Re-roofing it is not particularly hard to do, but it is a monotonous job and sometimes an unpleasantly hot and sweaty job. Re-roofing your home can be very time consuming. There may be preliminary work involving roof board replacement, or new flashings or roof gutter replacements.
You should probably not consider re-roofing your house alone unless your home is a simple one story. Often it is beneficial to have someone to help get the shingles to the rooftop and do other assisting jobs.
If your roof has only one or two layers of roofing, and the roof sheathing boards are in good condition without evidence of moisture damage, you can probably roof right over the existing roof.
If the lower eaves areas have sustained moisture damage, it is a good idea to remove the old roofing in a strip about 2 to 4 feet wide along the roof eaves. Any damaged sheathing boards in this area can be replaced, a couple layers of a building felts cemented down, and shingle re-coursing that comes up the old shingles can be applied before proceeding with the re-roofing work.
Remove poor conditioned and damaged shingles and pull out any nails. Be sure to remove protruding shingles and patch over low spots first. The new roof will reveal all the bumps and valleys if not fairly smooth.
When covering an existing roof of composition shingles, try to match the shingle pattern that is already on the roof. Replace the old shingles with new shingles with the same thickness to achieve a smooth roof. Remember to use 1 ΒΌ inch nails. Complete the roof the same way as for a new roof, butting each course of new shingles up to an old course.
