Oil canning is a sight-line problem, not a structural one
A flat, smooth panel on a long span can look wavy. It is not a defect and it is not weak. It is foam showing through thin steel, and it is fixed at the order.
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On longer panel spans you get what the industry calls oil canning. The face looks like it is warping, and people take it for a defect. It is not. It does not touch the integrity of the panel. It does touch the sight lines, and some people do not like seeing it.
Where it comes from
The foam in an insulated panel is foamed in place at the factory. It cures with small undulations in it, and on a flat, smooth face those undulations wash through into the steel.
The factory checks smooth panels against the industry standard. Some undulation is acceptable on a smooth, flat surface. So a panel can pass and still show it.
Three ways to keep it out of sight
Go heavier on the steel. When we do a flat, smooth panel we put a 24 gauge face on it instead of 26. The heavier sheet knocks those undulations out.
Use a profile. A shadow line panel takes the undulations out of the sheet. That is one of the reasons the profile exists.
Emboss it. Look across the face of an embossed panel and you cannot see the waves.
Decide before the order
Smooth is the typical clean room choice, and some customers just prefer a smooth surface. That is fine. Order it with the heavier gauge.
What you cannot do is fix oil canning after the wall is up. The gauge and the profile are decided on the order, or not at all.
If the drawings call for a smooth face on a long span, tell us early. We will price the gauge that keeps it flat.
Watch it from the shop floor.
What oil canning is
Smooth or embossed
Sources
This piece is our own experience, from the shop and the job site. It cites no outside figure, so there is nothing here to source to anybody else.
Where this applies
- Kingspan panels and freezer floor board.QuadCore KS Shadowline and KS Flat cold storage panels, K-Roc mineral fiber panels and GreenGuard XPS freezer floor board, with Kingspan data sheets and quotes.
- Food processing wall panels, chosen by the room.Insulated panels for food plant rooms held cold, FRP or UtiLite PVC for wash-down rooms at room temperature. CLEANsafe and stainless faces. Cleveland.
- Insulated metal panels for rooms that hold a temperature.Insulated metal panels 2 to 8 in. thick at about R-8 per inch, fire-rated mineral fiber walls and Kingspan cold storage panels. Installed by us or material-only.
- Cold storage panels for coolers, freezers and cold rooms.Kingspan QuadCore insulated panels, 2 to 8 in. thick, foamed in place, R-32 minimum to -20°F, with trim and Jamison doors. Installed by us or material-only.