Fiberglass Insulation Options

Insulating Steel Buildings & Metal Roofs

Insulation Blanket Thickness / R-Values

The higher the insulation blanket thickness, the higher the R-Value of the insulation. R-Value is a measurement of the effectiveness to retard or prevent the loss of heat flow. To achieve high R-Values a double layer system can be applied

Single Layer Insulation Systems

There are several thicknesses for single layer insulation blankets.


Insulation Thickness R-Value
2.75" R-8
3" R-10
3.5" R-11
4" R-13
6" R-19
8" R-25
9.5" R-30

Click Here To See Single Layer Systems for More Info.

Double Layer Insulation Systems

Multiple layers can be applied to achieve higher r-values. Your purlin depth determines the thickness of your bottom layer.

Double Layers R-Value
3" + 6" R-29
3.5" + 6" R-30
4" + 6" R-32
2 5/8" + 8" R-33
3" + 8" R-35
6" + 6" R-38
3" + 9.5" R-40
4" + 9.5" R-43

Click Here To See Double Layer Systems for More Info.

Insulation Facings

There are several options available for facing materials applied to your fiberglass insulation. Facing materials are applied to fiberglass insulation blankets to serve as a vapor retarder as well as a protected cover over the fiberglass.

Click Here To Learn About Each Facing Type

Facings for Metal Building Insulation


Facings for Metal Building InsulationInsulation Facing Tabs

Tabs are the extension of the vinyl facing past the fiberglass insulation blanket, used to seal or create a finished edge for the seams. You can get 1-6” tab on one side of the fiberglass, or 2-3” tabs. Double faced tape can be added to seal the tab to next piece of insulation. In retrofit this is usually 3” on each side and 6" on one side in new construction. In RetroFit, It is either tucked up along the side of the fiberglass acting as a trim or used to cover the the purlin or girt. An option is to get a factory pre-applied adhesive on the tab, which the installer peels and sticks to the next blanket. This provides a clean seal to the seams and creates a vapor barrier.

Tabs for Insulation Facings