If you're not a climber, then don't buy a climbing rope for doing roof repairs. If you're going to buy a rope for a very specific job, then you should get the right equipment for the job.
For about the same cost as a climbing rope you could get a full roofers kit that comes with a:
- 5 point safety harness
- 50ft lifeline
- anchor plate
- 3' shock absorbing lanyard:
A couple reasons why you shouldn't use climbing gear for roof repairs: If you slip, you are most likely going to end up upside down as soon as you slide off the roof if you're wearing a climbing harness instead of a body harness; You put your expensive climbing rope at risk of damage that will make it useless for climbing (nails, saws, getting stepped on, sharp edges, etc.) You risk overloading the rope with more shock when you take a fall on a short length, the dynamic qualities of a rope are most effective if you have a good length of rope to absorb the shock.
Unless your plan is to use repairing your roof as an excuse to invest in some climbing gear so you can get into climbing after, then I would recommend buying a roofers kit, and asking your roofing questions on this SE sitethis SE site.
If you are using the roof as an excuse to buy climbing gear (I come up with any excuse I can), then what you want to do is get a good single rope that's >10mm of whatever length you want, a chest harness, a personal anchor (lanyard/sling) and a mechanical ascender. Anchor one end of the rope to the ground on the opposite side of the house you're working on, either to a tree or your truck or something that's a lot heavier than you, then simply throw the rope all the way over the top of the house. Don't tie into the rope, instead put the ascender on the rope and tie into your harness with your personal anchor, then run it through a biner on your chest harness and clip it into the ascender. Voila, you've just rigged your own roofers kit out of climbing gear.
Roofers Kit:
