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TOPIC: Maintenance

Oil Canning

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I'm having a metal roof installed on my home (South Florida) and I am getting oil canning in SOME of the panels. They are installing a 24ga., 16" wide, MDA 1.5, standing seam, galvalume metal roofing system (with 2 "ribbed" grooves per panel). I was first told that it was because of my trusses (which their carpenter confirmed that it was not). Then I was told that "it's the nature of the beast" and it should smooth out after several months. I don't buy that. Why are some panels perfect and others are not. Also, some panels have a length of 18-20 feet and there are more good ones than bad. Most of the oil canning is happening in the short to moderate length panels. I know structual the roof is sound and it is strictly cosmetic, but do I have to accept it as "the nature of the beast" or is there a technically reason that I can go back to the roofing company and make them fix it? Thanks for your help!
Guest User

8/27/2002
I'm having a metal roof installed on my home (South Florida) and I am getting oil canning in SOME of the panels. They are installing a 24ga., 16" wide, MDA 1.5, standing seam, galvalume metal roofing system (with 2 "ribbed" grooves per panel). I was first told that it was because of my trusses (which their carpenter confirmed that it was not). Then I was told that "it's the nature of the beast" and it should smooth out after several months. I don't buy that. Why are some panels perfect and others are not. Also, some panels have a length of 18-20 feet and there are more good ones than bad. Most of the oil canning is happening in the short to moderate length panels. I know structual the roof is sound and it is strictly cosmetic, but do I have to accept it as "the nature of the beast" or is there a technically reason that I can go back to the roofing company and make them fix it? Thanks for your help!
Guest User

8/27/2002
I'm having a metal roof installed on my home (South Florida) and I am getting oil canning in SOME of the panels. They are installing a 24ga., 16" wide, MDA 1.5, standing seam, galvalume metal roofing system (with 2 "ribbed" grooves per panel). I was first told that it was because of my trusses (which their carpenter confirmed that it was not). Then I was told that "it's the nature of the beast" and it should smooth out after several months. I don't buy that. Why are some panels perfect and others are not. Also, some panels have a length of 18-20 feet and there are more good ones than bad. Most of the oil canning is happening in the short to moderate length panels. I know structual the roof is sound and it is strictly cosmetic, but do I have to accept it as "the nature of the beast" or is there a technically reason that I can go back to the roofing company and make them fix it? Thanks for your help!
Guest User

8/27/2002
I would ask that you look up our previous responses of August 16th and April 26th of this year and see if this helps. Just scroll down the questions and responses which are sorted by date. If this doesn't help get back to us again. Good luck.
Allan Reid
Dura-Loc Roofing Systems, Inc.

8/27/2002
Recently my company supplied metal roof panels for a project in Exuma, Bahamas. We also recommended the type of panel and an installer for the job. The panels are .032 Aluminum 1-1/2" Snap Lock with a nailing strip. The panels are 18" Wide and Longest run is 20'. The panels are installed on a residential beach home with a hip roof. They are installed on a 5/8" CDX Plywood substrate over wooden roof trusses. Unfortunately, the material has oil canned severley. Their is contention between the installer and contractor over the reasons the oil canning is so severe. The installer claims that the roof deck is not on plane. The contractor says that he believes this was not an appropriate panel system. He believes because the system is screwed through the nailing fin direct to the deck the panels are not allowed to properely relieve the stress of expansion & contraction. The contractor believes that because the panels are made from .032 aluminum and aluminum expands and contracts more than steel aluminum should not be rolled into a nailing fin panel. I should note that the nail/screw slots on the nailing fin are 1" long. and #10 x 1 pancake screws were used to fasten the metal panels to the deck. Nearly every panel on certain sides of the roof has oil canning in 2 or three places between the eave and ridge. The contractor believes their would have to be a dip in the plywood at each place oil canning is showing. The installer says this is not so. That if the deck has even a gentle "dip" that is more than 1/4" across a long plane it will cause the oil canning. The contractor has also said that the screws were fastened too tight. The installer says they had their screw guns set properly and that if the screws were fastened down too tight it would create a "reading line" at the over tight screw not the oil canning effect we are seeing. Is their a way of determining why a roof has oil canned? I know oil canning is inherent in metal roofing and is not a cause for rejection, but I also have seen enough roofs to know this much oil canning is excessive and is a sign of either a bad deck, improper installation or improper system for the application. Any advice you can offer would be greatly appreciated.
Guest User

8/23/2003
You have done a very good analysis and seem to have a good grip on the possible causes. Was oilcanning observed prior to installation? If so, then it is probably inherent to the metal the panels were formed from. If not, is it present at all times or is it worse when the panels are warm and expanded? If present all the time, it could be because of the fasteners being too tight. If it is worse when the roof is warm, I would suspect the structure or perhaps the screws not being properly centered in the fastening slots. This type of panel, being produced in aluminum, is not unusual. I would suggest hiring a third party inspector, well experienced in metal roofing, to do a personal inspection of the job.
Todd Miller
Isaiah Industries, Inc.

8/24/2003
May I send you a photograph of my roof for comment? When each perfect looking 12' wide, .024 gauge panel was laid onto the just installed panel (a two piece system rather than a three piece-two panels and a batten clip), the panell immediately formed 12 to 14 dimples or"oil cannings. It seems obvoius that each panel was forced out of alighnment as it was laid onto the previously installed panel. I thought oil canning was from the heating and cooling of the roof, or does the industry define all such distortions, regardless of cause, as oil canning? Thank you, Denis Fox
Guest User

5/10/2004
we can't accept pictures on the site however our provider forwarded them on. I guess we need more information to help you here. possibly you could contact me directly with the following information. 1) Was the product site rollformed? 2) If yes, the name of the machine and product. 3) If no, the name of the manufacturer Thanks, Al.
Allan Reid
Dura-Loc Roofing Systems, Inc.

5/10/2004
I have seen your pictures. I really suggest contacting the manufacturer of the roofing and seeing if they can look at this. Oilcanning can result from natural stresses inherent in the metal. However, it can also result from improper fastening (usually tight clips), poor substrate, and uneven decking. Oilcanning can become more noticeable with expansion and contraction and temperature changes. As for the staining from the chimney, depending up the type of pain system on your roof, this may or may not be a problem.
Guest User

5/10/2004
WHY DON'T YOU GO AFTER THE FLORIDA PRODUCT APPROVAL COMMISSION. THEY ARE SO ANAL ABOUT WHAT GETS PUT ON THEY SHOULD BE RESPONSABLE. MY MACHINE PRODUCES GREAT PANELS UP TO 40 FEET THEN THEY ONLY HAVE LIGHT OIL-CANNING. THE DIFFERENCE IS I CARE ABOUT MY PANELS AND HOW THEY LOOK. I CONSTANTLY ADJUST MY MACHINE TO KEEP THE PANELS CRISP. IT COULD ALSO BE THE INSTALLERS. THEY COULD BE TWEAKING THE PANELS SOME HOW. BUT IT'S MOST LIKELY THE MACHINE.
Guest User

12/10/2007
SHOULD HAVE USED A REAL PANEL. AND YOU SHOULD HAVE SOLD THE PEOPLE INTO .040. IT'S ONLY A LITTLE MORE AND DOESN'T OIL CAN NEAR AS BAD. NAIL STRIP IS NOT SUITABLE FOR A HOUSE WITH CHANCES OF HIGH WINDS. ESPECIALLY WITH .032. SORRY, JUST BEING HONEST
Guest User

12/10/2007