In this final installment about insulation we'll take a look at the family of rigid boardstock materials. Unlike fiberous or spray-foam insulation that is installed in wall or ceiling cavities between the studs, rafters, or joists, boardstock insulation is applied either on the interior or exterior surface, spanning across the framing.

This press release just came through; sounds like it will be a pretty great resource. It's not up yet though — check it out in a few days.

Last week's column addressed cellulose insulation, which is the greenest and one of the most effective insulation materials available. But it isn't always practical or affordable to install cellulose. To insulate walls with cellulose, it's usually necessary to hire an insulation contractor, and if the job is very small--bumping out and reinsulating one wall of your home, for example--the cost may be prohibitive for that small improvement. This is where batt insulation makes sense.