Bar Joist Insulation
Bar Joist buildings are often times insulated on the underside of the roof deck to increase the building's energy efficiency. Metal bar joists vary in depths and shapes, therefore, attaching the insulation to the bar joist building can prove to be limited in comparison to a common metal building. The method used to secure the insulation is at the building owner's discretion. Bar joists are typically deeper than 12" and to prevent condensation you do not want to create airspace between the roof deck and the insulation, unless you ventilate. Because of this it is best to secure the insulation blankets tight up against the roof deck. There are a few options available to achieve this.
Bar Joist Clips
This is an easily installed, attractive system which requires very little hardware. Bar joist support clips are secured to the top of the joist and hang down. Banding is fed through the bottom of the clip, holding the blankets in place tight against the roof deck.
Steel banding can be screwed with a heavy duty screw to the joist securing the fiberglass blankets in place. Be sure to ventilate if you are creating airspace between the insulation blankets and the roof deck.
Stick Pins with Adhesive
Stick pins are adhered to the roof decking 1 foot apart. The adhesive has a 24 hour dry time. Once it is dry the roof insulation can be hung and friction washers hold the insulation onto the pins.