How old is your roof? What’s it covered with?
First off, when was the house built? This is simple logic. If the house is 15 years old, the roofing is too, right? Usually it is, but not always. If there have been roofing repairs due to wind or tree damage, usually most of the roof will be the same age as the house, with some newer roofing. You can usually spot a roof repair from ground level, due to differences is the color, wear, and even style of roofing used on the repaired area.
If the house is, say, 20 to 30 years old, or more, then the material of the roofing becomes the next question.
If the roof is asphalt and it is original, you can look forward to having roofing work done in the near future. Guaranteed, it will be a full re-roof costing you about 8 grand or more. You can spend less by roofing over the old roof; and if done right, you may get another 15 to 18 years of life out of the roof, but odds are the roof will be lumpy and bumpy.