The stiff white panels of foam insulating board make it simple to cut and install in many different places, from under a slab to a horizontal roof. Working through construction or retrofitted in an older house, the panels give an R-5 or even R-6 insulation value per inch, depending on the manufacturer. On interior and exterior walls the panels can easily be secured to walls to present a solid insulating barrier to hot and cold temperatures. Foam board is available in many different sizes and thicknesses, suited to home and commercial uses.
On New Construction
Unaffected by groundwater, the panels of polystyrene, polyisocyanurate or polyurethane insulate a foundation below grade while protecting its waterproofing or dampproofing system when the contractor backfills around it.
Retrofitting
Metal panels can also be retrofitted under low-slope roofs, adding additional insulation to protect your house interior from the heat in or out through the roof. When used on interior walls and ceilings, the panels must be covered with drywall to satisfy fire codes. When reroofing a older house, foam panels could be added under the roofing membrane to increase the R-value of the roof.
Concrete Forms
Insulating foam panels might be used as a member of the forms when pouring concrete walls. The panels are secured together with plastic ties and also stay in place after the walls have been poured. The mixture of foam panels and solid concrete supply an R-20 insulating value to the walls, which makes them a good choice for homes in very hot or cold climates.