torsion spring, converting single to dual - benefits?

[wrench]

our rollup door torsion spring broke. it's a single spring system. is there any benefit in converting (our present) single spring system to a 'dual spring' setup? I mean like, all other things being equal, would dual springs last longer? or offer me some other kind of benefit?

or, let me also ask this another way: is the system I'm describing below "supposed to have" a single spring, or would (ordinarily) a dual spring setup be recommended?

our home is 11 yrs old, we bought it new, it was a 'spec house' of -exceedingly- dubious construction quality (don't get me started... )

present (busted) spring is 2 ID x .250 X RHW x 32 long

door is steel, four panel, uninsulated, 16 wide x seven feet tall, and weighs 172 lbs (at height of my old 'sliding weight' doctors scale platform)

thanks very much for your help, guys :-)

[gdoorpro]

converting to double spring should add life to the springs, and should help keep the shaft from shifting to one side as the spring is stretched a little before setting the screws to help avoid jamming while opening and closing the door.

[mb123452010]

One to two springs.

just thought I would add to GD pro's response for any future readers. gaining extra life isn't as easy as putting another spring up on the torsion shaft. The spring you have now is rated for a specific amount of torque (in pounds per turn or IPPT). Usually a high cycle spring will simply be a larger spring that yields the same amount of IPPT. adding another spring may or may not be cost effective, but i do agree another spring will help with any torsion shaft sliding back and forth. check out my spring calculator to get an idea of how this works. http://www.prodoorsupply.com/v/conversion2.htm