet.

A properly installed chimney cricket will direct water and debris around the chimney and off the roof. Jun 15 2017 explore anibal carbonell s board roof cricket on pinterest. All flat backed chimneys hold water which in turn causes water backup similar to a dam. A chimney penetrating a roof with a slope of 6 12 must be protected by a cricket with the height of 25 percent of the chimney s width.

As the minimum width required for chimneys is at 30 inches the cricket in this case must be 7 5 inches tall. Roof crickets can be covered with metal flashing or with the same material as the rest of the roof. Crickets shall be constructed in compliance with figure r1003 20 and table r1003 20. This can cause wood and siding damage around the bottom perimeter of your chimney along with roof leaks.

The roof cricket is normally the same pitch as the rest of the roof but not always. Cricket angle the angle x between corresponding lines ab cricket length and ac cricket valley design guidelines. The intersection of the cricket and the chimney shall be flashed and counterflashed in the same manner as normal roof chimney intersections. Mark the height of the cricket on the back edge of the chimney.

A roof cricket is a ridge structure designed to divert water on a roof. The height should be at least as high as the slope in order to direct water away from the chimney so if the slope is 4 in 12 place. Depending on the roof surface slope there is an accepted maximum length to width ratio. Roof crickets are found on the high side of a chimney or when one roof meets another.

If you re getting a new roof be sure the contractor s bid includes a cricket. Dormer vents can be created using a similar technique.