After surface preparation and selection of the primer, the type of vapor retarder is selected based on the direction and degree of vapor transmission and the intended location of the SPF application. Insulation for steel buildings that use vapor retarder facing limits the passage of water vapor and prevents it from condensing within the insulation.

For instance, for steel buildings used as cooler, a vapor retarder is very likely to be required especially if the SPF is applied to the buildings’ exterior surfaces, which represent the warm sides of the buildings. On the other hand, for steel buildings located in cool climates that need to be heated, a vapor retarder will prevent condensation if the SPF is applied on the buildings’ interior surfaces.

The selection of a vapor retard is based on the following conditions:

1. Amount of perm rating required, which is based on vapor transmission and perm ratings of other component parts
2. Compatibility with adjoining materials
3. Recommendations from manufacturers

The next step is to select the SPF system. This insulation material for steel buildings, forms a seamless layer when sprayed on a substrate. The the thickness of the sprayed material depends on the specific insulation requirements. Typically, the contractor fabricates the product on site based on the manufacturer’s directions.

There are numerous varieties of SPF systems on the market today that are available in various densities, each of which exhibits different temperature limitations, combustibility features, etc. For economical insulation installations for steel buildings, SPF systems may be combined with each other or with other insulation materials.

(to be continued)