Blog Archive: November 7, 2012

The bitter cold of winter marks the time to rethink that garage door.

This is the season when homeowners usually make efforts to seal up the biggest opening in the home. It’s also a popular time for garage door replacement. It’s that time of year when weather has a distinct effect on the garage door business.

Steel isn’t a good insulator, so to compensate; manufacturers double up the panels and fill the space between them with polystyrene or polyurethane insulation. Polyurethane insulates better than polystyrene, but it tends to break down after a period of time, whereas polystyrene lasts forever.

Polystyrene is a flat, sheet-like material, similar to a Styrofoam cup. Polyurethane is pumped into a door as a liquid, then expands and fills the space between the metal sides of the door. There are some synthetic problems with polyurethane. It can dry erratically, leaving unprotected spots in the door. That problem is detectable when a homeowner sees granulated polyurethane draining from the door. A polyurethane-lined door, however, can often have a better R-value than the rest of the garage.

Polystyrene has a lower R-value, the insulation rating system, and also is less expensive. Single polyurethane doors are rated around R-15 and cost more.

Insulation [more]