How to Properly Install a Metal Cricket on a Standing Seam Roof
Crickets are low extensions from a roof surface designed to divert water from a penetration, such as a chimney, to prevent pooling or puddling, which can lead to leaks. On asphalt shingle roofs, crickets are framed in a triangle with wood, covered with roof decking and shingles. The point of the triangle is placed in the center of the chimney to force water to the sides. This technique will not work with standing seam metal roofs, because the metal roofing cannot be bent around a raised frame as shingles can. Metal roofs need specially formed crickets or diverters.
Match the cricket or water diverter to the size and type of roof penetration. Put circular diverters over openings such as plumbing vents or exhaust pipes. Obtain material from the manufacturer of the standing seam roofing and follow recommendations for fastening. Most types have some rubber or similar material on the bottom and are secured to the metal with adhesive.
Install curbing around chimneys and similar large openings. Match the curbing to the roof profile. Obtain a style with inlets in the bottom to fit over the standing seams. Use a layered approach, with a structural base secured to the panels, with mechanical fasteners or adhesive, and a second "floating" curb to divert water but accommodate movement.
Put curbs all the way around a chimney with a cricket welded to the high side. These typically have a bent metal flashing on the bottom. Fasten these on all four sides of the chimney or similar opening with adhesive or mechanical fasteners, according to the manufacturer. Place these between standing seams if possible, with the tapered cricket on the high side. Put the bottom flashing edge of the curb and cricket under roofing panels on the high side and edges, and put them over panels on the low side.
Things You Will Need
- Flashing, curbs and diverters
- Adhesive or other fastening
- Always start a standing seam cricket installation by checking with the roofing manufacturer to make sure curbs and other elements match the roofing panels and to ensure installation techniques will seal against all water penetration.