Step 14 : Radiant Barrier Insulation

Radiant Barrier insulation is what you should use if you’re going to insulate a steel building. Exactly how it works and why it’s more effective is better left up to the expert advice of an Absolute Steel building consultant so we’re not going to get into that right now. Also, it is an optional item and is not included with our standard building kit but because some people order it along with the building, we’re going to show you how to install it. For the purposes of this installation demonstration, we’re only going to be putting insulation on one wall but we’ll explain how to install insulation on the whole building.

Installing insulation is done in conjunction with installation of the exterior panels. As such, it wouldn’t be a bad idea for those who have purchased insulation with their building to first watch this chapter, then watch the complete section on installing the exterior panels and then come back to this before putting your insulation on.

For those of you who did not purchase insulation with your building, you can skip this chapter and move on the next which shows you how to put on your exterior panels.

Roughly a ¼ inch thick, this insulation is designed to be put directly on the frame before you put the exterior panels on.

It is held in place using the double sided tape that was included in the purchase of the insulation. The white side of the insulation goes towards the interior of the building. Adhere the double sided tape to the 2 inch x 3 inch frame members and to the top of the first purlin. Your insulation is 48 inches wide and is going to run vertically.  That way, as you get a row of insulation on, you can then apply a sheet of the exterior panel over it. This will prevent the wind or elements from damaging the insulation.  This is very important—applying an exterior panel over each length of insulation as you go. If you don’t, you’re liable to have all the insulation come down with a bit of wind.

Which brings me to an important point; don’t try installing insulation on a windy day.

When installing insulation or exterior panels, always start at the left side (as you’re facing the wall) of the gable (peaked) walls and work towards the right.  We have the panels sized to work this way. For the sides, start at the front and work toward the back on both sides.  Take a measurement from the bottom of the base rail to the top edge of the first roof purlin and cut a length of insulation to match. You might want to cut the first piece a little long and put it in place on the building to check the fit. Adjust your length and then cut all the remaining pieces for the side walls.

When applying the insulation to the frame, always start at the bottom and work your way up. The edges of the insulation should fit together tightly and overlap slightly, try to keep your insulation tight and without sags or wrinkles in it.

Next, place your exterior wall panel over the insulation and screw right through the exterior panel, through the insulation and into your building frame.

Trimming Insulation Around Doors and Windows

When you get to the door and or window openings, you’ll need to trim the insulation. Using the utility knife, trim the insulation even with the edge of the where the back flange to the J Trim is going to be. Use some of the single sided tape—the tape you’re using to cover the interior seams of the insulation to hold the insulation in place because you must leave room for the sheet metal panels to fit inside of the J Trim.

Installing Insulation on the Front and Back Walls

Measure and cut insulation slightly longer than you need to run from the base rail at the bottom to the roof frame at the top. Or, if you doing the rows that run from the top of the door to the roof, use the door header as the bottom.

Put your double sided tape on the front of the roof frame, along the base rail and/or the door header if doing those sections that run from the door up to the roof. Also, it’s a good idea to put some here and there on frame pieces just to make sure it stays up there until you get the exterior panels on.

Installing Insulation on the Roof

Starting on the side of the roof that’s directly above the first side wall panel you installed, put the double sided tape on top of the side insulation where it attaches to the first or lowest purlin.

Now run another strip of the double sided tape on the top section of hat channel or purlin that’s on the other plane of the roof—that’s right, up over the peak then put it to the highest section of hat channel. Measure the insulation to fit the entire length, leaving a little extra just in case you need it. Pull all the wrinkles or slack out of it and then affix the exterior roof panel over the insulation and into the frame. So that’s what we’re going to keep doing: installing the insulation one row at a time, then affixing the exterior roof panels by putting the color coordinated panels screws through the panels, then through the insulation and into the frame…then moving along to the next section or row.

On the other side of the roof, put the double sided tape on the top of the side insulation and then on the top edge of the roof insulation from the other side of the roof. Measure and cut the insulation to extend slightly over both strips of tape.  Install the exterior panels as you go.

Now on the inside of the building, use the single-sided white or “scrim” tape and run that over any of the seams. When you come to an interior frame piece, use your razor knife to trim any excess that gets stuck to those frame parts. Be sure to evenly and firmly press the tape, especially against the seams so it adheres properly.

Step 15: Side Exterior Panels

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