You can, but it is not recommended. It used to be done all the time when asphalt shingles first started to be used. It makes for a lumpy roof and will puncture easier from hail or being walked on.
With composition shingles, no felt is necessary between shingle layers. When the exposure of the shingles is the same as the old exposure, the bottom edge of the old shingles is used as a guide for the upper edge of the new shingles in placement. This ability to place the shingles would be lost if covered with felt.
No
When asphalt shingles were first used, it was done all the time. The problem is that the shingles will not lay flat which give the roof an uneven appearance and makes them much easier to puncture by walking on them or with hail. No one does this anymore, strip off the cedar and put plywood or OSB over the space sheathing. More work and expense, but worth it in the long run.
Shingles is present all over the world.
cupping - improper installation of shingles over existing shingles
yes you can place new shingles over old shingles as long as the first layer of shingles are not curled....you will need 1 1/4 - 1 1/2 roofing nails..and 2 courses is the limit...follow same procedure as first roof installation
if wil go all over the place then you gone look slow
Specifically, No, shingles aren't needed. When laying Ice Guard, it should be installed over/or under the tar paper, and under where the shingles "will " be installed. You could wait for probably up to a month afterwords to install the shingles over top of the Ice Guard.
The last Shingles outbreak spread all over Europe it was about 15 yrs ago
No. Shake it Up is over
No because Shake It Up is OVER!
No, they cannot. There are no separate strains to encounter. However, shingles have been known to recur over intervals of months to years, with no obvious stimulus.