Oil canning is an inherent part of light gauge (26 gauge and 24 gauge) cold formed metal products, particularly those with broad/wide surface areas. These profiles, which have a wide flat surface area, are referred to as “architectural” roofing and siding panels and are often installed over a solid plywood substrate. The plywood substrate, if not completely level, could cause a perfectly flat metal roof/siding panel to show oil canning. This is caused by the pulling effect downward of the internal clip to a non-level surface causing stress on one side of each panel. Fasteners that are over- driven or of incorrect height can severely restrict movement, especially for long or wide panels. This rigidity can transfer stress to the panels through the thermal variations, creating visible deformations. Give me a call 215-534-8455...I need to ask other specific questions to help you get to the bottom of whether or not its the metal panels, the deck, the installation or all of the above. Brian
Brian Partyka
2016-02-22 19:46:08.000000
I recently completed construction of a new home which included installation of a 24 gauge standing seam Galvalume roof, installed over roof decking (4 X 8 - 7/16” OSB with ply clips at mid span). While I understand some oil canning is inevitable, I believe the amount on my roof is excessive. The installer indicates it is not abnormal and is not willing to replace the panels, but my contractor is willing (using the same installer) to do it at their expense.
My question(s), is the amount of unevenness in these photos considered "normal"? If it is not normal, what is the likelihood of replacing the panels with new ones, including a foam backer rod, will reduce the oil canning in a material way? Should I get a second opinion from another roof installer? I suspect I have one shot at getting this right before everyone starts pointing figures at each other.
Any advice would be greatly appreciated.
RETURN TO I Have An Existing Metal Roof and Have A Question
