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Metal Roofing Va Oil canning

What in the world is oil canning? In the vernacular of metal roof installers oil canning is when a metal roof, particularly standing seam metal roofs, has bulges and ripples in it. This phenomenon occurs for a plethora (I always wanted to use that word in a blog) of reasons. The main culprit is the roof deck. Think of it this way, the deck of the roof is the bones and the metal roofing is the skin. However the bones lay, that is how the skin is going to lay. If the deck has as little as a 1/8 inch deflection then that panel will not lay flat. Here are some more reasons, if the master coil is slit with more tension on one of the decoilers then it will keep that tension in that coil and the panel won’t lay perfectly flat. Add to that humidity and when the humidity around the roof is different it will oil can.

These types of roof also expand and contract with heat or cold weather. A 50 foot panel will “stretch” as much as ¼ of an inch between the summer and winter months. In these panels we actually use clips that allow the panels to expand and contract. If you compare the new steel panels with the old tin panels you can see that we have made some headway on reducing oil canning. However we don’t think we will ever be able to eliminate it altogether.

For more information on oil canning and other elements of standing seam metal roofs please visit us at AlphaRain.com or call us at (540) 222-1642