20 Year Old Roof, What do I do

Hey John,
I have a 20 year old house and know that it will have to be replaced soon. Should the roofer do a tearoff or just lay new shingles on top of the old?

Audrey,
Depends on what is on there already. If there is only 1 layer of shingles and they are not curled badly then it is ok to go right over them. On an older roof such as yours you do not have the new ice and water shield, which would be installed if they were stripping it. If your roof is a simple hip or gable without a lot of ice traps and if you have no leaks now, then I would say just go over it.
On the other hand if you have 2 layers already then you must have it stripped. Make sure the roofing contractor installs ice and water shield in all valleys and along the gutter edge.
Ice and water shield is a rubber membrane 3'wide and in rolls of approximately 50'. It has adhesive on 1 side to stick to the roof then shingles are placed over that. You do not want to put it over the entire roof because rubber doesn't breathe and the roof needs to breathe. While they are at it make sure you have adequate attic ventilation, 1 sq ft (1 square vent you see on the roof) per every 150 sq ft of attic floor. Hope that answers your question. If not write back